PL on Blueprint – What It Means and Compared to Similar Callouts [With Examples]

What does PL mean on an engineering or manufacturing blueprint?

PL is an abbreviation for places. This notation will be shown with a number associated with it such as:

Chamfer 0.010” x 45 degrees 4 PL

When the PL note is used, it should be very clear what feature, edge, etc. that the callout applies to. Unfortunately, what was obvious to the person drafting the print and what is obvious to the person down the line reading it, does not always match up.

When in doubt ask the customer or someone higher up the food chain.

PL example on a blueprint

The example below shows two chamfer callouts that use PL notation. 

manufacturing blueprint that shows two chamfers with PL callouts

This is just a section of the blueprint but the overall part shape is square. The 4 PL refers to the 4 edges on each side there the main surface (S1 & S2) meet the sides of the part. 

Therefore the part should be chamfered at 0.5 x 45° all around on one side and 2.0 x 45° on all around on the other side.

Blueprint notes that are similar to PL

The #x format (2x, 4x, etc) gets used often in place of the places note. The PL example given above could be changed to either of the following and the requirement would remain the same:

Chamfer 0.010” x 45 degrees 4x or Chamfer 4x 0.010” x 45 degrees

Related articles

// Symbol on Blueprints [What It Is, How To Check It & More]

What does the // symbol mean on a blueprint?

parallelism gd&t symbol
The GD&T symbol for parallelism

// is the GD&T symbol for parallelism. For the parallelism symbol, notice how the two lines of the symbol run together. They are parallel to each other. 

How to read a parallelism blueprint callout

The blueprint item that contains the parallelism callout is called a feature control frame.

The components of a feature control frame are shown below.

 

feature control frame description with parts identified

The parallelism symbol would be inside the first box to indicate the type of tolerance.

The tolerance amount is listed in the middle box. This tolerance is in the the same units that the rest of your blueprint is in. Many times this will be listed in general tolerance block of the blueprint.

The datum reference is the feature that the feature with the parallelism callout will be compared to. In the example below, datum A is on the left and the right side has the parallelism callout attached to it. 

This feature control frame reads “the right side of the part must be parallel within 0.02 to datum A”.

parallelism callout with feature control frame

How to check for paralleism

Other GD&T symbols

GD&T symbols are used to control the size, form and/or orientation of the different features on a part. 

Check out the list below to learn about other GD&T symbols and if you want a more in depth guide that includes then check out our Complete Guide to Blueprint Symbols

gd&t symbols
gd&t symbols

Related articles

26 Types of Micrometers [Includes Pictures & Descriptions]

Micrometers come in many shapes and sizes. 

Our comprehensive list covers all of the most common and many uncommon micrometers found in machine shops, garages and workshops around the world.

Read on to see how many you’ve used or how many you even knew existed.

The most common types of micrometers

Outside micrometers

anytime tools 1-2" micrometer
Anytime Tools 1-2" Outside Micrometer

Otherwise known simply as mics. Your standard everyday micrometer. Used for measuring outside diameters, lengths, widths, thickness, etc. Commonly available in 1” measuring ranges.

The typical accuracy of an outside micrometer is 0.0001”.

Inside micrometers

mitutoyo inside micrometer set
Mitutoyo Inside Micrometer Set

Used for checking internal widths, diameters, and bores. The typical accuracy of an inside micrometer is 0.001”.

Depth micrometers

Starrett Depth Micrometer

Used for measuring the depth of slots and holes as well as the location of various steps. They tend to be less accurate than a standard micrometer. Most will have an accuracy of +/- 0.001”.

Styles of micrometers

Standard vernier micrometer

The old standby. This type of micrometer has been produced for decades and I’m sure will continue to be around for many more years.

They feature a rotating thimble that has a vernier scale wrapped around it. This scale is matched up with the scale on the sleeve to obtain your measurement.

Digital micrometer

mitutoyo digital micrometer
Mitutoyo Digimatic Digital Micrometer

Many of the micrometers listed are available as a digital version as well. Do not expect anything different between a digital and standard micrometer other than the display.

They have the same accuracy. Digital vs non digital is just a matter of preference.

Mechanical counter/digital mics

mitutoyo mechanical counter micrometer
Mitutoyo Digital Counter Micrometer

A less popular option, some of the micrometers listed can be purchased as a mechanical counter version. Some of the manufacturers call them digital, but the term is misleading.

Personally, I have never found them superior to other mics. I would avoid them. You can expect their accuracy to be in line with a standard micrometer of the same type.

