Best Woods For CNC Routing

cnc router engraving design

Let’s say you have some extra time on your hands, and you decide to build your own computer. Countless people do this every year, so surely it can’t be too difficult to find the necessary materials, right?

Then you realize you’re going to need some basic electrical wiring. Would you go search through a pile of old electronics and rip out whatever you can find?

Of course not.

You’re going to go find something that is meant for your build.

The same goes for CNC routing. You can’t (or at least shouldn’t) use just any old piece of wood you see lying around.

To build a nice project, you’ll need quality material, and we are going to help you figure out which ones are right for your use. Picking the right wood is especially important when you are making things to sell with your CNC

We do our best to run through as many different types of wood for CNC routing that we could come up with, but if you just want the short and sweet version to help you pick a wood to work with check out our list of the best woods below.

Category

Wood Type

Easiest wood for CNC routing (best for beginners)

Cherry

Best wood for CNC carving

Walnut

Best wood for CNC sign making

Cypress

Best cheap wood for CNC routing

Poplar

Best plywood for CNC routing

Birch

Below is a lengthy list of various types of woods that you can use for CNC woodworking.

While the list may not include absolutely every type of wood you might want to use, it does hit the main ones

The cost of the different woods will vary by region and availability, but we have tried our best to assign a relative cost score to them.

Cost rating system

Keep it simple right? We used a scale of 1-5 dollar signs

$ = cheaper woods

$$$$$ = very expensive woods

Alder

Cost: $

Alder wood is generally light and soft. Its structure is even with straight fibers. Highly pliant, alder wood is one of the preferred woods for furniture makers the world over.

Alder is pretty good for carving, though it can be a bit stringy at times.

Ash

Cost: $

Ash wood is strong, durable and generally light in color. It is coarse, but the grain is fairly straight. As a result of its strength and durability, ash wood has an array of uses but is commonly used in the making of tools, furniture and frames.

For routing, you might find moderate resistance with ash because it’s a stronger wood. Ash can tend to wear your cutters quicker than other, softer woods. If you’re going to use ash, make sure your cutters are sharp before you start.

Balsa

Cost: $

Balsa is the lightest and softest timber used commercially. Though it’s lightweight, balsa is also fairly coarse. It possesses an unusually high degree of buoyancy, and the wood is adaptable to a great number of special uses.

If you’re using softer balsa, it can be prone to tearing along the grain as the cutter goes past. It can also be hard to get a nicely finished edge with balsa.

Beech

Cost: $

Beech wood is known for its fine-textured straight and attractive grain, pliability, strength, and finishing ease. However, Beech wood has a fairly high shrinkage rate, which is why most beech wood ends up as paper.

When routing beech, you’ll likely want to have the router moving at a lower speed to avoid burning.

Birch

birch wood grain

Cost: $

Birch is a stiff wood with light color and wavy grain.

When working with birch, you should go slow and take shallow passes. If routing in one direction causes a lot of splintering, turn the board around and go in the opposite direction. This hits the grain from a different direction. The splintering is caused by the bit digging into the grain. Going the other way stops that.

Birch plywood

Cost: $

For birch plywood, some good advice is to cut the chip load down to about half of what you would normally do.

You should also have your spindle speed as high as you can get it without overheating the cutting tool. For engraving, you will find that it is best to outline the toolpath first.

Cedar

cedar wood grain

Cost: $$

Cedar has a nice smell and good color, but the knots in the wood can make it a bit difficult to work with.

Also, because it’s a softer wood, you need to be careful with tear outs – this is a common problem with cedar. To avoid the tear-out issue, try doing multiple passes.

There are some who swear by soaking and freezing cedar before working with it as a way to get a better finished product.

Cherry

Cost: $$$$

Cherry wood is hard, durable, resistant to rot and decay, and has a pretty good ability to withstand shock.

It’s also easy to carve, cut, and mold.

Cherry is interesting because it is a relatively soft hardwood.

In other words, cherry wood is a fantastic option for CNC wood routing, and you’ll find that it is popular among hobbyists and professionals alike. Cherry has a reputation for being easy to work with due to its versatility.

