Craftsman M110 Mower Blade (Size & Fitment Guide)
The Craftsman M110 uses a nominal 21-inch mower blade, and 942-0741A is a common OEM reference. That number and length are not enough to confirm fit. Check the mower’s full model number, parts list, blade-center profile, and adapter before buying. Match the original hardware, follow the correct manual’s torque value, and never run a blade that vibrates or feels loose.
A mower blade can look right on a parts shelf and still be wrong at the center hole. That small mismatch matters: the adapter and blade must seat together so the blade stays secure as it spins. I use the mower’s model information and the original blade as a pair of checks, rather than relying on “21-inch M110” alone.
Confirm M110 Model, Blade Size, and Mounting Profile
The M110 is a 21-inch walk-behind mower, but the correct replacement depends on the mower’s full model number and blade mounting details. A common OEM blade reference is 942-0741A; parts listings and revisions can vary. Confirm the number in the parts list for your exact mower before you buy.
Find the full model number
Look for the mower’s identification label and record the complete model number, including any suffixes or extra digits. Use that number to find the model-specific parts diagram or manual through Craftsman or the manufacturer’s parts support. Do not select a blade from the M110 name alone.
A model-specific diagram helps you check more than the blade number. It can show the blade adapter, bolt, washer, and their order. If a retailer’s listing gives only a broad fit claim, compare it with the parts diagram and ask the seller to confirm compatibility with your complete model number.
Check length and center fit
The nominal cutting width is 21 inches. For a replacement, compare the new blade’s listed length with the original and the model’s parts information. A tape measure can help identify a wrong-size blade, but it cannot confirm that the center profile or mounting arrangement is correct.
The center profile is the shape and configuration where the blade meets the adapter. Some blades use a shaped or star-like center rather than a plain round hole. Match the new blade to the original profile and adapter. A blade that slips over the bolt but does not seat correctly is not a safe fit.
| Check | What to confirm | Why it matters |
|---|---|---|
| Mower identity | Full model number, including suffixes | M110 versions may have different parts listings |
| Blade length | 21 inches nominal; compare with parts list and original | Prevents choosing a blade of the wrong size |
| OEM reference | 942-0741A is a common reference; verify by model | Parts listings or revisions may vary |
| Center profile | Shape matches the original blade and adapter | A mismatch can prevent secure seating |
| Hardware | Correct adapter, bolt, and washer arrangement | Incorrect or damaged hardware can compromise fit |
Do not assume a blade is compatible because the bolt passes through its center. If the blade rocks, shifts, or does not sit flat against the adapter, stop and confirm the part number and profile. Next step: verify the full model number before ordering, then compare the replacement with the original blade and diagram.
Prepare the Mower and Replace the Blade Safely
Blade replacement begins with making the mower unable to start. Disconnect the spark-plug wire and keep it away from the plug. Wear gloves and eye protection, follow the manual’s instructions for fuel and mower position, and use the correct hardware and torque for the exact model.
Make the mower safe to work on
Turn off the mower and let hot parts cool. Disconnect the spark-plug wire and secure it so it cannot touch the plug while you work. Follow the operator’s manual for fuel handling and tipping direction; tipping the mower the wrong way can let oil or fuel reach the air filter or muffler.
Wear sturdy gloves when handling the blade, even if it looks dull. The cutting edge can still cause a serious cut. Keep the mower stable on a level work surface, and do not rely on a jack or an unstable stack to hold it.
Remove and inspect the blade
Block the blade so it cannot turn while you loosen the bolt. Use a suitable tool for the fastener, and keep your hands clear of the cutting edge. Before removing the blade, note which side faces the deck and how the adapter and hardware are arranged. A photo can help you restore the original order.
Once removed, inspect the blade, bolt, adapter, and deck. Do not reuse a blade with a crack or bend, or an adapter that is damaged. Check for wear around the center mounting area. Replace damaged parts with components specified for the mower; do not try to make a mismatched center fit.
Install and test the replacement
Fit the replacement in the original orientation, seated fully against the correct adapter. Use the correct hardware and tighten the bolt to the value in the manual for your full model number. Some applicable MTD/Craftsman manuals specify 450–600 in-lb, or 37.5–50 ft-lb, but do not treat that range as universal. Check your manual before tightening.
After tightening, rotate the blade by hand to check that it clears the deck. Reconnect the spark-plug wire only after the blade is installed and tools are clear. Start the mower outdoors and listen and watch for abnormal vibration or contact. Stop at once if either occurs; disconnect the plug wire again and recheck the fit.
A mismatched center profile or poorly seated adapter can let the blade shift or loosen. A blade failure at operating speed can eject metal and cause severe injury. If you cannot confirm the fit or correct torque, do not run the mower until you have checked the manual or obtained help from a qualified service provider. Next step: verify the blade is seated, secure, and clear of the deck before starting.
Sharpen, Balance, and Inspect the Blade
Sharpening restores a dull cutting edge; balancing checks whether the blade has equal weight on both sides of its center. A straight, uncracked blade may be sharpened if the manual allows it. A bent or cracked blade should be replaced, not ground straight or sharpened.
Decide whether to sharpen or replace
A blade may need attention if it leaves ragged grass tips or cuts unevenly, but first rule out other causes such as an uneven mowing height or a problem with the mower deck. Remove the blade for inspection rather than reaching under the deck. Look for cracks, bends, deep nicks, and damage around the mounting center.