Micrometer sets

anytime tools micrometer set with case and reference standards
Anytime Tools Micrometer Set

Because micrometers have a smaller measuring range when compared to some other precision measuring tools such as calipers, they are often purchased as a set. Micrometer sets are commonly available in 0-3”, 0-6” and 0-12” varieties with many other less common sets being available as well.

Micrometers with different spindles and/or anvils

Carbide tipped anvil and spindles

Carbide tips provide additional wear resistance for a micrometer, especially one that may see extra heavy usage. While they can be useful in this regard, the carbide tips are more brittle and have been known to chip.

For most people, your standard stainless-steel spindle and anvil will be good enough but both types work well.

Non-rotating micrometers

These micrometers work well for a number of applications. The spindle on this type of micrometer doesn’t spin to increase the accuracy of the measurement. It also has the added benefit of being less likely to damage surfaces where surface finish is extremely important.

Micrometers with rounded anvils

These micrometers allow you to measure features that are not flat such as the wall thickness from the edge of a hole another surface.

Micrometers with interchangeable anvils

mitutoyo interchangeable micrometer
Mitutoyo Interchangeable Anvil Micrometer Set

Often seen on large micrometers. Interchangeable anvils usually allow a single micrometer to measure over a 6” range in 1” increments.

Imagine a 12” micrometer that can swap anvils to measure any 1” range up to 18” and you will get the idea.

Blade micrometer

mitutoyo blade micrometer
Mitutoyo Blade Micrometer

Blade micrometers are used for measuring narrow features such as grooves, slots and keyways. The spindle of a blade micrometer won’t rotate to allow accurate alignment and measurement of your part.

V anvil micrometer

These micrometers are used to check for an out of round condition, sometimes called lobing. They are often used in the centerless grinding industry.

Tube micrometer

anytime tools tube micrometer
Anytime Tools Tube Micrometer

Used almost exclusively for measuring the wall thickness of round objects such as…you’re never going to guess.

Alright, I’ll tell you. They measure tubes! Surprising, I know!

The anvil on these micrometers is more rounded than what you would see on a micrometer with rounded anvils

Pitch-diameter micrometer

These micrometers have a special anvil and spindle to allow them to measure the opposite sides of a thread. The anvil has a double v shape while the spindle is pointed.

They have an overall measuring range such as 0-1” or 1-2” like a standard micrometer but also have a range of threads per inch or mm that they are capable of measuring.

Multi-anvil or universal micrometers

Starrett Mul-T-Anvil Micrometer

These micrometers allow you to switch the anvil so that the tool can take multiple types of measurements. One multi-anvil mic can take the place of an outside, tube and rounded anvil micrometer all in one.

Groove micrometers

Groove micrometers are used for taking measurements of grooves and other small features. Their low profile allows them to be used in tight spaces.

Disc micrometers

fowler disc micrometer
Fowler Disc Micrometer

This type of micrometer is frequently used for measuring thin sections of a part such as a sheet of material or the ribs or fins on a component. Often, they come with non-rotating spindles to keep the thin material from being twisted and giving an incorrect measurement.

Micrometers with special frames

Micrometers with insulated frames

outside micrometer
Mitutoyo Micrometer With Insulated Frame

Heat can cause metal or other materials to expand. When this happens, your part can appear to measure larger than it actually is. The same principle affects your measuring tool as well. This is why many micrometers will have an insulated grip to keep you from transferring your body heat to the micrometer and affecting the measurements.

Bench micrometer

Bench micrometers work like a combination micrometer and micrometer stand. They are used when the part to be measured can be brought to the workbench and will provide all the same benefits of using a good quality micrometer stand.

Sheet metal micrometers

mitutoyo sheet metal micrometer
Mitutoyo Sheet Metal Micrometer

Sheet metal mics will allow you to take a measurement away from the edge of the material. Useful for working with, well sheet metal duh but also other materials where you want to get closer to the center of the part and need the clearance to be able to do it.

Hub micrometer

Hub micrometers are used when a shallow frame is needed such as when you need to insert the tool into a hole to take a measurement.

Micrometer head

mitutoyo micrometer head
Mitutoyo Micrometer Head

Micrometer heads don’t have a body or frame. They are used for all sorts of applications where an adjustment needs to be made with a great deal of accuracy.

Some common uses are for in fixtures as well as machine setup.

Special application micrometers

Crankshaft micrometer

A specialized set of micrometers that have a larger than normal measuring range that allows them to take measurements you might need when working with crankshafts.

This range is typically from 1 ½” to 3 ½”.