Cyprus

Cost: $

Cypress wood is extremely soft, and a lot of woodworkers will tell you that this stuff carves like butter.

Cypress is a really great option if you’re looking at making signs. Cypress also holds up extremely well outdoors. It is a decay-resistant wood.

One downside to cypress would be that it can be a knotty wood, similar to cedar.

In other words, cherry wood is a fantastic option for CNC wood routing, and you’ll find that it is popular among hobbyists and professionals alike. Cherry has a reputation for being easy to work with due to its versatility.

Elm

Cost: $$$

Elm wood has fairly open pores, which can lead to a lot of tear-outs if you’re not careful.

Some people also find Elm to be a bit stringy. However, elm is also known for being extremely tough, so if you can avoid tear-outs and your project isn’t too stringy, you will have your elm wood project for a long time to come.

Elm is a little pricier now than it used to be because “Dutch Elm Disease” wiped out a good portion of elms around the world.

Fir

Cost: $$

Fir has a nice consistent pattern and is pretty easy to work with.

Fir can have some issues with tear-outs, but most people can easily avoid these through climb cuts. Though Fir can splinter a bit, it isn’t known for having knots, which makes it easier to work with.

Mahogany

Cost: $$$$$

Many woodworkers the world over will consider genuine mahogany to be the best wood on the market.

It’s durable, stable, and looks beautiful. It’s a fairly hardwood but is easy to work with. Its mostly straight, open grains mean the wood rarely tears out.

When working with mahogany, you should go a bit slower in terms of your feeding, and don’t overload your carvers.

Maple

maple wood grain

Cost: $$$$$

If you don’t have a ton of experience, maple can be a little bit difficult to work with.

The wood is extremely hard, so you’ll need very sharp cutters, though the maple will dull them while cutting.

You should also cut at a lower speed to prevent any burning. Though maple might be hard to work with, you’ll love the final product because it’s a beautiful wood.

MDF

Cost: $

Medium-density fiberboard is super cheap and versatile. MDF is basically sawdust and glue, so be prepared for a sandstorm when you’re working with it.

Still, people find MDF super easy to work with as it carves and cuts extremely easily.

Oak

red oak wood grain

Cost: $$$$

Oak is a heavy, hard wood that rarely breaks. Since it’s so hard, you want to be a little careful when it comes to cutting.

Make smaller passes, and take multiple passes, so you don’t break any of your bits. Also, watch out for any burning.

Paduak

Cost: $$$

You’ll really like the way padauk carves but be sure to bring a sharp bit. The reason people like to work with Padauk is that it has nice, straight grains.

One thing to watch out for when working with Padauk is the dust. When you start cutting this wood, you’ll get a lot of dust, so you might find a dust boot helpful.

Pine

pine wood grain

Cost: $

Pine generally machines well, but sometimes certain cuts can get a little bit gummy on you.

Another thing about pine is that it’s a fuzzy wood, so it can be helpful to sand the wood down both before and after you work with it.

Making multiple passes can also reduce some of the fuzz. Pine may not be your first choice to work with, but you should learn how to machine pine because it’s reasonably cheap and available everywhere.

Pine plywood

Cost: $

Like with regular pine, again get a lot of fuzz. The benefit here, though, is that this stuff is so easy to find and it’s cheap.

Be sure not to cut too deep and take multiple passes when working with pine plywood. Patience will be key if you want the project to turn out well.

Poplar

poplar wood grain

Cost: $

Similar to pine, Poplar is widely available, cheap, and leaves behind a lot of fuzz.

So, like with Pine, be sure to sand the Poplar down well. You will also want to have sharp bits and a slower speeds and feeds to avoid any tearing.

Poplar will take paint really well, so if you’re working on a project that you’ll ultimately want to paint poplar might be your choice of wood.

Red gum

Cost: $$$

Due to its softness and low density, people generally find red gum easy to work with.

However, red gum does have interlocked fibers, so be careful to avoid tear-outs. Another criticism of red gum is that it can warp a lot when drying out.

