On 12/21/2010 9:34 PM, Steve Shipley wrote:
>
> I've been under the impression that Grade 5 bolts are rated for
> tension, not for shear. And certainly not intended to be bent.
Umm, just for drill, all grades have shear ratings. Shear strength is
derived mathematically from tensile strength tests (nominally, for
engineering purposes, I think it's something around 65% of tensile).
So, if tensile yield is XXXX, shear yield is 65% of that, and that's the
figure used to determine if the bolt meets proof loads in shear.
No bolt is intended to be bent, but, many are subject to shear loads,
too, so they have to be calculated for a given application. I've seen
3/4" GR8 bolts with u-sections bent into them from shear loads between
two plates that someone didn't calculate properly and didn't anticipate
the shear loads exceeding the ability of the clamping force to keep the
plates in position (too much slop in the through holes combined with
high shear forces causing the plates to slide back and forth and bang
against the bolt shank).
Cheers.
--
Michael Porter
Roswell, NM
Never let anyone drive you crazy when you know it's within walking distance....
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