Where to find mounting bolts?

[caprirs302]

Okay, so i had replaced the factory studs with American bolts, but nonetheless the torque of the motor managed to shear off one of the mounting bolts.

Now I am in the midst of finding a stronger replacement bolts so that hopefully this doesn't happen again, but when I went to my local hardware store, they said that they didn't carry any "grade 8" metric bolts. Is there such a thing? If so, where can I track down some hardened metric bolts?

 

[Al.Fisherman]

Metric bolt grades and torque specs..

Bolt size....Low Grade....Grade 8.8....Grade 10.9....Grade 12.9
6mm............3-5................7..............10....................12
8mm...........8-12..............17..............24....................29
10mm........15-22..............33..............47....................57
12mm............39...............59..............83..................100
14mm............60..............101............131..................158

 

[GearNut]

Are those torque specs in inlb, ftlb, or nm?

 

[Al.Fisherman]

Sorry...that would help....Foot #'s

 

[mattysids]

Sick Bike Parts carries a kit based on replacing all of the old studs coming off the engine and all other screws/bolts for $10

 

[Porkchop]

Metric bolt grades and torque specs..

Bolt size....Low Grade....Grade 8.8....Grade 10.9....Grade 12.9
6mm............3-5................7..............10....................12
8mm...........8-12..............17..............24....................29
10mm........15-22..............33..............47....................57
12mm............39...............59..............83..................100
14mm............60..............101............131..................158

So what is this telling us ? Are these torque settings for the stated grade and size bolts for these engines only ? I'd be afraid to torque anything to 158 ft/lbs on these engines. The bolt it's self may take it, but I don't think the engine block would. I too need to know as I'm fixing to replace all factory nuts and bolts on a Grubee. Thanks !

 

[Al.Fisherman]

So what is this telling us ? Are these torque settings for the stated grade and size bolts for these engines only ? I'd be afraid to torque anything to 158 ft/lbs on these engines. The bolt it's self may take it, but I don't think the engine block would. I too need to know as I'm fixing to replace all factory nuts and bolts on a Grubee. Thanks !

I did a edit but it didn't post. This chart shows what he was asking about grades. I had posted that I, myself wouldn't go beyond the 8.8. The stud would take it but the case wouldn't. I delt with Volkswagen's back in the early 80's and had a problem with studs pulling out of the block. Had to either use over size studs or a heli coil.

 

[Porkchop]

Thanks for clarifying. I'm a firm believer in torque wrenches.