Redwood

Cost: $$$

While Redwood is light but strong, it does splinter fairly easily. Make sure you’re using shallow cuts to avoid tear-outs.

If you’re just looking for a carving project, redwood will be fantastic due to its softness.

Spruce

Cost: $

Spruce is not really known for being great wood to route with. It splinters easily and can have hidden sap pockets that can’t be cut through and will make your bit super sticky.

With short fibers and many knots, you may find it difficult to work with spruce.

Walnut

Cost: $$$$

Walnut is a very popular wood when it comes to routing. It cuts well. If you have a sharp bit, then cutting through walnut is like passing a hot knife through butter.

Another great feature of walnut is that it is not really known to burn while routing. However, Walnut dust can be highly irritating, so be sure to protect your eyes. A dust collection system of some sort would be advised.

Western red cedar

Cost: $$$

Western red cedar has a really wide grain which can be helpful for routing. That said, this wood can easily tear out if you’re not careful. This red cedar can be a better option than regular cedar because it has fewer knots.

Another benefit of red cedar is that it is good to use for outdoor projects.

Yew

Cost: $$$$

Yew can be a tough wood to work with. For one, when yew trees grow, they can contort in a way to that creates a lot of cross-fibers, which can lead to tear-outs.

Additionally, Yew wood can come with a whole lot of knots that you’ll have to work around.

Things to consider when choosing your wood for CNC routing

Clean up

Some woods that create more fuzz – such as pine and poplar – are going to require additional sanding. You can’t just pull these woods off the machine and expect a finished product.

Other woods may not have fuzz, but the cutting action will create rough edges that have to be sanded out. Keep this in mind when creating a project timeline.

Additionally, some of these woods are heavy on the dust. All of the woods listed will create some dust, but some woods are worse than others. You’ll definitely need a shop vac or other form of dust collection in use, and it could be very helpful to have a dust boot.

Knots

A knot is a portion of a branch or limb that has become incorporated in the trunk of a tree. Knots can change the direction of the wood, which make the wood vulnerable to tear-outs.

Your machining parameters should be reduced when working with a knotted portion of the workpiece to avoid shock loading.

Before you can machine them, use 5-minute epoxy to lock loose and loosening knots into place and fill any gaps and voids. When the epoxy cures, you can saw, joint, or plane the wood without fear of knocking the knot out, or worse, sending it flying across the shop or hurting you or your machine.

Price

Depending on what wood you use, your project can skyrocket up in price.

The more exotic woods you use, the more expensive they will be.

Redwood, for example, only grows in a very specific location and environment, so that makes it rarer. Pine, on the other hand, is easily available so it’s cheap.

Expensive woods can be worth it if you’re making a nice project, but don’t spend a bunch of money on wood if you’re not sure how the project will turn out. It is best to practice with the cheap stuff until you get things more figured out.

When you do start moving up to more expensive woods, run some test cuts or small test projects to try out your setup before committing to a large project.

Where to buy wood for CNC routing

You can go to your local hardware store to check out their wood selection. Some stores will have scrap or damaged pcs that can be had for free or at a large discount.

This can be a good way to get material for a small project or for testing out cuts on different types of wood.

You can also find a lumber mill near you and see if they’ll sell you any wood. Oftentimes, lumber mills will have excess wood that they can’t use that they will sell you for cheap.

Break Edge – All About

What is a break edge?

break edge blueprint examples

A break edge means the removal of material, usually in the form of a chamfer or radius to remove the sharp edge.

Machining a surface will often leave a corner which can be dangerous for both the part and the part handler. Many times there will be a burr (raised piece of material), left on the edge which can be razor sharp. Using a deburring tool can break the edge to remove the sharp 

A broken edge is usually specified as a maximum value or with no value at all. If no value is specified, the break edge has not been constrained sufficiently.

A break edge callout with no maximum size referenced would normally be assumed to be approximately .005-.010” though in some instances it could be larger.

What does a break edge look like?