Disc brake micrometer

Another special application micrometer. They are used for measuring the depth of the grooves in your brake rotors. Like the sheet metal micrometers, they have a frame that allows measurements farther away from the edge of the brake rotor.

Paper gage micrometer

Used in the paper and printing industries, these micrometers feature wider spindle and anvils that help keep them from compressing the material being measured to make sure the readings are accurate.

Micrometer accessories

Micrometer balls

starrett micrometer ball
Starrett Micrometer Ball

This attachment allows a standard outside micrometer to function like a tube or rounded anvil mic. The attachments do reduce the overall measuring range of your tool so keep that in mind.

Additionally, you will need to subtract the size of the micrometer balls into consideration when calculating your measurement.

Micrometer stands

grizzly industrial micrometer stand holding micrometer
Micrometer Stand Holding A Micrometer

Micrometer stands can give you a third hand when using your micrometer. While they work well to give you more freedom for maneuvering your part, they also help to reduce any heat transfer to the micrometer which could affect your measurement.

Related articles

For more information check out these related articles:

Bilateral Tolerance Guide [Examples & Explanation]

What is a bilateral tolerance?

A bilateral tolerance is a plus or minus tolerance (+/-). It allows variation from the nominal size in both a positive and negative direction. 

In most cases, the bilateral tolerance will be specified as equal in both directions such as 10.0mm +/- 0.5mm.

This is not always the case though and a bilateral tolerance does not need to have equal positive and negative tolerances. 10.0mm +0.2mm/-0.3mm would be an acceptable bilateral tolerance as well.

Here are some quick bilateral tolerance examples:

  • 5.5″ +/- 0.25″
  • 5.5″ +1.0″/-0.5″
  • 25.5mm +0.1mm/-0.2mm
  • 30.6mm +/- 0.3mm

Notice that in each of the examples there is allowed variation (tolerance) from the nominal size in both directions.

A tolerance of 25.5mm +0/-0.2mm would not be a bilateral tolerance because it has no tolerance in the positive direction. This would be an example of a unilateral tolerance.

Bilateral tolerance symbol

There is no GD&T symbol for a bilateral tolerance.

Per ASME Y14.5, the notation for a bilateral tolerance is to show a plus and a minus tolerance associated with a nominal dimension and neither of them is a zero.

Want to learn how to type GD&T symbols with no special fonts needed?

How to read a bilateral tolerance

Let’s start with our examples from above

  • 5.5″ +/- 0.25″
  • 5.5″ +1.0″/-0.5″
  • 25.5mm +0.1mm/-0.2mm
  • 30.6mm +/- 0.3mm

Now let’s break it down so you can see what the nominal size is as well as the top and bottom ends of the tolerance zone.

Nominal Size

Bottom of Tolerance

Top of Tolerance

5.5"

5.25"

5.75"

5.5"

5.0"

6.5"

25.5mm

25.3mm

25.6mm

30.6mm

30.3mm

30.9mm

Bilateral tolerance examples

Types of bilateral tolerances

Equal bilateral tolerance

bilateral tolerance blueprint example
An example of an equal bilateral tolerance

An equal bilateral tolerance will have equal plus and minus tolerances such as 6.35 +/- 0.025 as shown in the example above. 

Unequal bilateral tolerance

An example of an unequal bilateral tolerance

An unequal bilateral tolerance will have plus and minus tolerances that are not the same and neither is zero such as 17.0 +0.1/-0.2 as shown in the example above.

Bilateral tolerances compared to other tolerance types

Bilateral tolerance vs unilateral tolerance

A bilateral tolerance allows a tolerance in both directions.

A unilateral tolerance allows a tolerance in only one direction.

A bilateral tolerance is plus AND minus tolerance. A unilateral tolerance is a plus OR minus tolerance.

Here are some examples of unilateral tolerances:

  • 10.0mm +0/+0.5mm
  • 5.515″ +0.010″/+0.015″
  • 2.325″ +0/-0.005″
  • 4.5mm -0.2/-0.3mm

Bilateral tolerance vs limit tolerance

A bilateral tolerance specifies a nominal size and a plus/minus tolerance. These values are used to determine the tolerance range for a feature.

A limit tolerance skips the calculation step and simply gives you the tolerance range.

The table below shows bilateral tolerances with their equivalent limit tolerances.

Bilateral Tolerance

Limit Tolerance

10.0 +/-0.5

9.5 - 10.5

5.525 +0.025/-0.050

5.475 - 5.550

7.55 +/+0.15

7.40 - 7.70

2.324 +0.005/-0.010

2.314 - 2.329

Related articles

Unilateral Tolerance Guide [Examples & Explanation]

What is a unilateral tolerance?

