what grade should engine support bolts be ?
03-09-2007, 02:02 PM
#21
Geronimo36
Gold Member
In all my years doing this, 99% of all the motor mount bolts I've ever seen are steel. The zinc chromate plated helps with the corrosion. Also, most of the offshore mount thru bolts have always been fine thread steel, not coarse.
03-09-2007, 03:48 PM
#23
Emerald Coast of Florida
Gold Member
Join Date: May 2004
Location: Navarre FL
Posts: 623
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Interceptor
Another thing everyone should be very concerned about is there are a lot of fake hardware manufacturers out there.
I'm in the military equipment business and virtually every fastener we use is grade 8. A number of years ago a lot of fake grade 8 stuff was being made in Taiwan.
ed
I'm in the military equipment business and virtually every fastener we use is grade 8. A number of years ago a lot of fake grade 8 stuff was being made in Taiwan.
ed
03-09-2007, 04:03 PM
#24
Banned
Join Date: Sep 2001
Location: Deland, Florida
Posts: 25,191
Likes: 0
Received 0 Likes
on
0 Posts
I've heard that grade 8 shears more easily than grade 5, even though it has a higher tensile strength. I don't know for sure. I do know that grade 8 doesn't rust as quickly as lower grade bolts.
03-09-2007, 04:13 PM
#26
Registered
There should be businesses that specialize in fasteners in any decent size city. Here in the Detroit area I can think of about 6 right off the top of my head. They are much cheaper than ARP. Get the grade 8 and you'll be fine.
03-09-2007, 04:19 PM
#27
Geronimo36
Gold Member
Originally Posted by rdp145
Isn't tensile strength and shear different? I would think the highest shear strength is what your after for Motor mounts. And I don't think that SS?
Platinum Member
03-09-2007, 11:02 PM
#29
Registered
Originally Posted by THEJOKER
NO STAINLESS.....I learned the hard way. Sheered them right off and motor was lying in bildge! Grade 8.....
Something I have noticed on aftermarket truck suspensions they use Grade 5 bolts. But they are very large diameter, 7/8ths etc.
03-10-2007, 02:12 AM
#30
Registered
Join Date: Jun 2004
Location: Phoenix, Havasu, Newport
Posts: 3,062
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by RonS
My under standing has always been that you do not want to use stainless for motormounts because of the fact that stainless is more brittle and has a tendency to shear off.