Break edge on a physical part

In the brass cube below, notice how the corners have all the sharp edges removed. This is an example of a break edge.

metal cube with break edge

Break edge on a blueprint

Break edge symbol

There is no GD&T symbol for a break edge. Break edges are also not referenced in the engineering drawing standard ASME Y14.5.

Break edge callouts are specified directly on the drawing to reference a certain surface or as a note e.g. “Break all sharp edges”.

At times, the break edge specification may be contained in the general tolerance block such as shown below.

Break edge note example

general break edge note on blueprint
Break edge note example

How to make a break edge

Break edge on wood

Using 180 grit fine sandpaper is the easiest way to create a break edge on a wooden workpiece. This can also be used together with a block plane to chamfer the edge and then soften it with a light sanding.

Break edge on metal

Because metal tends to be more durable, you have more choices for creating a break edge on your piece of metal.

You can use:

  • A chamfer deburring tool which is a specialty tool designed to remove burrs from the edges of parts
  • A file to knock the edge off a part
  • Sandpaper
  • A grinding wheel
  • A rotary tool such as a Dremel

Break edge on glass

To create a break edge on a piece of glass, use one of the following:

  • Diamond file
  • Grinding wheel
  • Rotary tool with diamond wheel

How to measure a break edge

Which measuring tools to use

igaging pocket comparator with reticles and case
A pocket comparator with various reticles for measuring

The size of a break edge is measured the same as a standard chamfer or radius. If a measurement is required, a pocket comparator or eye loupe with a reticle are the most common inspection tools to use. 

An optical comparator with or without an overlay could also be used. See the examples below to better understand how the size of a break edge would be determined.

How to measure the break edge based on your blueprint

break edge examples

On the left is a chamfered break edge. The size is measured from the left edge of the part to the intersection of the break edge and the top of the part. This is done in both the x and y directions (up and down, left and right). 

On the right is a break edge created by a radius. The same measurement technique applies with the exception that the intersection would now be called the tangent point or point where the radius meets the straight edge.

Break edge compared to similar features

Break edge vs chamfer

The difference between a break edge dimension and a chamfer dimension is generally in the tolerancing of the two. A chamfer is usually thought of as being toleranced in a way that places tighter constraints on the feature. 

Often a chamfer callout will have a tolerance associated with the angle and a break edge will not.

Break edge vs radius

A break edge can be a radius. Many times, the person or company machining the part will round the edge using a variety of techniques including tumbling, specialty tools or even sandpaper.

Want to learn more?

GD&T is a complicated subject and understanding it correctly can be the difference between a perfect part and scrap.

The best way to learn GD&T is from experienced teachers who can break down the material into manageable pieces.

Luckily, we know someone.

And MachinistGuides.com readers get an exclusive discount on training!

Measuring Calipers

Prices have dropped significantly in recent years meaning that many digital calipers are directly competing with your standard dial calipers. Find out which ones are the best of the best as well as check out our tips, tricks and calibration guides.

People have been taking precision measurement with dial calipers for decades. So why stop now? Check out our guide to dial calipers to figure out which ones are quality and which ones are just over priced. Lots of extra info so there is something for everyone.

Analog vs Digital

Old School vs New School

Which caliper comes out on top and why? Read out comparison guide to find out.

Learn how to get the most accuracy possible out of your caliper.

Includes comparisons of different caliper types and guidance for figuring which one is right for you.

There are a lot of digital calipers out there and let me tell you, they are not created equal. Find out which ones are best in class and which ones belong in the trash.

Just starting out? Then check out our Beginner’s Guide to Calipers – Dial and Digital to kick start you knowledge and get you headed in the right direction.

Standard Micrometers

Find the very best mics out there. Includes picks for great analog and digital micrometers. Guidance for finding good used micrometers as well!

Learn how to calibrate your own tools using our simple step by step guide. Includes guidance for calibration frequency and real world calibration advice.

Two incredibly useful measuring tools with some key differences. Find out what makes each piece of precision measuring equipment special. Includes tips for figuring out whether you need one or the other, or maybe both.

When it comes to micrometers, some of these manufacturers have been making tools for an extremely long time. Like 100 years or more. Find out which ones have been consistently the best so you can spot a great flea market find.

