Oil Canister Bolt Finish?

[Douglas C.]

Simple Question...

I disassrmbled the Oil canister on my '63 today and was getting ready to send the bolt to the platers. In looking at the bolt (with "M" headmark), it doesn't appear to have ever been plated. So my question is whether the bolt was originally plated (zinc or cadium) or just left as natural steel?

Thanks in advance for any responses.

--Doug

[Joe L.]

Simple Question...

I disassrmbled the Oil canister on my '63 today and was getting ready to send the bolt to the platers. In looking at the bolt (with "M" headmark), it doesn't appear to have ever been plated. So my question is whether the bolt was originally plated (zinc or cadium) or just left as natural steel?

Thanks in advance for any responses.

--Doug

Doug-----

The bolt was definitely not plated cadmium or zinc. It was either plain steel or black phosphate. I don't recall which but somebody else should know.

[Thomas N.]

The bolt should be natural or possibly black phosphate. Enclosed is a picture of a NOS cannister I have.
If you want any other pictures, let me know.

[Keith B.]

Here is anther NOS one
IMG_6491.jpg

[Gary B.]

Guys,

I have four comments and observations:

1) The bolt head in Keith’s photo looks cad or zinc to me.

2) I checked with Richard Fortier today for his input. Richard worked at AC from 1964 thru 1970 and he knows a lot about the oil canister. He said he believes most canister bolts were cad or zinc plated. At Paragon, and now on his own, Richard has overseen the restoration of hundreds of canisters and he said the original plating he typically sees on the protected shank of the bolt is cad or zinc. Note that Richard wasn’t there in 1963, so maybe ‘63 bolts were different.

3) Given that original bolts have been found with 4 or 5 different headmarks, there must have been 4 or 5 different suppliers to GM. Perhaps the original GM engineering drawing allowed for the bolt to be supplied with other than cad or zinc plating. Which would explain why some NOS examples can be found unplated. If anyone has access to the engineering drawing, that might be informative.

4) The ‘66 TIM&JG says “A single, 3/4” cadmium or zinc plated hex bolt secures the canister to the block.” Anyone is free to restore their canister bolt with whatever finish they choose. But at least for a ‘66 being judged, if the bolt head doesn’t look cad or zinc the owner can expect a deduction.

Gary