David,
According to the late Carroll Smith, SAE Grade 8 bolts should never be used
in a shear application due to the following reasons:
1. SAE Grading is somewhat variable - "hardware store" bolts may be of
suspect origin and strength.
2. SAE bolts have loose tolerances as to diameter - leading to a sloppy fit
3. SAE bolts are more brittle than an AN bolt.
4. SAE bolt have too much threaded length - you either have to cut off the
excess or have threads under shear loads (not good)
You can get AN bolts at not to bad prices from places like Aircraft Spruce
for critical shear applications (lower A-arms, rear trailing arms, etc)
along with the appropriate AN locknuts.
McMaster Carr has a good selection of grade 8 bolts, washers, and nuts.
Hope this helps,
Hugh Barber
Hollister, CA
'73 TR6
-----Original Message-----
From: owner-triumphs@autox.team.net
[mailto:owner-triumphs@autox.team.net]On Behalf Of Davgil@aol.com
Sent: Tuesday, June 10, 2003 5:51 AM
To: triumphs@autox.team.net
Subject: Question about grade 8 bolts (no LBC)
To the list,
I have a question that may be overly simple for many of you, but I do not
know the answer and I am curious. I am working on a project that involves a
place that I will keep my TR6 eventually (the LBC content) and I have a
question
about bolt grades. The question very simply is this, if grade 8 bolts are
used with a lower grade nut does the whole assembly become a grade 2 or 5 or
whatever application based on the strength of the nut. In my particular
case, I
am more concerned about shearing force that I am stretching force if that
makes
sense and I was just curious about how these ratings work. I am on the
digest mode and if anyone can give me a simple answer, just reply off list.
Thanks in advance.
David Gill
1976 TR6
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