MHarryE
Elite Member
- Joined
- Feb 15, 2009
- Messages
- 2,949
- Location
- Northeastern Minnesota
- Tractor
- Kubota M7-171, M5-111, SVL75-2, RTV900XT & GR2120; CaseIH 1680 combine
Are you sure grade 2 are recommended? None of my machines with shear bolts use grade 2. Two explain further. Grade 2 are a more ductile material that often deforms when it shears making the broken stubs more difficult to get out. Also, they are not made to the same quality standard as a grade 5 so shear torque is less predictable. Grade 5 is harder, more brittle, and is less likely to smear while shearing, and torque is more predictable. Depending on the design, tight shear bolts are less likely to shear so double nutting is good practice. The forage chopper I use for my nephew always gets double nutted or i get early unplugged failures. My New Holland baler has its own special shear bolt for main drive and knotter. They come with lock nuts.