Weird: Corvette Bolt Missing
Race Director
Joined: Oct 2004
Posts: 10,089
Likes: 14
You won't be able to find Grade 5 or Grade 8 in metric.
Metric are 8.8 and 10.9 respectively, and will be stamped on the head of the bolt.
For an SAE bolt, three hash marks on the bolt head indicate Grade 5, and six indicate Grade 8.
As for plating, shiny silver bolts are generally Zinc coated, with a clear chromate finish.
Yellow bolts are Yellow Chromate, which offer a slightly higher resistance to "white rust" (or chalky corrosion), in areas of high moisutre.
Grade 8/10.9 bolts will be rated to 150,000 psi tensile strength, and Grade 5/8.8 bolts will have a 120,000 psi tensile strength rating.
While some suspension parts require Grade 8, or 10.9 metric, unless specified, or unless you need the additional resistance to corrosion, Grade 5/8.8 will be adequate.
Having all Grade 8 is fine, but weigh the benefit vs. costs.
Note- 68/70 Vette is correct- at Home Depot, your bolts may not even meet Grade 5 standards, and may not offer any corrosion protection, so get your bolts for your car somewhere reputable, like a good parts store, and check the bolt markings to ensure that they meet the strength and corrosion standards you require.
scotty,
former nut and bolt salesman
Metric are 8.8 and 10.9 respectively, and will be stamped on the head of the bolt.
For an SAE bolt, three hash marks on the bolt head indicate Grade 5, and six indicate Grade 8.
As for plating, shiny silver bolts are generally Zinc coated, with a clear chromate finish.
Yellow bolts are Yellow Chromate, which offer a slightly higher resistance to "white rust" (or chalky corrosion), in areas of high moisutre.
Grade 8/10.9 bolts will be rated to 150,000 psi tensile strength, and Grade 5/8.8 bolts will have a 120,000 psi tensile strength rating.
While some suspension parts require Grade 8, or 10.9 metric, unless specified, or unless you need the additional resistance to corrosion, Grade 5/8.8 will be adequate.
Having all Grade 8 is fine, but weigh the benefit vs. costs.
Note- 68/70 Vette is correct- at Home Depot, your bolts may not even meet Grade 5 standards, and may not offer any corrosion protection, so get your bolts for your car somewhere reputable, like a good parts store, and check the bolt markings to ensure that they meet the strength and corrosion standards you require.
scotty,
former nut and bolt salesman
Man knows his nuts and bolts. Almost any reasonably large town will have an industrial fastener dealer. Go there instead of to a big box store if you want good quality bolts at good prices. If you don't live near a large town, just go online to Maryland Metrics and buy your bolts from them. Good quality, good prices, good service.
Melting Slicks
Joined: Nov 2004
Posts: 3,064
Likes: 6
From: Pinellas Park Florida
I went to chevy to ask for a replacement bolt as the hole was clean (no broken bolt). They tol dme to go to a regulr hardware store as the bolt was M 12 X 1.75 X 30. Lo and behold 10 min. and $1.47 later, I'm back at my house attempting to bend the clamp back.
Finally got it on. had to rig upa set up including a socket wrench handle which I "threaded" through the clamp hole and "jacked" the clamp back up. Then used a LARGE 20 in. breaker bar to screw the bolt back on.
Finally got it on. had to rig upa set up including a socket wrench handle which I "threaded" through the clamp hole and "jacked" the clamp back up. Then used a LARGE 20 in. breaker bar to screw the bolt back on.
