m16ty

I got a pin today ( thanks rockman). I should be able to find the alloy if I can hammer it out enough to get enough surface area to get a good test.

m16ty

I got the pin tested today. The alloy is 2024 and 9/32" in dia. for anyone that wants to make them. I'm thinking of maybe making them and offering them for sale myself if I can compete with the cost of surplus pins.

DanMartin

This is great info M16ty, but I think there's more to this we'd need to know before cranking out pins.

Is it 2024-O, 2024-T3, or 2024-T351? (The latter being heat treated versions of the 2024 alloy, 2024-O being not treated).

I'm not sure what tests were run, but the heat treating would make a difference in the yield strength of the pin (by nearly a factor of 2).

Here's a bit on 2024 alloy.

Dan Martin
1988 M35A2C (USAF)
1945 M29C Weasel
Hillsboro, OR.
MVPA# 31124
MVCCO# 828

We shall not cease from exploration
and the end of all our exploring
will be to arrive where we started
and know the place for the first time
- T.S. Eliot

m16ty

The test that was performed just told the alloy. The local scrap yard has a gun that you put it aginst the metal and pull the trigger and it tells the alloy on the screen. It has no way to tell heat treatment. I had to hammer the pin flat to get a reading on the machine and I can tell you it seem softer than most AL I've ever delt with ( I know, not very sciencitific ).

I'm thinking maybe I could get a piece of 2024 of the same dia. of the pin and drop a wieght from specified hieght on both and check the deformation of both after the test to see if they match (I'll know the heat treatment of the new AL). What do you think?

gringeltaube

What we really needed to compare is its shear strength.
I would take a ¾” bolt with its nut on, drill a 9/32” hole through both, clean and lube, stick the pin in, hold the bolt head in a vice, turn the nut with a torque wrench and read how much it takes to shear each sample.
This isn’t scientific but probably practical enough to be performed repeatedly anywhere in the world to help us select the material that comes closest to what you find for the OEM pin.

G.

m16ty

Better yet is you could find a rod close the the dia. of the winch input, slip a piece of pipe over the rod, drill through both for the pin, weld nut to pin, and put rod in vice. You could then use a torque wrench on the welded nut.

Only problem with my idea or yours is a "click" torque wrench isn't going to give you a reading at failure ( you may could just adjust it up a little at a time and make it work) and a "beam" wrench is going to be hard to read at the failure point. There may be a torque wrench that will store max torque applied but I've never seen one.

My line of thinking is now that we know the alloy there is going to be a noticable difference in hardness of the different heat treated 2024 rods so I'm still wondering if my "drop test" would work?

madsam

That is interesting. I thought those winches were stronger. I used a 9000lb marker winch on my old wrangler chained to a tree to pull my m816 up a steep hill. I know dumb people can destroy things, but I would think the winch should pull harder than that.

cranetruck

The shear pin determines the level of safety, not the strength of the winch.

This was mostly covered in previous posts, but my search now ends with a "404" msg....

There are also many PS magazine notes, also no longer available. The link in this search result is now a dead end.


"I did post the alloy some time ago, but "search" doesn't help me here. I had found the alloy except for the temper (T3, T4 etc)....

Found this after a lot of searching:
http://steelsoldiers.com/index.php?n...amp;highlight=

...... the alloy for the 260 series 5-ton winch (5315-00-209-7979), it is the 2017, probably -T4 temper, which has a shear strength of 38,000 psi.
It's a start..."

Interestingly, the same 5-ton winch for the m656/xm757 series 8x8 trucks specifies a copper alloy pin.

Bjorn
Virginia's Blue Ridge Mountains

(Link to PS magazines: http://old.steelsoldiers.com/index.php?name=gallery)

Avatar: XM757 in OK prepared for 1,000 mile trip home. Part of 6,000 mile journey in 2006.
1968 M49A2C modified with 1960 M756A2 truck bed and 1975 HIAB 765A knuckleboom. Heated dual tank system for biodiesel/veggie oil use.
1969 Ford XM757 8x8, 5-ton Pershing 1A truck tractor, the "improved" MV.
"Some things can't be made better, just differently......a lot of things actually"

WPNS421

My first post, new to this game. The winch has a higher rating than the weight of the truck and the shear pin is designed to prevent damage. If stuck to the frame of the truck the winch needs to pull the weight of the truck and also overcome the suction or obstacle. The total weight put on the winch doubles and triples when nothing moves. I have seen a tank stuck to the bottom of the turret in mud and it had 3 tank recouvery veh w/pulleys (100 + ton capacity combined)to pull it out.

WPNS421

Shear pins are not a problem with thee Cdn deuce, the front winchs are all hydraulic no shafts or pins. We tried ours yesterday. We have an M36C Cdn with a winch and a Hiab knuckle boom with a cable winch mounted on the Hiab. This truck was just purchased and we started it for the first time yesterday.