69-72 PO3 Hub Caps - were these ever really chrome?

[DeadheadNM]

I sent five of what I believed were chrome 3/4t PO3 hubcaps for re-plating. The shop called to tell me the caps were in fact stainless so these were polished instead.

Three of these caps came from a low mileage k20 suburban survivor (see here http://67-72chevytrucks.com/vboard/s...d.php?t=467636 ) and I believe these are original to the truck. Another cap is an original blue bowtie convex example. A thin fridge magnet didn’t stick to any of these including the yellow bowtie example. I have a blue bowtie convex NOS cap and when I look closely it appears to have some “grain” to it so I suspect it’s also stainless not chrome.

Can anyone 1) show me how to confirm a chrome cap apart from a stainless cap and 2) prove there are chrome examples for 69-72 apart from highly polished stainless steel? Anyone have an example of chrome plate peeling from a cap?

Pics attached of before and after polishing.

[Ol Blue K20]

I don't know about chrome caps but the caps above sure are pretty.

[factorystock]

This topic has been discussed a while back. During the 60's to early 70's GM "chromed hubcaps" were a disaster. Should have been made out of much stronger stainless steel like Ford used in there same era trucks. There is a thread on it. http://67-72chevytrucks.com/vboard/s...cap+metallurgy . I can add on to this topic. Some manufacturing plants started using chromed over steel in '73 and possibly some late '72's. There are very strong and very shiny and very rare. The only chrome hubcap a magnet will stick to. Heavier also. Magnet will not stick to the original chrome over brass, just not enough metal. The basic transition to the stronger stainless steel began in '72, but there are some that were built with older chrome over brass till supply ran out. But, there is a possibility, sooner or later you might eventually run into a steel painted hubcap that was stripped and chromed by the owner, not by GM.

[factorystock]

Originally Posted by factorystock

Some manufacturing plants started using chromed over steel in '73 and possibly some late '72's. There are very strong and very shiny and very rare.

Here is one of those rare '73 chrome over steel hubcaps. Not mine. Yes, they are getting pricey.https://www.ebay.com/itm/29604324231...Bk9SR4Kj9t_4Yg Most all gold bowtie '73-'75 caps are stainless, and just don't shine the same way as the rare chrome version.

[chevmn]

My experience with old cars and trucks, and in this case hubcaps has taught me to never say "they never made.....(insert phrase here)". Buying, swapping and selling I have seen about every combination above, and had most combinations mentioned, chrome over brass, chrome over steel and chrome over stainless, in both blue and gold bowties. But, here is an oddity, and feel free to jump in if you have ever seen one like the center cap in the photo, and what the application would be. At first glance (to me) it looked like a typical C10 cap, at least the center stamping, but looking closer it is a 12 inch diameter cap, but shallow - same depth of a 1/2 ton cap. Stainless and very much appears to have factory paint). I have placed it between a K20 and a C10 for reference in the photo. Obviously it would never work on a 3/4 ton rear axle nor a "normal" 1/2 ton wheel. I know it is difficult to tell detail and this site does not lend itself to zooming in. Ideas?

[factorystock]

Originally Posted by chevmn

But, here is an oddity, and feel free to jump in if you have ever seen one like the center cap in the photo, and what the application would be.

First issue '69 3/4 cap. Mainly used on front, but could be used on rear with non spicer axle.

[71CHEVYSHORTBED402]

Originally Posted by factorystock

Here is one of those rare '73 chrome over steel hubcaps. Not mine. Yes, they are getting pricey.https://www.ebay.com/itm/29604324231...Bk9SR4Kj9t_4Yg Most all gold bowtie '73-'75 caps are stainless, and just don't shine the same way as the rare chrome version.

Nicest looking finish of all - for a while

[DeadheadNM]

Thanks Dale!

Thanks for posting the link. It’s. Not clear to me on the post if that cap was factory painted or not - I’d like to see better pics. I could imagine a transition during 69-72 to stainless. So it seems fair to say that not all 69-72 “chrome” caps (and perhaps for 72 only) were indeed chrome with at least some stainless.

I’d still like to see some chrome over brass 69-72 examples. I see caps advertised for sale as chrome and I’m now asking myself how do sellers know for certain?

Here are 1/2 t caps. Spot the chrome example. One was NOS painted that I had chromed. Am worried the chrome will flake the first time I pry it off. Will see. The other is polished stainless. FWIW the painted examples I used were noticeably heavier than similar stainless. Maybe a true chrome cap weighs more than stainless?

[Joesjunk]

I have several nos chrome over stainless 3/4 ton caps at home. And I believe 2 chrome steel ones. I’ll have to dig them out and get some pics

[Joesjunk]

Here’s an NOS 69-72 chrome cap. I also have early yellow bow tie chrome over stainless caps.

[weim55]

Originally Posted by Joesjunk

Here’s an NOS 69-72 chrome cap. I also have early yellow bow tie chrome over stainless caps.

Do you think these are chrome over brass? Is the yellowing I see on the underside some of that brass showing?

