Craftsman Mower Blade Bolt Torque Specs

Craftsman T-series lawn tractors are MTD-built and retain the blade with a hex flange nut torqued to 70–90 ft-lb; the M105 walk-behind uses a single centre bolt at 450–600 in-lb. Both figures are quoted from the Craftsman instruction manuals. No socket or thread size is stated.

What torque should I use on a Craftsman blade bolt?

Craftsman blade bolt torque is typically 70–90 ft-lb (tractor) / 450–600 in-lb (walk-behind). Threadlocker: Not called for in the Craftsman manuals cited below. Always confirm the exact figure for your specific model — deck design, blade thickness, and spindle stack-up move the spec by 10–20 ft-lb between models in the same brand line.

Craftsman T110 (Lawn Tractor, 42" Deck) blade bolt torque

70–90 ft-lb with a hex flange nut. Blade spindle HEX FLANGE NUT, not a bolt. Craftsman T100 Series instruction manual 769-16711A (model CMXGRAM1130036 = T110 42"), p.29: "Use a torque wrench to tighten the blade spindle hex flange nut to between 70 ft-lbs and 90 ft-lbs." Nut size and socket are not stated.

Craftsman M105 21" Push Mower blade bolt torque

450–600 in-lb (37.5–50 ft-lb) with a hex bolt. Craftsman mower instruction manual 769-19750 (model CMXGMAM2703840 = M105), p.14, Blade Care step 8: "Replace hex bolt and tighten hex bolt to torque: 450 in-lb (min.), 600 in-lb (max.). To ensure safe operation of your mower, periodically check the blade bolt for correct torque." The manual prints inch-pounds only; the ft-lb figure is our conversion. Single centre bolt through the blade bell support into the blade adapter. Bolt size and socket are not stated.

Pro tip for Craftsman blade service

The Craftsman walk-behind manual prints its spec in inch-pounds (450–600 in-lb). Many torque wrenches read ft-lb only — that is 37.5–50 ft-lb; do not set 450 on a ft-lb wrench.

Step-by-step Craftsman blade-bolt reinstall

Disconnect the spark plug, engage parking brake, tip the mower (carb-side up). Block the blade with a 2×4 — never your hand. Use a 1/2" drive breaker bar with a 6-point socket. Clean threads with brake cleaner. No threadlocker needed unless your model manual specifies it. Torque in one smooth pull with a calibrated torque wrench. Re-check after first hour of cutting.

Related lookups

Loading interactive lookup…