Bolt Strength?

[xpinoyxmk]

I have brackets that i got to put evo 8 brembos up front and i need bolts. I went to an auto parts store to get some and they said that 8.8 grade bolts are not that strong and that i should try and find some 10.9 grade bolts.

So my question is, are 8.8 grade bolts stong enough and wont break?

[tunersedge]

Im unsure what the oem bolts are rated at, but an SAE Grade 8 is equivalent to Metric Class ~10.9 Bolt. One way to determine standard from metric is a standard grade 8 Bolt will have 6 evenly spaced radial lines, where as a metric will just have a number.

grade 8 bolt strength - Google Search (http://www.google.com/search?hl=en&q=grade+8+bolt+strength&revid=1118538369&ei=TOfISo_JC9WelAfe5tmSAw&sa=X&oi=revisions_inline&resnum=0&ct=broad-revision&cd=6)

the internet is your friend.

to directly answer your question, a SAE bolt grade 8 will suffice.

[Def]

No, you want class 10.9 bolts. You have class 8.8 bolts, which is like an SAE grade 5, and about 20% weaker than a grade 8/class 10.9 bolt.

[xpinoyxmk]

Anyone know where i could get 10.9 metric bolts?

Sizes i need are (4)M12-1.25 25-30mm and (4)M12-1.75 25-30mm

[tunersedge]

Ace Hardware, im not familiar with what hardware chains are in florida, but any hardware store would be a good start.

[GSXRJJordan]

Ace Hardware, im not familiar with what hardware chains are in florida, but any hardware store would be a good start.

Yeah, most hardware stores will have some high-quality bolts. Just make sure you're comparing Metric grade to Metric grade, and not SAE to Metric, or you'll get all messed up.

If you really can't find anything, McMaster Carr has everything in the world, for pretty cheap, and they ship same day. McMaster-Carr (http://www.mcmaster.com).

[duffman1278]

A grade 8.8 bolt would do you enough. You're not going to even reach that much of a force to even reach the point at which it elongates or to even shear it.

[ixfxi]

its a fucking caliper bolt


i too, agree with the above poster. to reach that level of stress, you'll need to do a lot more than extreme braking. i mean people are making caliper adapter brackets, which in my opinion can be questionable. the z32 calipers were made in alum, which again is questionable.

i think grade 8 bolts are pretty acceptable for a caliper bolt.

[xpinoyxmk]

Looking for stores that have a 10.9 grade metric bolts. Ace hardware and advance auto parts dont have them. McMaster doesnt have one of the sizes i posted above. Its the fine thread that no one has

I would rather be safe and sure than run the risk of the bolt snapping and me losing all me brake force and crashing. If i cant find a place that has them, then i might just get the 8.8 bolts

[JRas]

Mitsubishi dealership, parts department.. perhaps?

[ixfxi]

then do what normal humans do, buy them from the dealer


but the chances of 4 bolts just shearing off like that, is pretty fucking incredible. youve got a better chance of being eaten by a walking shark than breaking those caliper bolts.

[duffman1278]

youve got a better chance of being eaten by a walking shark than breaking those caliper bolts.

Exactly.

OP don't even over stress yourself about it, that 8.8 bolt can already handle alot more stress than you'll put those bolts through ever.

[jspaeth]

then do what normal humans do, buy them from the dealer


but the chances of 4 bolts just shearing off like that, is pretty fucking incredible. youve got a better chance of being eaten by a walking shark than breaking those caliper bolts.


hahah i literally just busted out laughing at work when I read this