Basically, a unilateral tolerance is a type of tolerance that is only allowed in one direction. Either an all plus tolerance or an all minus tolerance.

Here are some quick unilateral tolerance examples:

  • 10.0mm +0/+0.5mm
  • 5.515″ +0.010″/+0.015″
  • 2.325″ +0/-0.005″
  • 4.5mm -0.2/-0.3mm

Notice that in these examples, all of the allowed size variation is in one direction. The direction can be positive or negative and zero is allowed.

Unilateral tolerances are often used to specify dimensions that require a specific fit with a mating part.

unilateral tolerance blueprint example
Unilateral tolerance shown on a blueprint

Unilateral tolerance symbol

There is no GD&T symbol for a unilateral tolerance.

Per ASME Y14.5, the notation for a unilateral tolerance is to show a plus or a minus tolerance associated with a nominal dimension. It is acceptable for one of the specified tolerances to be zero.

Want to learn how to type GD&T symbols with no special fonts needed?

How to read a unilateral tolerance

Let’s start with our examples from above. 

  • 10.0mm +0/+0.5mm
  • 5.515″ +0.010″/+0.015″
  • 2.325″ +0/-0.005″
  • 4.5mm -0.2/-0.3mm

Now let’s break it down so you can see what the nominal size is as well as the top and bottom ends of the tolerance zone.

Nominal Size

Bottom of Tolerance

Top of Tolerance

10.0mm

10.0mm

10.5mm

5.515"

5.525"

5.530"

2.325"

2.320"

2.325"

4.5mm

4.2mm

4.3mm

Regardless of what the nominal size is, the requirement for each of these unilateral tolerance examples would be that the dimension must fall within the top and bottom tolerance range. 

Unilateral tolerances compared to other tolerance types

Unilateral tolerance vs bilateral tolerance

unilateral tolerance blueprint example
A unilateral tolerance example

A bilateral tolerance allows a tolerance in both directions.

A unilateral tolerance allows a tolerance in only one direction.

A bilateral tolerance is plus AND minus. A unilateral tolerance is a plus OR minus tolerance.

If we take the unilateral tolerance from the picture above and convert it to a bilateral tolerance it could be either:

  • 39.75 +/- 0.25
  • 39.7 +0.3/-0.2
  • 39.6 +0.4/-0.1

Notice that the important feature of the tolerance is that it has both a positive and negative tolerance. Neither side of the tolerance is zero.

Unilateral tolerance vs limit tolerance

A unilateral tolerance specifies a nominal size and a plus or minus tolerance. These values are used to determine the tolerance range for a feature.

A limit tolerance skips the calculation step and simply gives you the tolerance range. Instead of a nominal size and a tolerance, the top and bottom of the tolerance range are directly listed.

Let’s compare some unilateral and limit tolerances to see how they differ:

Unilateral Tolerance

Limit Tolerance

10.0 +0/-0.5

9.5 - 10.0

5.525 +0.025/+0.050

5.550 - 5.575

7.55 +0/+0.15

7.55 - 7.70

2.324 -0.005/-0.010

2.314 - 2.319

What is a unilateral tolerance used for?

A unilateral tolerance is most often used to specify a tolerance associated with a specific fit such as a clearance fit or interference fit.

Related articles

What is a G04 Code? [With Lots of Examples]

The information below is meant for beginners. If you are experienced with CNC programming, then you probably already know this stuff and much more. If you are new to CNC programming, this is the place for you.

Please note that some of the topics below could include more information on the subject. However, in the interest of keeping things simple for those just starting out, they have been left out of this G code guide.

Ready to learn? Let’s go.

Code

G04

Name

Dwell

Description

The machine will stop moving for a set amount of time

What does a G04 code do?

A G04 code makes the cutting tool stop moving for specified amount of time. Following that amount of time the machine will proceed to the next line of code.

When to use a G04 code?

G04 codes are used for multiple reasons. They are used on lathes specifically, to break the chips. This way you don’t end up with one super long, razor-sharp chip.

They are also used to improve surface finishes on both lathes and mills.

What to think about when using a G04 code?

There is some variation to how G04 codes are called out. The difference is how the dwell times are listed.

Depending on what brand/controller your machine is, the following can change:

Letter used in callout to list time

Common letters are F, P, U, and X.

