[Envy Lawn Service]

I need some really high quality, really strong 5/16 bolts. What kind/grade do I need to buy? I snapped one from Lowes which was just a standard bolt (long story).

 

[specialtylc]

Caterpillar Tractors use a grade #9. or just go back to Lowes and get the grade #8.

 

[Envy Lawn Service]

OK, thanks.... looks like my thinking was backwards. I would have thought the cheaper bolts would be softer and just bend instead of snapping in half.

 

[relakst]

Try aircraft-grade bolts.

 

[grassredneck]

Grade 8 bolts should be plenty strong enough, if they aren't strong enough-I'd suggest going to a specialty supply store that specializes in fasteners

 

[Luscious Lawns]

Grade 8 bolts have 5 raised "stars" on the heads. They should be strong enough for most L/S engineering. Try checking if some other fastner has failed and is shifting the load to the bolt that is actually failing.

 

[DennisF]

If you need some really good bolts, look into a company called ARP. They make all sorts of different fasteners for high performance applications. But they are expensive.

 

[rookiemower]

different bolts work good in differernt applications, sometimes different grades are more brittle than others thats why some lower grades might be a little more flexible instead of just snapping which usually takes a whole sh*t load of pressure

 

[Shady Brook]

I am with Rookiemower, it depends on the application.

If you have something that takes alot of abuse and shock, you may want a grade 5, a grade 8 will be stronger, but will be more inclined to shear. Look at the bolts on plow rigs...grade 5. Look at the bolts used to mount big strong trailer hitches...grade 5. I don't think there will be much need for anything beside a 5 in a lawn type application.

Jay