19M7775 14M7303 Replace Hex Flanged Bolt & Nut for John Deere Mower Tractor （2pcs）

What It Is

This is a set of two replacement hex flange bolts and nuts (OEM cross-reference: 19M7775 and 14M7303) designed to secure mower blades to the spindle on John Deere lawn tractors and zero-turn mowers. The flange head distributes clamping force evenly, and the hardened steel construction resists stripping under high torque.

Fitment & Compatibility

Before buying, confirm the following:

• Blade bolt size: 5/16″-24 thread (fine thread) – measure your original bolt if unsure. This is not a standard 5/16″-18 coarse thread.
• OEM numbers: Fits John Deere part numbers 19M7775 (bolt) and 14M7303 (nut). Common on 42″ and 48″ Accel Deep decks, as well as many 100, 200, 300, X300, X500, and Z-series mowers.
• Deck types: Designed for stamped steel decks that use a single bolt and lock nut per blade. Not for fabricated decks or older models that use a bolt with a separate washer.
• Quantity: Two sets (bolt + nut per set). If your deck has three blades, you need two packs.

Key Things to Know

• Torque is critical: Tighten to 35–50 ft-lbs (check your manual). Over-torquing can strip the spindle threads; under-torquing can loosen the blade in use.
• Use threadlocker: Apply medium-strength threadlocker (blue Loctite) to prevent vibration loosening. The OEM design relies on the flange and nut, but threadlocker adds safety.
• Check spindle condition: Inspect the spindle’s internal threads for damage before installation. A damaged spindle will ruin a new bolt quickly.
• Grade difference: These are Grade 5 (or equivalent) hardened steel – fine for residential use. If you mow commercially or hit heavy debris, consider Grade 8 bolts.

Should You Buy It

If you need a quick, affordable replacement for a stripped or lost John Deere blade bolt and nut on a standard residential deck, this set is a solid choice. The high rating and low price make it a no-brainer for routine blade changes. Skip it if you need a bolt with an integral washer or have a commercial-duty fabricated deck.