Seconds vs milliseconds

1 second = 1000 milliseconds

Decimal or no decimal

Some controllers require a decimal. Some don’t allow a decimal. Some allow either way but treat the number different based on whether you use the decimal or not. Real standardized stuff ain’t it?

Still, these differences should help you troubleshoot any program issues you have related to a G04 dwell code. Check out the examples below to get a better understanding of how you might see dwell codes on your machine.

I am not experienced enough with all brands of CNC machines. I would like to add a list here that tells the most common ways to callout a G04 command based on the CNC manufacturer.  If anyone has experience with a variety of machines, please leave a comment below and I will make sure to add the info to the post.

4 G04 code examples and descriptions of what they do

Example #1

N005 G04 P3

This is line number 5 of the program.

G04 sets the movement mode as dwell

P3 is the amount of dwell time = 3 seconds.

Example #2

N040 G04 F5.0

This is line number 40 of the program.

G04 sets the movement mode as dwell

F5.0 is the amount of dwell time = 5 seconds.

Example #3

N040 G04 F5

This is the same line as above, on the same controller. The decimal changes how the machine reads the code.

This is line number 040 of the program.

G04 sets the movement mode as dwell

F5 is the amount of dwell time. In this case, 5 milliseconds = .005 seconds.

A big difference. Watch those decimals.

Example #4

N100 G04 U5

This is line number 100 of the program.

G04 sets the movement mode as dwell

U5 is the amount of dwell time = 5 second.

CNC codes that are similar to G04

The table below lists all of the other G codes that control movement like a G04 code does.

What is a G03 Code? [With Lots of Examples]

The information below is meant for beginners. If you are experienced with CNC programming, then you probably already know this stuff and much more. If you are new to CNC programming, this is the place for you.

Please note that some of the topics below could include more information on the subject. However, in the interest of keeping things simple for those just starting out, they have been left out of this G code guide.

Ready to learn? Let’s go.

Code

G03

Name

Circular interpolation, counterclockwise

Type

Modal - stays on until changed

Description

Circular movement at a specified feed rate in a counterclockwise direction

What does a G03 code do?

A G03 code is a circular movement CNC G code. It is used to move the CNC table and/or spindle from its current location to an end location along a specified radius (R) in a counterclockwise direction.

When to use a G03 code?

G03 codes will usually be in the lines of the program that are used to cut the part. The G03 code allows the programmer to cut a full circle or portion of a circle.

F and S codes are used together with a G03 code to specify the feed rate and spindle speed. An R code is used as well to tell the machine what size radius to move along.

What to think about when using a G03 code?

Units

First, make sure you know what units you are working in. Moving 10 inches instead of 10 millimeters is a big difference.

A G20 (inches) or G21 (mm) code should identify the units you are working in before your G03 code.

Absolute vs incremental mode

The second thing to look for is whether you are working in absolute (G90) or incremental (G91) coordinates. The most recent G90 or G91 code in the program will determine which mode you are in.

Absolute coordinates will move from a set zero location such as your machines home location or a specified location on your part.

Incremental coordinates will move relative to your current position. See our posts on G90 and G91 codes to learn more about the differences between absolute and incremental coordinates.

Start and stop locations

Lastly, make sure you understand where you are currently position wise (X, Y & Z location), where you will be moving to and if there is anything in between the two locations.

The G03 code will move the machine in a circular arc to your new location. You don’t want anything in the way or to miscalculate your stop point. Clamps or vises can be easy to forget about and run into. Crashing your machine is never a good time.

3 G03 code examples and descriptions of what they do

For the examples below, we will assume your machine is in absolute mode (G90). If you are working in incremental mode (G91), the resulting movements will be different.

Check out our guides to G90 and G91 G codes to understand the difference between the two movement types.

Example #1

N085 G03 X1.0 Y2.0 R1.0

This is line number 85 of the program.

G03 sets the movement mode as circular, counterclockwise.

X1.0 Y2.0 is the location the machine will move to. There is no Z axis movement in this line.

R1.0 specifies the size of the radius that the machine will move along.

Example #2

N060 G03 X3.5 Y3.5 R0.5

This is line number 60 of the program.

G03 sets the movement mode circular, clockwise.

X3.5 Y3.5 is the location that the machine will move to. There is no Z axis movement in this line.

R0.5 specifies the size of the radius that the machine will move along.

Example #3

N477 G03

This is line number 477 of the program.

G03 sets the movement mode circular, clockwise.

There is no location specified on this line. The machine will not move based on this code line.