Micrometers are wonderful tools but they have their limitations. One of those limitations is the small measuring range, so if you want to measure with extreme accuracy across a wide variety of sizes then you’re gonna need a set. Find out which ones top our list. You just might be surprised.

Reference Dimensions [Guidance and Examples]

What is a reference dimension?

single reference dimension

A reference dimension is just what it sounds like. It is a dimension shown for reference. In other words it is there for informational purposes only.

They are not a requirement in any way.

Reference dimensions can be used to clarify other dimensions on a drawing. In some instances, they make a drawing easier to understand.

Reference dimensions on blueprints

How are reference dimensions shown on a drawing?

There is no GD&T symbol for a reference dimension. Reference dimensions are shown on a drawing as a value enclosed in parentheses.

An alternate method is to follow the dimension with “Reference” or “Ref”. The use of “Ref” or enclosing the dimension inside parentheses are by far the most common notations used. These notations are specified in ASME Y14.5 the Dimensioning and Tolerancing standard.

When to use a reference dimension

Reference dimensions are useful for clarification purposes. Their inclusion can make it clear how another dimension should be inspected or manufactured.

At other times they are included to make the drawing easier to read. It isn’t always immediately clear what a part looks like by looking at the blueprint.

A very common use of reference dimensions is to provide a conversion of the length units of the drawing from either metric to inches or vice versa.

Watch out for these conversions! Too often they are rounded excessively and not accurate. Reference dimensions should never be used for acceptance..

Reference dimension examples

reference dimensions

These examples show some of the variety you might see on your blueprints to call out reference dimensions.

Reference dimension measurement

Do reference dimensions have tolerances?

Reference dimensions do not have tolerances. Additionally, the general tolerances you find in a tolerance block do not apply to them.

Are reference dimensions measured?

Reference dimensions can be measured and the results recorded but this is not a requirement. Often reference dimensions will be recorded more as a note.

Reference dimension vs basic dimension

Reference Dimensions

Basic Dimensions

Shown in parentheses or with Ref notation

Shown enclosed in a box

Informational only

Controlled by another tolerance (GD&T)

Do not need to be measured or recorded

Will need to be measured for calculation

Basic dimensions are used in GD&T tolerancing. associated with another tolerance or dimension.

While they don’t have a tolerance tied to themselves, they are used to calculate the tolerance of another feature such as the true position of a hole. If the location of a hole was controlled by basic dimensions, you would never reject it for the hole location but instead for violating a GD&T requirement such as true position.

In other words, basic dimensions don’t have their own +/- tolerance but they are controlled by a different tolerance requirement.

single reference dimension
An example of a reference dimension
basic dimension example
An example of a basic dimension

Reference dimensions do not have a +/- tolerance and are not controlled by another requirement. They have no tolerance associated with them. No matter how far off the given value a reference dimension is, it would never be cause for rejection.

A basic dimension being far off its nominal value would not be cause for rejection itself, but its effect on another feature referencing the basic dimension could be cause for rejection.

Basic dimensions are identified with a rectangular frame around them such as in the example below.

Want to learn more?

GD&T is a complicated subject and understanding it correctly can be the difference between a perfect part and scrap.

The best way to learn GD&T is from experienced teachers who can break down the material into manageable pieces.

Luckily, we know someone.

And MachinistGuides.com readers get an exclusive discount on training!

Measuring Tool Calibration Guides

If your measuring device isn’t reading correctly then it might as well be useless.

But how do you know if you can trust that your tool is accurate?

Check the calibration of course!

And you check the calibration by checking our guides to calibrating your precision measuring tools below.

Micrometers are one of the most accurate tools many people will ever use. Keep them in tip top shape by calibrating them regularly.

Digital Caliper Calibration

Calipers are capable of many types of measurements. Digital calipers make those measurements easy to read. Our guide makes calibrating easy to do.

Dial Caliper Calibration

We get it, some like to kick it old school. Well, we’ve got you covered with our complete guide to calibrating your dial calipers.

Types of Tolerances Used On Blueprints [With Examples]

There are many different ways to specify tolerances on an engineering drawing. 

