Before you begin. This procedure is general reference information, not professional advice. Equipment varies by manufacturer, model, and year. Always follow the documentation supplied with your equipment — where it differs from this page, follow the manufacturer. Verify that you have the tools, the working conditions, and the ability to do this task safely. If anything is unclear, if the equipment is damaged, or if the task exceeds your experience, stop and use a qualified professional. You are responsible for your own safety and for the outcome. This site accepts no liability for any loss, damage, or injury arising from the use of this information.
Specifications marked unverified could not be traced to a manufacturer source. Do not rely on them — obtain the value from your equipment documentation.
Summary
Most people buy a circular saw blade on two numbers: the diameter and the size of the hole in the middle. Those two get the blade onto the saw. They do not tell you whether it is safe there. The number that does is printed on the blade in smaller type — the maximum safe operating speed — and it has to be compared against a number printed on the saw, which is the no-load RPM on the nameplate. Milwaukee's instruction is blunt about the direction of that comparison: only use blades with a maximum safe operating speed greater than the no load RPM marked on the tool's nameplate.
The reason this catches people out is that saws which take identical blades do not run at identical speeds. Two Milwaukee 7-1/4 inch saws in front of us take the same 7-1/4 inch blade on the same 5/8 inch arbor, and one turns at 5,000 RPM while the other turns at 6,300. A blade that is comfortably inside its rating on the first saw is over it on the second, and nothing about the fit tells you that. This page walks the four numbers in order, says what to do when any one of them does not agree, and stops at the point where the answer is to buy a different blade rather than to try it and see.
Necessary equipment
| Item | Note |
|---|---|
| Documentation for your saw | The manufacturer gives the blade size and the arbor size for your saw. |
| Blade wrench for your saw | Milwaukee supplies a wrench with the tool for the blade bolt. |
| Work gloves | The teeth of a blade are sharp. |
| Eye protection | Wear eye protection for the test after you install the blade. |
| Bright light or a flashlight optional | The marks on a blade are small and often dark. |
| New blade for your saw material | Keep the package until the four numbers agree. |
Remove the power from the saw
Estimated 2 min
REMOVE THE POWER FROM THE SAW BEFORE YOU TOUCH THE BLADE.
Milwaukee tells you to unplug the tool before you change an accessory. The teeth can cut your hand.
- Set the saw to OFF.<1mReport a problem with step 1, Remove the power from the saw
- If the saw has a cord, remove the plug from the outlet.<1mReport a problem with step 2, Remove the power from the saw
- Milwaukee tells you to unplug the tool before you change an accessory.
- If the saw has a battery, remove the battery from the saw.<1mReport a problem with step 3, Remove the power from the saw
- Milwaukee tells you to remove the battery pack before you install a blade.
- Put the battery in a different place while you do this work.
- Wait until the blade stops.<1mReport a problem with step 4, Remove the power from the saw
- Milwaukee warns that the blade continues to turn after you release the switch.
Read the numbers from the saw
Estimated 5 min to 9 min
Source: M18 Brushless 7-1/4 in. Circular Saw Operator's Manual (Cat. No. 2631-20) · tier 1 · accessed 2026-07-29
Source: Heavy-Duty Circular Saw with Tilt-Lok Adjustable Handle Operator's Manual (Cat. Nos. 6390-20 and 6394) · tier 1 · accessed 2026-07-29
Source: M18 Brushless 7-1/4 in. Circular Saw Operator's Manual (Cat. No. 2631-20) · tier 1 · accessed 2026-07-29
Source: M18 Brushless 7-1/4 in. Circular Saw Operator's Manual (Cat. No. 2631-20) · tier 1 · accessed 2026-07-29
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
- Find the nameplate of the saw.1mReport a problem with step 1, Read the numbers from the saw
- The nameplate is usually a label on the body of the saw.
- The documentation for the saw carries the same numbers.
- Read the no-load speed from the nameplate.1mReport a problem with step 2, Read the numbers from the saw
- Milwaukee gives 5000 RPM for one 7-1/4 inch cordless saw.
- Milwaukee gives 6300 RPM for one 7-1/4 inch corded saw.
- Two saws that take the same blade do not turn at the same speed.