CNC codes that are similar to G03

What is a G02 Code? [With Lots of Examples]

The information below is meant for beginners. If you are experienced with CNC programming, then you probably already know this stuff and much more. If you are new to CNC programming, this is the place for you.

Please note that some of the topics below could include more information on the subject. However, in the interest of keeping things simple for those just starting out, they have been left out of this G code guide.

Ready to learn? Let’s go.

Code

G02

Name

Circular interpolation, clockwise

Type

Modal - stays on until changed

Description

Circular movement at a specified feed rate in a clockwise direction

What does a G02 code do?

A G02 code is a circular movement CNC G code. It is used to move the CNC table and/or spindle from its current location to an end location along a specified radius (R) in a clockwise direction.

When to use a G02 code?

G02 codes will usually be in the lines of the program that are used to cut the part. The G02 code allows the programmer to cut a full circle or portion of a circle.

F and S codes are used together with a G02 code to specify the feed rate and spindle speed. An R code is used as well to tell the machine what size radius to move along.

What to think about when using a G02 code?

Units

First, make sure you know what units you are working in. Moving 10 inches instead of 10 millimeters is a big difference. A G20 (inches) or G21 (mm) code should identify the units you are working in before your G02 code.

Absolute vs incremental mode

The second thing to look for is whether you are working in absolute (G90) or incremental (G91) coordinates. The most recent G90 or G91 code in the program will determine which mode you are in.

Absolute coordinates will move from a set zero location such as your machines home location or a specified location on your part.

Incremental coordinates will move relative to your current position. See our posts on G90 and G91 codes to learn more about the differences between absolute and incremental coordinates.

Start and stop locations

Lastly, make sure you understand where you are currently position wise (X, Y & Z location), where you will be moving to and if there is anything in between the two locations.

The G02 code will move the machine in a circular arc to your new location. You don’t want anything in the way or to miscalculate your stop point. Clamps or vises can be easy to forget about and run into. Crashing your machine is never a good time.

3 G02 code examples and descriptions of what they do

For the examples below, we will assume your machine is in absolute mode (G90). If you are working in incremental mode (G91), the resulting movements will be different.

Check out our guides to G90 and G91 G codes to understand the difference between the two movement types.

Example #1

N035 G02 X4.0 Y4.0 R2.0

This is line number 35 of the program.

G02 sets the movement mode as circular, clockwise.

X4.0 Y4.0 is the location the machine will move to. There is no Z axis movement in this line.

R2.0 specifies the size of the radius that the machine will move along.

Example #2

N090 G02 X7.5 Y1.5 R0.5

This is line number 90 of the program.

G02 sets the movement mode as circular, clockwise.

X7.5 Y1.5 is the location that the machine will move to. There is no Z axis movement in this line.

R0.5 specifies the size of the radius that the machine will move along.

Example #3

N250 G02

This is line number 250 of the program.

G02 sets the movement mode as circular, clockwise.

There is no location specified on this line. The machine will not move based on this code line.

CNC codes that are similar to G02

What is a G01 Code? [With Lots of Examples]

The information below is meant for beginners. If you are experienced with CNC programming, then you probably already know this stuff and much more. If you are new to CNC programming, this is the place for you.

Please note that some of the topics below could include more information on the subject. However, in the interest of keeping things simple for those just starting out, they have been left out of this G code guide.

Ready to learn? Let’s go.

Code

G01

Name

Linear movement

Type

Modal - stays on until changed

Description

Straight line movement at a specified feed rate

What does a G01 code do?

A G01 code is a linear movement CNC G code. It is used to move the CNC table and/or spindle.

When to use a G01 code?

G01 codes will usually be in the lines of the program that are used to cut the part. The G01 code allows the programmer to specify where the tool will move to. F and S codes are used together with a G01 code to specify the feed rate and spindle speed.

The location movement, speeds, and feeds are the main factors that influence your cut.

What to think about when using a G01 code?

Units

First, make sure you know what units you are working in. Moving 10 inches instead of 10 millimeters is a big difference. A G20 (inches) or G21 (mm) code should identify the units you are working in before your G01 code.

Absolute vs incremental mode

The second thing to look for is whether you are working in absolute (G90) or incremental (G91) coordinates. The most recent G90 or G91 code in the program will determine which mode you are in.

Absolute coordinates will move from a set zero location such as your machines home location or a specified location on your part.

Incremental coordinates will move relative to your current position. See our posts on G90 and G91 codes to learn more about the differences between absolute and incremental coordinates.

Start and stop locations

Lastly, make sure you understand where you are currently position wise (X, Y & Z location), where you will be moving to and if there is anything in between the two locations.

