Shear Pin for brush hog

[Dirtball]

Is there a symbol ot letters on the head of a shear pin. Or do we just use grade 3 or lesser junk hardware.. It's a 60 in. HD rotary brush cutter. oh and anyone have a tip to re-assemble the collar over the grease fitting on the end of a pto shaft? it's a plastic inner ring that snaps? into the outer ring somehow and possibly turns to twist lock? Italian made generic brush cutter......thanks

 

[border collie]

Most 60" and 72" I've seen call for an 8mm grade 8.8 bolt (I think by 50mm length, but measure). The smaller hogs call for an SAE grade 2.

 

[Soundguy]

If in doubt about the proper shear pin to use, default to the lowest grade available and size the bolt to fit the bore perfectly.

My rotary cutter uses a grade 2 bolt..

Soundguy

 

[Typhoon]

Most likely a grade 2 bolt. You want the shear bolt to be the weakest link, so that it snaps before anything else does!
-Brad