These tolerance types are shown below and include multiple examples for each tolerance type. 

Take note that the geometric tolerancing covers a wide variety of tolerancing applications. Follow the links in that section to go more in depth.

bilateral tolerance blueprint example
Bilateral tolerance example

Bilateral tolerances allow a plus or minus deviation from the nominal size.

In most instances, the plus/minus tolerances are equal but this is not a requirement.

Bilateral tolerances can be uneven. For example, a tolerance of +0.1/-0.2 is a bilateral. +/- 0.1 is also bilateral.

Bilateral tolerance examples:

  • 10.5 +0.2/-0.2
  • 10.5 +0.2/-0.1
  • 10.5 +/- 0.5
unilateral tolerance blueprint example
Unilateral tolerance example

Unilateral tolerances allow variation in only one direction. This can be in either a positive or negative direction.

Some unilateral tolerance examples are:

  • 10.5 +0/-0.5
  • 10.5 -0.1/-0.5
  • 10.5 +0.4/+0
  • 10.5 +0.1/+1.1
limit tolerance example
Limit tolerance example

Limit tolerances directly specify the upper and lower limits of the tolerance. The feature size must fall within these limits.

Limit tolerance examples:

  • 10.5/10.7
  • 10.5-11.0
feature control frame description with parts identified
A feature control frame

GD&T Tolerancing

Geometric tolerancing with GD&T allows greater control over the the tolerances themselves. 

GD&T tolerances are able to control form, orientation, size and location. 

For more information on geometric tolerancing, see our posts on basic dimensions, datums, feature control frames, and blueprint symbols.

Want to learn more?

GD&T is a complicated subject and understanding it correctly can be the difference between a perfect part and scrap.

The best way to learn GD&T is from experienced teachers who can break down the material into manageable pieces.

Luckily, we know someone.

And MachinistGuides.com readers get an exclusive discount on training!

37 Different Tools for Measuring Length

wooden ruler for measuring length sitting on desk

The world is full of amazing measurement tools. Some you might not even think about even though they are all around you.

Our list covers everything from common length measuring equipment to super expensive devices that use lasers to calculate distance and everything in between. If you need to size up something in your life, then check out the comprehensive list below.

Household length measuring tools

I got one, you got one. We all got one. These length measuring tools can be found in many homes around the world. If you are looking for something more exotic, stick around because we saved the weird stuff for last.

Ruler

wooden ruler for measuring length sitting on desk

Everyone knows this one. It is one of the first measuring tools that kids learn to use in school. Most come in a 12” length.

They are made of different materials including plastic, wood, and metal. The steel rule is another name commonly used to describe a metal ruler. There are also other rulers used in certain trades which we have listed below in our Specialty Length Measuring Tools Section.

Yard stick

A preferred measuring tool for crafters and anyone working with fabrics. You’ll never guess how long this measuring tool is.

Side note: They also make an excellent wooden weapon in the event of sudden swordplay.

Folding rule

Somewhere between a ruler and a tape measure. They are not nearly as common as they were decades ago.

The folding rule has largely been replaced by your typical tape measure, but are still a favorite of many woodworkers.

folding rule and tape measure

Tape measure

A common, everyday construction tool. Check your junk drawer. You probably have one already. They come with different measuring ranges. The most measuring ranges measure up to 10-30 feet.

Measuring tape

folded measuring tape

I bet we just confused the dyslexics. Measuring tapes are used for measuring body parts as well as other contoured shapes. They are used in the sewing and tailoring industries primarily.

Some call them flexible rulers instead.

Pedometer

pedometer

Fitness trackers such as those from Fitbit or Garmin that keep track of all the steps you take. They combine it with your stride length (based on your height) to tell you how far you traveled on foot.

Odometer

odometer measuring miles travelled

Are we there yet? Odometers measure the distance that your car has travelled. Take a short trip and figure out how far it is to the grocery store or check the total distance your car has travelled in its lifetime.

