What grade shear pin in woods bush hog

[cspot]

My FIL has an old 6' Woods Bush Hog. Model 70 I think. Anyway it has a 7/16" shear bolt in it. I broke the shear bolt the other day when using it. I bought some grade 2 bolts to put in there. Now they break when you hit almost anything. What grade bolt should it be?

 

[travis potter]

If you have the old bolt check the head it will be marked as to the grade.

 

[RoyJackson]

If you have the original bolt, look at the head markings then google for "Bolt Head Markings" or "Bolt Grades". You probably won't see a grade number, but you will see a symbol or symbols.
I'd guess it's a Grade 5, but make sure you know which grade it must be. If necessary, call Bush Hog and ask them (but you'll probably need the model number).

 

[Willl]

Maybe you can find the manual for it here ?

Woods Equipment Company - Manuals

 

[cspot]

If you have the original bolt, look at the head markings then google for "Bolt Head Markings" or "Bolt Grades". You probably won't see a grade number, but you will see a symbol or symbols.
I'd guess it's a Grade 5, but make sure you know which grade it must be. If necessary, call Bush Hog and ask them (but you'll probably need the model number).

Unfortunately the bolt head was gone when it broke. The bushhog is at least 30 years old, but is still in good shape. Most bushhogs I have seen use a grade 2 bolt 1/2" in diameter. This is 7/16" so I wonder if it is a grade 5 bolt.

 

[cspot]

Maybe you can find the manual for it here ?

Woods Equipment Company - Manuals

I will have to get the exact model number, but the bushhog is at least 30 years old so I don't know if it will be online or not.

 

[RickB]

I will have to get the exact model number, but the bushhog is at least 30 years old so I don't know if it will be online or not.

Without the model number, you won't get reliable help here, either.

 

[kebo]

This is not rocket science here fellas. Most likely it was designed for grade 2 or grade 5 bolts. Suggest you start out with a grade 2 bolt and run it for awhile. If it doesn't shear right off (or start showings signs of being cut into) with normal use, then run it like that. If it seems to shear excessively (without hitting immovable objects) and/or does show signs of the shafts cutting into it, then you might want to consider replacing it with a grade 5 bolt.

 

[IslandTractor]

This is not rocket science here fellas. Most likely it was designed for grade 2 or grade 5 bolts. Suggest you start out with a grade 2 bolt and run it for awhile. If it doesn't shear right off (or start showings signs of being cut into) with normal use, then run it like that. If it seems to shear excessively (without hitting immovable objects) and/or does show signs of the shafts cutting into it, then you might want to consider replacing it with a grade 5 bolt.

Ditto. I wouldn't waste any time chasing down a thirty year old manual.

 

[keyser soze]

Grade 2 bolt is the industry standard.