63 Rocker Panel screws finish

[Edward J.]

I have some mixed results of what the finish on the screws that retain the lowers rocker panels. Maybe some of you 63 guys can tell me which finish belongs on them. or what you judges like to see.

[Harry S.]

Re: 63 Rocker Panel screws finish

Cad finish

[Edward J.]

Re: 63 Rocker Panel screws finish

Harry, did either of your 63's have a black finish, I have seen some 63' s with black -- original ???

[Michael H.]

Re: 63 Rocker Panel screws finish

Would these be the 5/16" hex head with integral washer?

[Edward J.]

Re: 63 Rocker Panel screws finish

Yes Mike that is the screws configuration.

[Michael H.]

Re: 63 Rocker Panel screws finish

Yes Mike that is the screws configuration.

Ed

I just looked at the original print. Harry is correct. The finish is supposed to be cadmium.

Poor memory but wasn't there two different design screws used for 63? One for early cars and the 3830604 for later cars?

[Edward J.]

Re: 63 Rocker Panel screws finish

Mike the only thing that I know that different was the earlier cars had 4 Philips head screws that retain the sides,2 front and 2 on the rear sides of the rockers. the later used just two screws, one at each end.

[John D.]

Re: 63 Rocker Panel screws finish

Edward, There are two variations of those Sems screws. Some with a circle around the logo and some plain. As I mentioned in an older post my 63 has had those screws replated several times. My 63 has had those screws replated several times. Black, cad and back and forth. John

[Alan D.]

Re: 63 Rocker Panel screws finish

Michael the 3830604 is the same used for 1964. In the past have had the same question on finish.
My original SEMS are black, Mar64. A number of people have reported that their originals were also black. A search in Noland's book shows a mix
At one time LIC said they had a print showing the finish to be black, however I've seen your print with the call for cad.
So - bottom line Who Knows, not me. (I just left mine as is)

[Michael H.]

Re: 63 Rocker Panel screws finish

Michael the 3830604 is the same used for 1964. In the past have had the same question on finish.
My original SEMS are black, Mar64. A number of people have reported that their originals were also black. A search in Noland's book shows a mix
At one time LIC said they had a print showing the finish to be black, however I've seen your print with the call for cad.
So - bottom line Who Knows, not me. (I just left mine as is)

Alan

I suppose it could be black cadmium but it doesn't specify. I don't have any info on the 4341-M spec.

I just looked at the original GM print for 3830604 again. It states;

Cadmium plate GM 4341-M

Finish to be as taken from plating bath.

[Joe R.]

Re: 63 Rocker Panel screws finish

Michael,

I've taken several 63's and 64's apart thru the years. (destroyed a couple) Have never seen any cad plated screws or even a trace of cad plating on any. All seem to be (rust) black phosphate. Does not the spec from GM specify the minimum spec for screws, bolts, nuts etc.? Could it be that GM or some nut case thought black phosphate to be a superior finish than the mil spec 4341-M??

JR

[Michael H.]

Re: 63 Rocker Panel screws finish

Michael,

All seem to be (rust) black phosphate. Does not the spec from GM specify the minimum spec for screws, bolts, nuts etc.? Could it be that GM or some nut case thought black phosphate to be a superior finish than the mil spec 4341-M??

JR

JR

It's possible that the screws are black cadmium. (yes, there is such a thing)

[John D.]

Re: 63 Rocker Panel screws finish

After a part is cadmium plated it's a simple process to have it chromated. Chromate comes in various colors. One of the colors is black.
Maybe they did that in the old days when cadmium was readily available and popular due to it's ability to withstand the elements better than zinc.
But today if you asked for black cad you would probably end up getting black zinc.
Black zinc is far superior to black phosphate you know. Trouble is at first the black zinc is a tad too shiny. But after a while it tones down.
I will ask my plater if he does black cadmium.

[Michael H.]

Re: 63 Rocker Panel screws finish

After a part is cadmium plated it's a simple process to have it chromated. Chromate comes in various colors. One of the colors is black. Maybe they did that in the old days when cadmium was readily available and popular due to it's ability to withstand the elements better than zinc.But today if you asked for black cad you would probably end up getting black zinc.Black zinc is far superior to black phosphate you know. Trouble is at first the black zinc is a tad too shiny. But after a while it tones down.I will ask my plater if he does black cadmium.

JD
You are correct. (first time) I just looked it up and the various colors come from a conversion coating over the cadmium. Here's a link.

http://www.chemprocessing.com/finishes/cadmium-plating.html