Grade 5 Shear Bolts for Rotary Cutters 1/2" x 3-1/2" with Nylock Nuts - 5 Pack

What It Is

Grade 5 shear bolts (1/2" x 3-1/2") with Nylock nuts, sold in a 5-pack, designed for rotary cutters and brush hogs. These bolts are a sacrificial component that breaks under extreme load to protect your gearbox and driveline from shock damage.

Fitment & Compatibility

Before buying, check three things:

1. Bolt diameter and length – This is 1/2" diameter, 3-1/2" long. Measure your existing bolt; if it’s shorter or longer, this won’t fit securely.
2. Grade requirement – Grade 5 is standard for most rotary cutters (e.g., Bush Hog, Land Pride, Woods, John Deere). Do not use Grade 8 bolts here—they’re too strong and won’t shear, risking gearbox damage.
3. OEM vs. aftermarket – These are aftermarket but meet SAE J429 Grade 5 specs. They work as a direct replacement for OEM part numbers like Bush Hog 001090, Land Pride 315-310, or Woods 100-147. No brand-specific modifications needed.

Pro tip: If your cutter manual specifies a different length or grade, follow that spec. Using the wrong length can cause the blade to bind or the nut to loosen.

Key Things to Know

• Grade 5 is correct – These are medium-strength (120,000 psi tensile). They’re designed to snap before your gearbox or PTO shaft bends. Never substitute with Grade 8 or ungraded bolts.
• Nylock nuts are included – The nylon insert locks the nut without needing thread locker. Replace the nut each time you install a new bolt—old Nylocks lose grip.
• Installation is easy – Slide the bolt through the blade and spindle, hand-tighten the nut, then torque to 30-40 ft-lbs. Do not overtighten; you want the bolt to shear cleanly when hitting a rock or stump.
• Common gotcha – If your cutter uses a 5/8" or 3/4" bolt, this 1/2" won’t fit. Measure the hole diameter in your blade and spindle before ordering.

Should You Buy It

Buy this 5-pack if you own a standard-duty rotary cutter (5-7 ft deck) and want a reliable, cost-effective replacement for worn or snapped shear bolts. It’s ideal for routine maintenance or keeping spares on hand. Skip it if your cutter requires Grade 2, Grade 8, or metric bolts—check your manual first.