The G01 code will move the machine in a straight line to your new location. You don’t want anything in the way or to miscalculate your stop point. Clamps or vises can be easy to forget about and run into. Crashing your machine is never a good time.

6 G01 code examples and descriptions of what they do

For the examples below, we will assume your machine is in absolute mode (G90). If you are working in incremental mode (G91), the resulting movements will be different. Check out our guides to G90 and G91 G codes to understand the difference between the two movement types.

Example #1

N015 G01 X7.0 Y5.0 Z3.0

This is line number 15 of the program.

G01 sets the movement mode as linear (straight line).

X7.0 Y5.0 Z3.0 is the location the machine will move to. If the Z location of the machine was already at 3.0, then the Z axis will not move. This is the same for each axis.

Example #2

N070 G01 X6.0 Y2.0

This is line number 70 of the program.

G01 sets the movement mode as linear (straight line).

X6.0 Y2.0 is the location that the machine will move to. The Z axis of the machine will not change and remain at the location it was previously set at.

Example #3

N120 G01 Y2.5 Z1.0

This is line number 120 of the program.

G01 sets the movement mode as linear (straight line).

Y2.5 Z1.0 is the location that the machine will move to. The X axis of the machine will not change and remain at the location it was previously set at.

Example #4

N020 G00 Y4.0

This is line number 20 of the program.

G01 sets the movement mode as linear (straight line).

Y4.0 is the location that the machine will move to. The X and Z axes of the machine will not change and remain at the location they were previously set at.

Example #5

N100 G01

This is line number 100 of the program.

G01 sets the movement mode as linear (straight line).

There is no location specified on this line. The machine will not move based on this code line.

Example #6

N256 G01 X8.0

This is line number 256 of the program.

G01 sets the movement mode as linear (straight line).

X8.0 is the location that the machine will move to. The Y and Z axes of the machine will not change and remain at the location they were previously set at.

CNC codes that are similar to G01

Note that all the movement codes listed below are modal. This means they will stay in the movement mode identified by the code until switched to a different mode.

Micrometers vs Calipers [Similarities, Differences & Everything Else]

micrometer vs caliper

Micrometers and calipers are both precision measuring tools.

The difference between these tools lies in their accuracy and the types of measurements they can take.

Check out the table below for the main differences between the two tools and then keep on reading to gain a better understanding of what those differences mean when it comes time to use them.

Micrometers

Calipers

Accuracy

0.0001"

0.001"

Measuring Range

1" increments

0-6"

Types of Measurements

Outside Measurements

Inside, Outside & Depth Measurements

Micrometer and caliper comparisons

Accuracy

Micrometers are more accurate. 

A typical micrometer is accurate to 0.0001″ and a caliper is only accurate to 0.001″.

This makes a micrometer 10x more accurate than a caliper.

Just keep in mind that you can buy cheap versions of both tools that have worse accuracy. Also, if you were to buy a larger versions of these tools they will often have lower accuracy. 

A 17-18″ micrometer might only be accurate to +/- 0.0002″ and a 0-24″ caliper may only be accurate to +/- 0.002″.

To sum it up, realize that there is some variation in accuracy but in general you will find that micrometers are 10x more accurate than calipers.

Measuring range

starrett micrometer set in case with reference standards
0-6" Micrometer set

Micrometers come with 1″ measuring ranges. 0-1″, 1-2″, 2-3″ and so on. 

The most common measuring calipers measure over a 0-6″ range. Larger varieties can be also be found with 0-12″ and 0-24″ measuring ranges. There are some different ranges available such as 0-4″ and 0-8″ also but they are much less common.

This difference in measuring ranges means that you would need a set of micrometers to measure over the same measuring range a single caliper is capable of. 

Calipers have larger measuring ranges but they are less accurate.

Types of measurements they are capable of

Caliper measuring internal hole
caliper depth base attachment
Depth measuring rod extended from caliper - depth base attachment shown

Most calipers will measure inside, outside and depth measurements. 

digital caliper measuring coin
Standard outside diameter being measure with digital caliper

Micrometers are capable of only performing one type of measurement. 

The most common type of micrometer is an outside micrometer, usually referred to as simply micrometers or sometimes mics.

anytime tools 1-2" micrometer
0-1" outside micrometer

Inside micrometers and depth micrometers are also available to take internal and depth  measurements.

Calipers are capable of taking a much larger variety of measurements.