Replace a blade that is cracked or bent. Sharpening cannot restore its structural strength or correct a bend. A blade with severe damage or major material loss should also be replaced if it no longer matches the original shape or specified part.
Preserve the bevel and balance
The bevel is the angled surface that forms the cutting edge. When sharpening, preserve the original bevel instead of creating a new angle by eye. Remove equal material from both ends to keep the blade’s weight balanced. Uneven grinding can make one end heavier, causing vibration and extra stress on the mower.
Check balance with a suitable blade balancer after sharpening. If one end drops consistently, remove a small amount of material from the heavier end, then check again. Do not grind the center mounting area or alter the blade’s profile to force a fit. If the blade cannot be balanced without removing too much material, replace it.
| Blade condition | Recommended action | Avoid |
|---|---|---|
| Dull, straight, no cracks | Sharpen to the original bevel; balance afterward | Grinding more from one end |
| Bent blade | Replace with the model-correct blade | Trying to straighten or sharpen it |
| Cracked blade | Replace immediately | Reinstalling or welding it |
| Damaged center or adapter | Replace the affected specified part | Using a blade that rocks or shifts |
| Vibration after installation | Stop, disconnect plug wire, and inspect | Continuing to mow to “test it” |
Next step: after sharpening, confirm both the cutting edge and balance before reinstalling the blade.
Real-World Fitment Checks: Two Common Scenarios
These examples describe practical checks, not a claim about a particular owner or mower. They show why blade length alone does not prove compatibility. In both cases, comparing the full model number, original blade, adapter, and parts diagram helps prevent a guess from becoming a safety problem.
The blade is 21 inches, but the center is different
An owner finds a 21-inch blade listed for several walk-behind mowers. It measures the expected length, but its center opening does not match the original blade’s profile. The bolt fits through, yet the blade does not sit flat on the adapter. The correct action is to stop, verify the model-specific part listing, and obtain a blade with the matching center fit.
The correct part number is listed, but vibration starts
A replacement is listed against the mower’s model, but the mower vibrates after installation. The operator shuts it down, disconnects the spark-plug wire, and checks whether the blade is seated in the right orientation and whether the adapter and hardware are intact. If fit and torque are uncertain, the mower stays off until they are confirmed. Never assume vibration will settle down.
Takeaway: part listings are useful, but physical seating and safe operation still need to be checked.
Store the Blade and Mower for Seasonal Care
Seasonal storage is a good time to inspect the blade and record its part details. Remove grass buildup only with the mower disabled as the manual directs, and keep the blade protected from moisture. Before the next season, check for damage, secure mounting, and the correct blade fit rather than discovering a problem during the first mow.
Before storing or servicing the mower, follow its manual for fuel, cleaning, and storage. Do not handle the blade with the spark-plug wire connected. If you remove the blade for sharpening or replacement, keep its model information and part number with your maintenance notes.
A simple record can prevent a repeat search next spring:
- Full mower model number
- Blade part number shown in the parts list
- Blade length and center profile
- Date sharpened or replaced
- Any adapter or hardware replaced
Before mowing again, inspect the blade for cracks, bends, and loose or damaged hardware. Confirm the blade turns without touching the deck, and follow the manual’s tightening instruction. Next step: keep the model number and verified blade reference with your mower records.
Frequently Asked Questions
These answers focus on the fit and safety details most likely to affect an M110 blade purchase or replacement. Because the mower’s full model number controls parts compatibility, use it to check the manual and parts diagram whenever a listing, measurement, or installation detail is unclear.
What size blade does a Craftsman M110 use?
The M110 uses a nominal 21-inch blade. Confirm the size and part reference against the parts list for your mower’s full model number.
Is 942-0741A the correct M110 blade?
It is a common OEM reference, not a guaranteed match for every M110 version. Check the exact model’s parts diagram before purchasing.
Can I buy any 21-inch blade for the M110?
No. The center profile and mounting arrangement must match the original blade and adapter. Length by itself does not establish compatibility.
How do I find my M110’s full model number?
Check the mower’s identification label and record all digits and suffixes. Use the complete number when searching the manual or parts list.
Will a blade with a round center hole fit?
Only if that profile matches the original blade and adapter. Do not assume a round hole will seat securely; compare the parts and verify fit.
What torque should I use on the blade bolt?
Use the value in the manual for your exact model. Some applicable manuals specify 450–600 in-lb, or 37.5–50 ft-lb, but that range may not apply to every version.
Can I sharpen a bent M110 blade?
No. Replace a bent blade. Sharpening does not correct the bend, and a damaged blade should not be operated.
How can I tell if a sharpened blade is balanced?
Use a suitable blade balancer. If one end repeatedly drops, the blade is not balanced; remove small, equalizing amounts from the heavier end and check again.
What should I do if the mower vibrates after blade replacement?
Stop the mower, disconnect the spark-plug wire, and inspect blade seating, adapter, hardware, and blade condition. Do not mow again until the cause is found and corrected.
Can I reuse the original bolt and adapter?
Only if they are the specified parts and are in good condition. Replace damaged or worn components with parts listed for the mower; do not compensate for a poor fit with different hardware.
(This article was written by one of our staff writers, Harrison Croft. Visit our Meet the Team page.)