Precision length measuring tools

Not your everyday tools. These length measuring instruments measure things with extreme accuracy. Some you can find at your local Walmart while others cost so much if you want one, you’re going to need a few more full-time jobs.

Micrometer

outside micrometer

Used by machinists and mechanics alike, micrometers are extremely precise length measuring tools. They come in many different types such as inside, outside and depth micrometers. Most will measure accurately to .0001”. That’s really small.

Like a human hair divided by 30! The only catch is that most micrometers can only measure over a 1” range.

Dial caliper

Starrett 3202-6 0-6" dial caliper

Unlike micrometers, dial calipers are a little more versatile. They can’t measure as accurately but they can do more. Most calipers are capable of measuring inside, outside and depth measurements all with the same tool.

They have about 1/10 the accuracy but that is still extremely precise for most uses.

Gauge block

gauge block set

Gauge blocks are a tool used for comparison measurements of length. They get stacked up and another tool such as a test indicator is used to compare the two lengths.

They are reference standards for length measurements. Many come in stainless steel but different materials such as ceramics are available too.

Feeler/thickness gauge

They check the length of small gaps. Feeler gauges are used in engine repair and the machine trades.

The different size gages in the set get placed into the gap until there is resistance or the next size won’t fit. They get used in tight spots where other measuring devices can’t fit.

Dial indicator

dial indicator

Different indicators have different measuring ranges. While they can be more accurate than a micrometer, they usually have an even smaller measuring range. They typically can only take measurements over a fraction of an inch.

They can be setup at different distances which allows them to be more versatile by taking comparison measurements relative to a standard such as the gauge blocks we just mentioned.

Pocket comparator

eye loupe

Sometimes called an eye loupe, or jeweler’s loupe, these optical measuring tools come with a reticle in the eyepiece that allows them to measure the length of small objects such as gems.

Their magnification and versatility allow them to measure a wide variety of shapes and sizes.

Dial snap gauge

These length measuring gauges allow the user to get fast, repeatable measurements of a variety of features. Typically, they will get set to zero at a desired length and then parts will be measured against the nominal desired size.

Speed is the name of the game here and this gauge does it in a snap.

Height gauge

Height gauges are used to measure distances from a reference point such as a surface plate. Not only used for heights, but the parts can also be twisted and turned to measure length, widths and depths as well.

Height gauges are a versatile tool for measuring a variety of features.

Depth gauge

This tool gets used for many different measurements. Most often they are used in woodworking to setup saws and routers. Their unique shape allows them to take measurements that would be more difficult with other tools.

Optical flat

This one only works when you have something very flat. The optical flat gets placed on the part to be measured and the light creates a pattern of interference rings that can be counted to tell you how far apart your highest and lowest point on the part are.

These can be expensive, so you probably don’t have one in your junk drawer. Or maybe you do. I don’t know how many millionaire retired optical engineers might read this.

Gauge pins

gauge pin set

Remember Goldilocks and the three bears? Gauge pins work like that. You keep trying them until the next one doesn’t work and this way you know which one is “just right”.

It’s a game of trial and error but you usually have an idea of where to start your measurements. Gauge pins come in sets with each one having 50-250 pins on average.

Microscope

microscope

Like a less portable version of the pocket comparator. Microscopes tend to be extremely accurate. They get used for measuring small parts as well as used in scientific applications. You can expect to find them in many industries including healthcare operations, jewelry stores and machine shops.

Dial bore gauge

fowler dial bore gage set in case

Dial bore gauges accurately measure hole sizes and other internal features. They are dial indicators with a special measuring attachment that allows them to take readings in otherwise unreachable locations

Electronic length measuring tools

Who doesn’t like electricity? These linear measuring tools consist of some of the most advanced measuring technology available.

Interferometer

They are the digital version of an optical flat. They are way more accurate and also way more expensive. It is pretty neat to measure something in waves of light but most won’t want to take a second mortgage on their home and sell their most well behaved child to be able to make it happen.

Electronic indicator

Electronic indicators work on the same measuring principle of dial indicators. Often, they are more accurate and are capable of things like switching between measuring units at the press of a button.

You can find many examples that will measure down to a millionth of an inch!

