Tow Hooks: Post your foundry casting marks

[DeadheadNM]

I'd like to see detailed examples of the foundry casting marks present on tow hooks for 67-72 trucks. Curious what's out there. These marks can serve as supportive evidence of an OEM part in the absence of part numbers, such as the case with some (most?) 72-only tow hooks. Perhaps for this style one foundry included part numbers but another did not.

Here's a borrowed example that shows what I'm after adjacent to the part number but it lacks detail enough to really identify the mark.

[MJN]

Those marks are present on my hooks, not the best lighting with glossy paint but hopefully you can make them out. One hook is more pitted than the other but you can still make out the faint outline of the mark by the part number. Got these out of the junkyard- off an early 50's GMC COE grain truck, the yard owner just looked at me funny and said if you can get them off go for it.

[Graham57a]

Here’s the best pic I could get of mine. Almost looks like a U with a hexagon around it

[too much stuff]

First is an extreme without a part number, second is a 69-71, third and fourth is a 67-68, and last is a pre 67.
Some extremes have part numbers, some don't. Certain extremes seem to have fine thread bolts also if I recall correctly.

[Bones72Super]

Great thread Pete, however these hooks are forgings not castings. I could be wrong but I would think in a shock load scenario GM would use a forged unit over a cast unit.. Castings have incredible compression strength but don't do well under tension/bending/leverage. Just thought I would point that out, not trying to nit pick or bash

[DeadheadNM]

Great point. I’m sure you are correct. I’d like to learn more about the manufacturing process. Am envisioning some molten steel poured into a mold.

Here’s a set of 72-only I have on the shelf. Look like a circle (or a worn hexagon) with a “U” and no part numbers.

Thanks for posting. Let’s see some more.

Edit: quick video here reviews basic differences between forging vs cast techniques. I have a lot more appreciation for these forged pieces: https://www.youtube.com/watch?v=H9qTcAyMuPU

[Chevyland]

72 extreme bends
With
Foundry
And
Part #

[Chevyland]

Another set of extreme’s
With foundry markings
But
No part number

[Bones72Super]

[QUOTE=DeadheadNM;8759996]Great point. I’m sure you are correct. I’d like to learn more about the manufacturing process. Am envisioning some molten steel poured into a mold.

Pete, have a gander at this wonderful video from the 50's. You will have a good understanding of the process and benefits of forged products. Plus there is some amazing equipment and machinery that is just plain awesome

https://m.youtube.com/watch?feature=...&v=v2_0V58ocq4

I fixed the link, it should work now

[Killer Bee]

Originally Posted by Bones72Super

Great point. I’m sure you are correct. I’d like to learn more about the manufacturing process. Am envisioning some molten steel poured into a mold.

Pete, have a gander at this wonderful video from the 50's. You will have a good understanding of the process and benefits of forged products. Plus there is some amazing equipment and machinery that is just plain awesome ��

http://Watch "FORGING HISTORY VIDEOS...be/v2_0V58ocq4

I did some work in Shultz Steel some years ago.. they asked us to speed up the machines that moved steel from the furnaces to the presses.. scale size of this place is nothing short of amazing! the parking lot would shake when the big presses were running.. had a great time working in there several days.. cranked up the hydrostats on their specialized handlers.. they were hauling azz in there with giant chunks of steel glowing almost white and bright as the sun!

http://www.shultzsteel.com

some pictures here http://testshultzsteel.com/Equipment/Capabilities.aspx

check out what they have now

Huge hydraulic press goes to work in California

[IronCanine]

'71 Flint Blazer. Not great pics, tried to sharpen them a bit.

[DeadheadNM]

Interesting that so far these all have a “U” logo/mark. That denotes a particular foundry - I wonder which?

Also, it seems as though the non-part numbered 72s have a mark featuring more of a circle rather than a hexagon.

[dennislbrooks]

Same casting mark as Deadhead and others.



p/n 3663349-50


http://67-72chevytrucks.com/vboard/s...d.php?t=708395


Frontwards , backwards, right, wrong -- supposedly these correct 60-68 tow hooks in my opinion are overkill for a 1/2 ton or 3/4. I bought the pair and they had what I think are the original 5/8" grade 8 fine thread bolts and I mounted them with 4 new grade 8 coarse threads with the thick washers and lock washers on the inside. I used 69 front leaf spring hangers --I do not know if they differ in design of a 67 K10 but there was little room for mounting them on the frame.

As I said earlier they both curl the same direction which is not noticeable but either correct or incorrect. If anyone has a pair of p/n 363349-50 that curls opposite mine I will trade you one.

There is no gm info I can find and it appears that 67-72 has more info -right or wrong- on them than anywhere on the web. My assembly book does not show them at all.

[Killer Bee]

Originally Posted by DeadheadNM

Interesting that so far these all have a “U” logo/mark. That denotes a particular foundry - I wonder which?

Also, it seems as though the non-part numbered 72s have a mark featuring more of a circle rather than a hexagon.

last time this came up, I searched thoroughly but could not find Hex U listed but several others here with logo pictures of this type of marking..

Alloy Artifacts - Trademarks and Logos

from browsing that site, they don't seem much interested in taking on our query but maybe a smooth talking rep could get one their researchers on the case..

had these pictures handy of a couple pair of regulars..

I'll try to get better pictures of these and the extremes I have..

[tristan]

Extremes. Both curved in the same direction so same part #.

[tristan]

1969-72 non-extremes. Not curved in same direction so different part # on each.

[57taskforce]

Cool thread Pete... I need to round a set up for my truck.

[Ol Blue K20]

Here's mine, no part #'s on these extremes. Great thread Pete. Cool video too. I never thought I would learn something from a golf video....lol

[DeadheadNM]

Bones - I’m awestruck at the content in those films. Thanks for posting. Amazing. I’ve got a lot of admiration for those steel workers and grateful to have real forged examples.

Here’s a rear tow hook shot from the first film.

Thanks for posting guys.

Killer I’ll check that out here shortly. Too cool. BTW the US Patent office likely has this forge mark/logo in their searchable data base. Looks like the searches are somewhat convoluted but I’ll give it a go when possible.

[davischevy]

These have the marking, but no part number. Notice the white paint.

[farmall]

The octagon with the letter inside was American Steel Foundries with the letter being the location of the city or branch.

[DeadheadNM]

Originally Posted by farmall

The octagon with the letter inside was American Steel Foundries with the letter being the location of the city or branch.

I noticed that when I stumbled upon a list of WWII era foundry marks but those here are hexagons so not certain it’s the same company. Example list here: http://web.inter.nl.net/users/spoels...04/foundry.htm

[davischevy]

Did American Foundries have a location the started with a "U"?

The Hex symbol sure points to them, but that Registry doesn't show a "U" location.

[dennislbrooks]

73-80 tow hook casting -- Same U

328072

[Killer Bee]

borrowing pictures of these I just bought from Ironhorse, hope he doesn't mind





they match the profiles of the fronts perfectly so maybe some genetic relationship although they have different forge marks..

took these close up pictures of part numbers and logo but C or Horseshoe X doesn't seem to match the marks we've discovered so far..

maybe Keith knows someone from the plant who would have some leads?

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