Depth micrometer with multiple rods for different size measurements
mitutoyo inside micrometer set
Inside micrometer with multiple attachements for different size measurements

Ease of use

To maintain the added accuracy that a micrometer has requires taking more care when using them. 

Something as small as the amount of force you use to close the micrometer can change your measurement. Many micrometers will have ratchet or friction stops that help alleviate this problem. 

When you are working down to a tenth (machinist lingo for 0.0001″), even temperature comes into play. Metals expand and contract with changes in temperature. To protect against this, most micrometers have plastic pieces that can be used to help insulate your from the tool.

outside micrometer
0-1" outside micrometer with piece of black plastic for thermal insulation

A good micrometer stand can help keep you accurate as well.

The same factors affect the accuracy of a caliper but the effects aren’t as noticeable because they aren’t as accurate.

Speed

Calipers are quicker to use than micrometers. The jaws can open and close in a split second.

Micrometers need to spin the thimble around 40 times to cover an inch of travel. 

Cost comparison

A micrometer and a set of calipers have similar price points. Take for example a 0-1″ micrometer from Mitutoyo and a 0-6″ set of calipers from Mitutoyo.

The difference would be that to cover the same measuring range of a set of calipers, you would need a 0-6″ set of micrometers. A good set of micrometers is going to cost quite a bit more than your typical 0-6″ caliper.

More info about micrometers and calipers

Parts of a micrometer

parts of a micrometer

The part being measured will be placed between the anvil and spindle of the micrometer. The spindle is adjusted in and out by turning the thimble clockwise or counterclockwise. 

Depending on the micrometer being used, the lock nut, lock ring or lock lever can be used to hold the micrometer at a specific size. Some tools will not have any locking feature. 

Measurements are read using the scales on the sleeve and thimble. 

The frame of the micrometer can vary across brands and types of micrometers. Some are made specifically to have smaller frames for different measuring applications. 

Many micrometers also have a ratchet stop or friction stop that limits the amount of force applied to the thimble. This allows more consistent measurements.

Parts of a caliper

The jaws for external measurements are used to measure features such as length, width and thickness.

The jaws for internal measurement are used for measuring features such as hole sizes and slot or groove widths.

The rod for depth measurements is used for measuring depths of holes, counterbores and step heights. 

The scale and dial indicator face are used together to obtain measurement readings.

The slide of the caliper which consists of the moveable jaws along with the dial indicator face are slid along the beam.

The lock screw can be used to hold the caliper at a specific size for repetitive measurements.

Digital vs analog micrometers

Digital micrometers are great for the speed at which measurements can be read. Their display means very little training for the operator. 

Another benefit of a digital micrometer is how quickly measurement values can be converted between inch and metric readings. A simple button press can save time and do the conversion for you. 

starrett 0-1" micrometer
Starrett analog micrometer
mitutoyo digital micrometer
Mitutoyo digital micrometer

The downfall is that they tend to be quite a bit more expensive than a standard analog micrometer and they are more susceptible to contaminants such as water and coolant. Some models are offered with resistance or protection from different contaminants. 

In recent years, prices have dropped for digital micrometers making them more affordable. 

Analog micrometers tend to be a very dependable tool and many have been in use for generations. This also means that there are many used options on the market for analog micrometers. 

If cost is your primary concern, I recommend going with an analog micrometer. If ease of use and operation is important then go with a digital micrometer.

Digital vs dial vs vernier calipers

mitutoyo 6 inch vernier caliper
Mitutoyo vernier caliper

Vernier calipers are the most resilient type of calipers. They will be the least affected by things such as dirt and water or coolant. Unfortunately they are the most difficult to take measurements with. Learning to read the scales takes some practice. 

Dial calipers are a good middle ground with measurements that are relatively easy to take with the dial indicator face. They are reasonably resistant to contamination though they should still be handled with care. 

anytime tools dial caliper dial face
Dial caliper

Digital calipers are by far the easiest to use. The LCD display takes any guesswork out of reading your measurement. They are also the most susceptible to damage from things such as dirt and coolant. 

Unless they are being used in the harshest environment, I recommend getting digital calipers. Digital calipers can be purchased with ingress protection if needed.

Summary

While they are both precision measuring tools, there are some key differences between micrometers and calipers. 

Micrometers are more specialized and have a smaller measuring range. As a result they are generally more accurate and often capable of measurements to .0001″. 

Calipers are more versatile. They have a much larger measuring range. To achieve this they sacrifice accuracy and most often take measurements to an accuracy of .001″. 

As you can see they both have their strengths and weaknesses but in the end they are two of the most important precision measuring tools you can have in your toolbox.