- Read the blade size for the saw.1mReport a problem with step 3, Read the numbers from the saw
- Milwaukee gives a blade size of 7-1/4 inch for both of these saws.
- Read the arbor size for the saw.2mReport a problem with step 4, Read the numbers from the saw
- Milwaukee gives an arbor of 5/8 inch for both of these saws.
- Write the three numbers on a label inside the case.
Read the numbers from the blade
Estimated 4 min to 8 min
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
KEEP THE PACKAGE OF THE BLADE UNTIL THE NUMBERS AGREE.
A shop accepts a return of a blade in its package.
- Put the new blade on a bench with the printed face up.<1mReport a problem with step 1, Read the numbers from the blade
- Hold the blade at the flat part between the teeth.
- Wear gloves.
- Read the diameter from the face of the blade.1mReport a problem with step 2, Read the numbers from the blade
- The diameter is usually the largest number on the face.
- The package gives the same number.
- Read the maximum speed from the face of the blade.2mReport a problem with step 3, Read the numbers from the blade
- This number is often smaller than the diameter.
- This number is the maximum safe operating speed of the blade.
- Use a bright light if the print is dark.
- Look at the hole at the centre of the blade.1mReport a problem with step 4, Read the numbers from the blade
- Milwaukee names two shapes, a diamond shape and a round shape.
- Read the size of the hole from the blade or from the package.
Compare the blade with the saw
Estimated 5 min
Source: M18 Brushless 7-1/4 in. Circular Saw Operator's Manual (Cat. No. 2631-20) · tier 1 · accessed 2026-07-29
DO NOT INSTALL A BLADE WITH A MAXIMUM SPEED BELOW THE NO-LOAD SPEED OF THE SAW.
A blade above its speed rating can break into pieces. The pieces move at speed and can kill you.
- Compare the maximum speed of the blade with the no-load speed of the saw.2mReport a problem with step 1, Compare the blade with the saw
- Milwaukee gives a rule for the speed of a blade.
- The maximum safe operating speed of the blade must be more than the no-load RPM of the tool.
- The blade number must be the larger number.
- A blade at 5500 RPM is correct for a saw at 5000 RPM.
- The same blade is not correct for a saw at 6300 RPM.
- Do not use the blade if its number is the smaller number.1mReport a problem with step 2, Compare the blade with the saw
- Return the blade to the shop.
- Do not use the blade for a short cut only.
DO NOT INSTALL A BLADE THAT DOES NOT MATCH THE SPINDLE.
Milwaukee states that such a blade is not central and causes loss of control.
- Compare the diameter and the hole of the blade with the numbers from the saw.2mReport a problem with step 3, Compare the blade with the saw
- The diameter must be the blade size that the manufacturer gives.
- The hole must match the spindle in size and in shape.
- Milwaukee states that a blade with a wrong hole is not central.
Examine the condition of the blade
Estimated 5 min to 7 min
DO NOT USE A BLADE WITH A CRACK OR A BROKEN TOOTH.
Milwaukee refuses these blades. A piece of the blade can move at speed and injure you.
- Examine the blade for a crack and for a broken tooth.3mReport a problem with step 1, Examine the condition of the blade
- Look at the body of the blade around the centre hole.
- Look at each tooth and at each slot in the body.
- Milwaukee refuses a blade with a crack or with a broken tooth.
DO NOT PUT AN ABRASIVE WHEEL OR A DRY DIAMOND BLADE ON THIS SAW.
Milwaukee refuses both of them. The wheel can break into pieces and injure you.
- Make sure that the blade is not an abrasive wheel.1mReport a problem with step 2, Examine the condition of the blade
- Milwaukee refuses an abrasive wheel on this type of saw.
- Milwaukee also refuses a dry diamond blade on this type of saw.
- Read the instructions from the manufacturer of the blade.
- Make sure that the blade is sharp.1mReport a problem with step 3, Examine the condition of the blade
- Milwaukee states that a dull blade increases the chance of kickback.
- Milwaukee also states that a dull blade puts a load on the tool.
Install the blade
Estimated 10 min to 20 min
Source: M18 Brushless 7-1/4 in. Circular Saw Operator's Manual (Cat. No. 2631-20) · tier 1 · accessed 2026-07-29
Source: 29 CFR 1910.243 — Guarding of portable powered tools · tier 1 · accessed 2026-07-29
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
- Hold the spindle lock button while you remove the blade bolt.2mReport a problem with step 1, Install the blade
- Milwaukee turns the bolt counterclockwise for removal on these saws.
