Sorry for this small anal question, but what is the orginal bolt for the battery hold down clamp? The size is 5/16NC but does it have a captured washer and no threads on the end just like a door hinge bolt?
Mine, which I believe to be original, is a 5/16"-18 recessed hex head with a captured conical washer and a reduced-diameter round flat point (we called them "dog-point" bolts in the plant).
Nice timing on this! :) John, what size is the captured washer? Thanks!
That souinds like what I bought, but the washer has teeth. It lokks exactly like a door hinge bolt.
I have an original bolt off a 68 full size car that I will look at when I get home. I think the head markings are RBW but I'll double check. I'll try to take an image of it tomorrow.
Washer is 7/8" in diameter, and it does have serrations ("teeth") on the bottom.
The one I have also has a 7/8" diameter washer but it doesn't have serrations on the bottom. The length is 1" including the washer.
RBW head marking, grade 5 (three lines). Remember, this is off a 68. Anyone else have an original bolt?
Quote from: JohnZ on November 08, 2007, 07:16:17 PM
Washer is 7/8" in diameter, and it does have serrations ("teeth") on the bottom.
That's what I thought. It is exactly a door hinge bolt, but the closest they could come. There is no AMK Products listing for the GM part number in the AIM.
Wow. I go out to my spare bolt bag and find 2 like you guys describe. If only I had known.
JohnZ,
What is the marking inside the head? Is it an "N" like the one shown?
This is AMK's individual bolt kit #G4352, $1.50. It is also avalible in a set of (6) for $5, item #B-11915.
Its a 5/16-18 x 7/8, 1/2 across the flats, 3/4 conical encapsulated washer, phosphate gray-black color. It has a "lead point" tread start nose tip w/o treads for about first 1/8".
<<JohnZ,
What is the marking inside the head? Is it an "N" like the one shown?>>
Here's a photo of the bolt on mine. Although the overall configuration of the bolt is similar to the door hinge bolt, I wouldn't expect them necessarily to have the same headmark - Fisher Body released and purchased the door hinge bolts under their own part number, and Chevrolet released and purchased the battery hold-down bolt under their own part number.
John,
See your clamp is painted, is that correct? I always thought those were phosphate like in Dave's photo.
Quote from: Pex68 on March 18, 2008, 07:47:29 PM
John,
See your clamp is painted, is that correct? I always thought those were phosphate like in Dave's photo.
I suppose they could have been either way, although I've only seen them painted; mine is original to the car.
I purchased mine hold down clamp from Paragon Corvette Reproductions, Kit Item #1515K, $5.00 which includes bolt Item #1498, "E" head mark. I must assume there could have been a couple of different bolt head markings uses.