Steve weim55 Colorado

[Joesjunk]

Originally Posted by weim55

Do you think these are chrome over brass? Is the yellowing I see on the underside some of that brass showing?

Steve weim55 Colorado

Steve, I believe that’s brass you are seeing.

[DeadheadNM]

Joe thanks a ton. The visible brass is a dead giveaway. When I get the chance I’ll post up pice of a blue bowtie NOS cap I have that is probably stainless as there is no visible brass. Would be great to learn when the caps were transitioned to stainless. Certainly by the 72 model year at least some were stainless not brass. There’s also a belief that some yellow bowtie caps are chrome. I’d like to see some proof of that. Wouldn’t seem to make much business sense to use a mix of chrome and stainless over many model years.

[Joesjunk]

Originally Posted by DeadheadNM

Joe thanks a ton. The visible brass is a dead giveaway. When I get the chance I’ll post up pice of a blue bowtie NOS cap I have that is probably stainless as there is no visible brass. Would be great to learn when the caps were transitioned to stainless. Certainly by the 72 model year at least some were stainless not brass. There’s also a belief that some yellow bowtie caps are chrome. I’d like to see some proof of that. Wouldn’t seem to make much business sense to use a mix of chrome and stainless over many model years.

They did make chrome yellow bow tie caps. I have several nos ones of those

[oem4me]

Originally Posted by DeadheadNM

There’s also a belief that some yellow bowtie caps are chrome. I’d like to see some proof of that. Wouldn’t seem to make much business sense to use a mix of chrome and stainless over many model years.

I agree that the mix of materials seems silly.
The cap shown below is chrome over steel. Besides being much shinier than stainless, there is visible rust on the backside, and a magnet sticks tight. Proof!
Now I suppose this could have been a painted cap that was chromed once upon a time, but the paintwork (despite thinning and wear) looks factory.

[IronCanine]

Originally Posted by oem4me

I agree that the mix of materials seems silly....

May seem silly, but it may be what happened. Do we know who made the caps? I assume (dangerous phrase I know) that these caps were made by a supplier (as many components/subassemblies were) and shipped to the assembly plant. It doesn't seem crazy to me that there might be more than one facility/supplier that was stamping out caps and that their processes might differ during overlapping time periods. For goodness sakes Camaros of this era were put together completely differently at different assembly plants during the same model year. I'm not saying that's what happened. But as you guys build the evidence here, that may be an explanation that fits.

Another killer thread regardless. Good on ya Pete!

[factorystock]

'69-'72 GMC 3/4 ton chrome over brass vs '73-'75 stainless. Note how the back side of the original chrome over brass discolors to a darker shade vs. stainless which stay pretty much as clean as the front side. It also appears to have slightly different block lettering that is found on the '73-'75 versions and paint is more reddish than orangish used in '73-'75 era. Not mine

[DeadheadNM]

Joe thanks again. FWIW here’s a blue bowtie NOS 3/4t cap I have that’s stainless w no visible brass.

[Joesjunk]

Originally Posted by DeadheadNM

Joe thanks again. FWIW here’s a blue bowtie NOS 3/4t cap I have that’s stainless w no visible brass.

I have 2 more nos blue bow tie caps I’ll have to dig out and see what they look like

[factorystock]

The brass spots showing on the back side is a dead giveway its an original chrome over brass cap. I've never seen a chromed steel hubcap with the blue bowtie in the convex configuration, all the chromed steel hubcaps I 've seen had the gold bowtie with the convex sharpe, but most gold bowtie hubcaps are stainless.

[hooverfish]

Originally Posted by DeadheadNM

Joe thanks again. FWIW here’s a blue bowtie NOS 3/4t cap I have that’s stainless w no visible brass.

Guess we sometimes have different opinions, and I'm not trying to disagree.... but ….
That 3/4T hubcap sure looks chrome to me. That dingy brownish or goldish color
on the back side does not look stainless to me.
However, I don't know how to be sure either way.
Think this GMC cap is chrome for sure … well almost sure ? ?

[DeadheadNM]

Originally Posted by hooverfish

Guess we sometimes have different opinions, and I'm not trying to disagree.... but ….
That 3/4T hubcap sure looks chrome to me. That dingy brownish or goldish color
on the back side does not look stainless to me.
However, I don't know how to be sure either way.
Think this GMC cap is chrome for sure … well almost sure ? ?

I’ll try to get a better pic side by side with a nos 1/2 t example for comparison. Would be thrilled if it were chrome but up close looks to have some “grain” on the polished side. I think the overhead garage light is imparting a yellowish hue.

Would like to dial in a for sure way to tell chrome apart from polished stainless. Pics of more chrome examples might help. I’m stumped on yours.

[FirstOwner69]

Here are pictures of one from my '69 3/4 ton. Not NOS like some of them here, but I am 100% certain it's original to the truck (Dec, 1968 production). It looks stainless to me. Not sure how to find out without scratching it on the backside with a sharp object. The weight is virtually the same as (about an ounce heavier) a similar yellow bow tie version I have.

[NewBayColony]

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[jamie72]

anyone got any tips on reapinting these caps after polishing?