9ft Topper shear bolt

No revs and engage pto very very slowly here

12.9 is too strong. 10.8 is normal shear bolt strength.

A few of the co-op for some stupid reason started packaging 8.8 bolts 10-15 years ago as shear bolts. 8.8 have have very low tensile strength. They are basically used to bolt something together that will come under very little pressure.

Bolts are graded to three characteristics, Proof load, yield and tensile strength. The PL is the load at which a bolt should not deform, it's about 60% of its TS. YS is the strength at which if a bolt comes under it will not return to its original characteristics. The TS is the strength a bolt will shear at.

However if a bolt is constantly put above its PL it's TS will decrease ( basically it's diameter gets narrower or it gets damaged) .

You might use an 8.8 rated bolt as a shear bolt on something like a fertlizer spreader. However in mower, toppers you always use 10.9 bolts. There YS is about the same as the TS of a 8.8 bolt and there PL would be 20% below that.

May as well use a haybob tine instead or weld the shaft soild

If your using 10.9s you won't break many 😅