John Deere Mower Blade Bolt Torque Specs
John Deere lawn tractors (D, E, S, X series) use a 5/8" blade bolt with the famous M115495 torque-to-yield bolt; ZTrak commercial Z-turns use a 15/16" stepped bolt with mandatory threadlocker.
What torque should I use on a John Deere blade bolt?
John Deere blade bolt torque is typically 40–55 ft-lb on a 15/16" socket with 5/8"-18 UNF thread. Threadlocker: Blue Loctite required on ZTrak and X300/X500 series. 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.
John Deere D130 (22HP, 42" Deck) blade bolt torque
40–45 ft-lb on a 15/16" socket with 5/8"-18 UNF thread. Twin-blade deck. Bolt M115495 is torque-to-yield — replace it, do not reuse.
John Deere Z355E (ZTrak, 48" Deck) blade bolt torque
50–55 ft-lb on a 15/16" socket with 5/8"-18 UNF thread. Apply Loctite 242. Replace bolt every cut season.
John Deere X300 Select Series (38"/42" Edge Xtra Deck) blade bolt torque
65 lb-ft (88 N·m) on a 15/16" socket with 5/8" nut thread. Blade NUT + washer on 38"/42" decks. The 48"/54" decks on the same X300 family use a BOLT at 50 lb-ft (68 N·m) instead — do not cross-apply. The 15/16" socket and UNF thread pitch aren't explicit in this manual; confirmed by the same 5/8" JD blade nut used in the S/E-series manuals below.
John Deere X350 Select Series (42A Deck) blade bolt torque
50 lb-ft (68 N·m). Blade CAP SCREW on 42A/48A/54A decks. The 42M mulching deck variant uses a NUT at 65 lb-ft instead. Screw size is not stated in this manual.
John Deere S100 (100 Series Lawn Tractor) blade bolt torque
65 lb-ft (88 N·m) on a 15/16" socket with 5/8" nut thread. Manual explicitly: "Using 15/16 in socket, tighten 5/8 in blade nut to specifications." Same spec across 42"/48"/54" decks.
John Deere S120 (100 Series Lawn Tractor) blade bolt torque
65 lb-ft (88 N·m) on a 15/16" socket with 5/8" nut thread. Shares OM (OMUC34183) with S100/S110/S130/S140/S160/S170/S180 — identical blade-nut spec across the whole 100 Series.
John Deere E120 (E100 Series Lawn Tractor) blade bolt torque
65 lb-ft (88 N·m) on a 15/16" socket with 5/8" nut thread. Manual explicitly: "Using 15/16 in. socket, tighten 5/8 in. blade nut to specifications."
John Deere Z335E (ZTrak, 42A Deck) blade bolt torque
50 lb-ft (68 N·m). 42A deck uses a BOLT at 50 lb-ft. The 48A/54A decks on the same Z335E/Z355E platform use a NUT instead — check deck code before applying. Bolt size is not stated in this manual.
Pro tip for John Deere blade service
The John Deere blade bolt (M115495 / M83472) is officially single-use on the X500/X700 series — the manual says replace it every blade change, $4 each, never reuse.
Step-by-step John Deere 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. Apply Blue Loctite required on ZTrak and X300/X500 series. Torque in one smooth pull with a calibrated torque wrench. Re-check after first hour of cutting.
Related lookups
- All Mower Blade Bolt Torque Specs
- Briggs & Stratton Blade Bolt Torque
- Walk-Behind Mower Blade Bolt Torque
- John Deere D130 (22HP, 42" Deck) (40–45 ft-lb)
- John Deere Z355E (ZTrak, 48" Deck) (50–55 ft-lb)
- John Deere X300 Select Series (38"/42" Edge Xtra Deck) (65 lb-ft (88 N·m))
- John Deere X350 Select Series (42A Deck) (50 lb-ft (68 N·m))
- John Deere S100 (100 Series Lawn Tractor) (65 lb-ft (88 N·m))
- John Deere S120 (100 Series Lawn Tractor) (65 lb-ft (88 N·m))
- John Deere E120 (E100 Series Lawn Tractor) (65 lb-ft (88 N·m))
- John Deere Z335E (ZTrak, 42A Deck) (50 lb-ft (68 N·m))
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