- Keep the bolt and the outer flange together in a container.
USE ONLY THE BLADE WASHERS AND THE BOLT OF YOUR OWN SAW.
Milwaukee designs these parts for your saw. A wrong part can release the blade.
- Clean the spindle and the two guards.2mReport a problem with step 2, Install the blade
- Milwaukee tells you to remove the dirt and the sawdust.
- Milwaukee tells you to leave the inner flange in position.
- Put the blade on the spindle with the teeth in the direction of the arrow.3mReport a problem with step 3, Install the blade
- Milwaukee gives the arrow on the lower guard as the direction.
- Install the outer flange and the bolt.
- Hold the spindle lock button while you tighten the bolt.
MAKE SURE THAT THE LOWER GUARD RETURNS BY ITSELF.
OSHA requires an automatic and instant return to the covering position. An open blade can cut you.
- Move the lower guard with your hand.1mReport a problem with step 4, Install the blade
- Then release the guard.
- The guard must return to the covering position by itself.
- Speak to a service centre if the guard does not return.
- Connect the power to the saw again.<1mReport a problem with step 5, Install the blade
- Install the battery again in a cordless saw.
- Start the saw with no material below it.2mReport a problem with step 6, Install the blade
- Wear eye protection.
- Listen for a noise from the blade or from the guards.
- Set the saw to OFF if you hear a new noise.
Terminology
This page uses one term for each item and holds it throughout, as ASD-STE100 requires. Equipment sellers and other guides use the names below for the same parts.
- arbor
- Also called: arbour, arbor hole, centre hole, center hole, bore, spindle hole, the hole in the middle
- no-load speed
- Also called: no load speed, RPM, rpm rating, saw speed, free speed, how fast the saw spins
- maximum safe operating speed
- Also called: max rpm, blade rpm, speed rating, rpm rating on the blade, max speed
- circular saw blade
- Also called: saw blade, skilsaw blade, skill saw blade, wood blade, carbide blade, 7 1/4 blade
- kerf
- Also called: blade thickness, cut width, thin kerf, how wide the cut is
- lower guard
- Also called: blade guard, guard, retracting guard, the spring cover
When to use a professional
Stop if the lower guard does not return to the covering position by itself. Speak to a service centre. OSHA requires an automatic and instant return, and a guard that sticks is a defect and not an adjustment.
Stop if the blade is not central after you install it. Do not use the saw. A blade that is not central shows a worn spindle, a bent flange or a wrong hole.
Do not make a hole in a blade larger to fit a spindle. Do not use a shim or a washer to fill a hole that is too large. Buy a blade with the correct hole.
Do not sharpen a carbide blade with a hand file. Speak to a service that sharpens blades. A tooth with damage from a file can become loose at speed.
Stop if you cannot find the no-load speed on the saw or the maximum speed on the blade. Speak to the manufacturer of each one. Do not estimate either number.
Common questions
Can I put a smaller blade on my circular saw?
Only if the manufacturer of the saw says so, and most do not. The manuals read for this page give a single blade size for each saw — 7-1/4 inch for both of the Milwaukee saws quoted here — rather than a maximum. A smaller blade sits deeper relative to the guard and the shoe, so the depth scale stops telling the truth and the lower guard may not cover the teeth the way it was designed to. It is also less cut depth for no gain. Check your own manual before you assume a smaller blade is a free option.
Does the RPM number on the blade really matter?
It is the one comparison on this page that is not negotiable. Milwaukee's own wording is to only use thin kerf blades with a maximum safe operating speed greater than the no load RPM marked on the tool's nameplate, and the same manual carries the general form of it as a warning: only use accessories with maximum speed rating at least as high as nameplate RPM of tool. A blade turned past its rating is being asked to hold itself together against forces it was not tested for. When one lets go it does so at full speed and in pieces.
How do I know what my saw's RPM is?
It is on the nameplate, which is usually a printed label on the body of the saw, and it is in the specifications table of the manual under 'No Load RPM'. Do not take it from a retailer listing or from the model name. Two Milwaukee saws that both take a 7-1/4 inch blade on a 5/8 inch arbor run at 5,000 and 6,300 RPM respectively, so 'it's a seven and a quarter' tells you nothing about speed. Write the number on a label inside the saw's case and you will never have to look it up again.
