bolt grades?
Thread Starter
Le Mans Master
Joined: Apr 2001
Posts: 5,305
Likes: 9
From: Weston FL
bolt grades?
I am sure, most are like me, when I have to replace a bolt / nut, if it is a crucial piece I got for the grade 8 (or largest grade available just to be safe). But, what "are the measurements or thresheholds on these grades? :confused:
I mean, how strong in one grade vs the other? Are there numbers anywhere to compare? :confused:
thanks
I mean, how strong in one grade vs the other? Are there numbers anywhere to compare? :confused:
thanks
Platinum Supporting Dealership
Joined: Dec 1999
Posts: 6,425
Likes: 1
From: Traveling the US
Race Director
Joined: Aug 1999
Posts: 18,126
Likes: 174
From: WI
Re: bolt grades? (yosshimura)
yosshimura,
I use grade 8 basically for suspension,steering and brakes only, Everything else gets a grade 5. By the way you have mail that you may like to post. ...redvetracr
I use grade 8 basically for suspension,steering and brakes only, Everything else gets a grade 5. By the way you have mail that you may like to post. ...redvetracr
Advanced
Joined: Jun 2001
Posts: 61
Likes: 0
Re: bolt grades? (yosshimura)
I'm no metallugist but my mechanically minded coworkers who know of such things warned me about this very subject. Since then, I have read some technical articles that corroborate what they said.
In short, harder is not always better.
The type of metal and hardness were originally chosen to perform a function. Altering them without knowing why they were chosen in the first place could put you, and others on the road, in jeopardy if that "crucial" fastener fails.
For example, a fastener that normally provides good shear strength may fail if a more brittle, hardened fastener is substituted. Some materials are more prone to hydrogen embrittlement than others. etc
Unless you understand the function, the materials and the process, I'd stick to OEM or equivalent fasteners.
I only offer this advice to avoid :nopity in the future
In short, harder is not always better.
The type of metal and hardness were originally chosen to perform a function. Altering them without knowing why they were chosen in the first place could put you, and others on the road, in jeopardy if that "crucial" fastener fails.
For example, a fastener that normally provides good shear strength may fail if a more brittle, hardened fastener is substituted. Some materials are more prone to hydrogen embrittlement than others. etc
Unless you understand the function, the materials and the process, I'd stick to OEM or equivalent fasteners.
I only offer this advice to avoid :nopity in the future
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
Re: bolt grades? (yosshimura)
I use grade 8 on alot of things but grade 10 on brake calipers and steering parts. I used some grade 12 and had them fail because they are too hard. I only use plated grade 5 on none escential parts like exhaust and fuel pumps, then again I use ss on exhuast. I also believe in studding anything that I can, valve covers, oil pans, the entire motor and especially the transmission mounts. Help align gaskets and prevents cross threading or stripped threads.