CMM

cmm measuring part

A CNC inspection machine capable of measuring length, width, thickness, and a variety of other attributes at the push of a button. An expensive and highly capable measuring tool.

Just set it up and press go. The CMM can then check dozens or even hundreds of measurements on dozens or even hundreds of parts. Because they are so automated, an experienced user can run multiple machines at once and really get some work done (aka browsing the internet on their phone).

Optical comparator

A shadow measuring machine. You place your part between the light and some lenses and presto, you get a shadow image.

The cool thing about optical comparators is that the shadow can be measured to determine all kinds of sizes such as length, width, thickness, etc.

Digital micrometer

mitutoyo digital micrometer

An electronic version of a normal micrometer. They come in a variety of types including digital outside and depth micrometers. Digital micrometers make it easier to read your measurements because they don’t require using the vernier scale that is used on a normal micrometer.

Digital caliper

mitutoyo digital caliper

Digital calipers measure the same things as a normal caliper. Instead of a dial face or vernier scale, they have an LCD display. One nice feature is that most can switch between metric and imperial units at the push of a button. Some will even do fractions which is a nice bonus for anyone doing woodworking.

Rangefinder

A rangefinder is a distance-measuring device used to determine the distance from the user to a target.

Aim the rangefinder at a target and press a button to send an electronic pulse toward the target. The time between sending the pulse and receiving the bounce back determines the distance to the target.

Laser measuring tool

Bosch GLM 50 laser measuring tool

Laser measuring tools are very similar to rangefinders but are used over shorter distances where accuracy is more important. Rangefinders get used to measure distances outside and often laser measuring tools are used around the house or nearby.

GPS

GPS app on smartphone

GPS receivers receive signals from satellites (at least 3) and use them to calculate the GPS units exact position on Earth.

A GPS device such as your phone can also communicate with other devices, telling them where it is and how fast it’s moving. GPS can even be used to determine how far away from your house the pizza delivery driver is.

Machine vision systems

A relatively new invention, machine vision systems use cameras to measure distances and features optically. Something like an automated CNC microscope and they do it all without ever touching the things they measure.

Radar

Radar is a system that uses radio waves to detect and locate objects such as ships, aircraft, and even snowstorms. Radar can even detect, locate, and track objects through rain, snow, fog and other bad weather conditions.

Fun fact: radar is one of the most successful inventions in modern history because it has drastically reduced the number of casualties in warfare and regularly saves people from weather related disasters.

Specialty length measuring tools

Oh, I see! You’re looking for the weird stuff. Well, the tools below fit the bill. It’s easy to see why you might use a ruler or tape measure but these length measuring instruments are a little more different.

Surveyor's wheel

A great alternative to a Fitbit. Just push this measuring wheel around all day and you’ll easily know how far you have traveled. People will think your strange but just tell them you are “eccentric”.

Architects scale

architects scale and pencil

Don’t tell the architects but it’s just a fancy ruler. I bet they paid extra for the name.

An architect’s scale has more precise markings than a standard ruler and comes in a triangular shape which does something. I don’t know what, but building designers love it!

Paint thickness gauge

It’s almost like magic! A paint thickness gauge can measure the thickness of your car paint or other coatings through the use of a magnetic current. They find use in auto body shops and manufacturing facilities throughout the world.

Tire tead depth gauge

tire tread

A tool used for the singular purpose of measuring how much tire tread is left. An important length if there ever was one. Stay safe and keep the length of your tire treads as long as possible to keep your grip on the road.

Pi tape

Not that kind of pie. Pi tapes are similar to a fancy measuring tape. Perfect for measuring the length around an object (circumference).

Football chains

measuring football distance with chains

They are used for a measurement of a single length only, but they do it admirably. The first down distance of 10 yards is measured by a “chain gang” crew of officials who are tasked with keeping tabs on the location of the game ball.

 

Wow! Who knew there were so many length measuring tools out there in the world?

I tried to get all of the measuring instruments listed all in the same place but if I forget any, make sure to let me know by leaving a comment below. I’ll make sure to add it to the list.