The hole in the blade is a diamond, not round. Is that a problem?
It is a genuine difference and Milwaukee names both shapes explicitly: always use blades with correct size and shape (diamond versus round) of arbor holes, because blades that do not match the mounting hardware of the saw will run off-centre, causing loss of control. Some blades ship with a knockout so the same blade can serve either fitting, and once you knock it out you cannot put it back. Match the shape to your saw's spindle before you buy, not after.
Can I use a washer or a shim to make a blade fit a smaller arbor?
No. Milwaukee's instruction is to never use damaged or incorrect blade washers or bolt, because the blade washers and bolt were specially designed for your saw, for optimum performance and safety of operation. A reducing bushing that is not part of the saw's own hardware is a part carrying the entire load of a blade at several thousand RPM, and it is not the part the saw's designers tested. Buy the right blade instead — it costs less than the alternative.
What is thin kerf and do I need it?
Kerf is the width of the slot the blade cuts, which is set by how far the teeth stick out sideways from the body. A thin kerf blade removes less material, so it needs less power, which is why cordless saws are usually specified with them — Milwaukee's own selection instruction for the cordless saw quoted here says to use thin kerf blades. Thin kerf blades are also more prone to deflect in a long rip. If the manual specifies thin kerf, that is a specification and not a preference.
How can I tell if a blade is finished?
Look for the two things Milwaukee refuses outright first: a crack in the body, and a broken or missing tooth. Either is a reason to stop, because the piece that leaves a spinning blade goes wherever it likes. After that, judge sharpness by behaviour rather than by looks — a dull blade tends to overload the tool and increases the chance of kickback, and you will feel yourself pushing harder before you see anything on the teeth. A blade that has been through a nail is worth a very careful look around the affected teeth.
What torque should the blade bolt be?
Neither of the manuals read for this page prints one, so this page will not either. What both give is a method: hold the spindle lock, hand-start the bolt, then tighten it with the wrench supplied with the tool. That wrench is a specified length for a reason. If you want a number, it has to come from your own saw's documentation or from the manufacturer — a torque figure guessed for somebody else's fastener is exactly the sort of number this site refuses to print.
Related procedures
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Sources
Every specification on this page is traced to one of these sources. Tier 1 is a manufacturer document, a published standard, or a government safety authority. See Standards for the full tiering rule.
- Tier 1M18 Brushless 7-1/4 in. Circular Saw Operator's Manual (Cat. No. 2631-20)
- Tier 1Heavy-Duty Circular Saw with Tilt-Lok Adjustable Handle Operator's Manual (Cat. Nos. 6390-20 and 6394)
- Tier 129 CFR 1910.243 — Guarding of portable powered tools
Revision history
Current version 1 · updated 2026-07-29 · next review due 2027-07-29
- v1 · 2026-07-29First draft. The speed rule is quoted from two Milwaukee circular saw operator's manuals read on 2026-07-29 — one cordless at 5,000 RPM no load and one corded at 6,300 RPM no load, both 7-1/4 inch blade on a 5/8 inch arbor — which is also the evidence for the page's central point that fit does not imply speed compatibility. Guarding rests on 29 CFR 1910.243(a)(1). The DANGER level on the overspeed hazard is the true consequence of the act and is not softened. Blade bolt torque publishes as consult-the-manufacturer: neither manual prints a figure and a guessed one would be a rule 1 breach. Makita and DeWalt circular saw manuals were attempted as a second independent maker and could not be retrieved (HTTP 503 and HTTP 404 respectively); they are recorded under rejected so the next session does not repeat the attempt blind.
Corrections to this page are listed in the public corrections log. Reports that are credible and not yet verified are listed in the public errata register, and an open one renders above the step it concerns.
Comments and corrections
Found an error? A correction with a manufacturer source is applied and logged publicly. You can also write to corrections@fixchecklist.com.
Every step above carries its own report control, which tags the report with that step so a correction reaches the right place. For anything about the procedure as a whole — the order of the sections, a step that is missing, something that did not match your equipment — use this: report something about this whole procedure.