Blade Bolts

J

johnbell47

Member
my Diesel Z uses a 5/8 x 11 x 3 inch bolt for the blade bolts. They are a grade 5 bolt. Wondering if a grade 8 bolt would be ok in this application. I have the grade 8 bolts in the bin, no grade 5's.
 
Definitely use Grade 8. Matter of fact the high strength is all I stock in screws [bolts]. It actually reduces my inventory load. The only to use Grade 5 or less is shear bolts.
 
Just wait till you have to drill a grade 8 out. Will be passing up those in a hurry looking for grade 5.

Torque spec on grade 5 dry is 112 ft lbs. Pretty gundy for a blade bolt. If you are breaking those, something else is wrong.
 
slomo said:
Just wait till you have to drill a grade 8 out. Will be passing up those in a hurry looking for grade 5.

Torque spec on grade 5 dry is 112 ft lbs. Pretty gundy for a blade bolt. If you are breaking those, something else is wrong.
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You be pushing it at 110 ft lbs on a Bad Boy which why theirs is a grade 8.

And have you ever heard of carbide bits?
 
StarTech said:
You be pushing it at 110 ft lbs on a Bad Boy which why theirs is a grade 8.

And have you ever heard of carbide bits?
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5/8" grade 8 fine thread will take anywhere from 180 ft.lb. to 240 ft.lb. depending on whether it's lubricated, zinc plated or dry. They will take 110 ft.lb. easily. I certainly wouldn't use a grade 5 bolt for blades.
Gravely uses grade 8 bolts.
 
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And Gravely/Ariens are b?tch to get off as they want to use anti-seize on the threads so during mowing the bolts get even tighter. I am trying some Belleville washers to see if it can relive this slippage problem. I won't know until the mower comes back in for new blades.
 
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StarTech said:
And Gravely/Ariens are b?tch to get off as they want to use anti-seize on the threads so during mowing the bolts get even tighter. I am trying some Belleville washers to see if it can relive this slippage problem. I won't know until the mower comes back in for new blades.
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The blade bolts on my Pro Turn 260 come off fairly easy. It came with the concave (Belleville) type washers. My 1/2" Dewalt 20vMax impact rips them right off. I did apply a very small amount of anti-sieze after the initial blade change. I haven't put any more on them. There's really no need, I can still see some in the threads.
 
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