Winch Shear Pins

[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.

 

[m16ty]

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.

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]

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.

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.

 

[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.

 

[emmado22]

It just seems like alot of work when Saturn Surplus has them for $3.50 each instock....

 

[cranetruck]

I know Mark, you are practical to the Nth degree, but that takes all the fun out of it, IMHO.
These kind of discussions often lead to new things.

 

[Recovry4x4]

I get them from Gene Patano for $2 ea in lots of 10 or 20. Original GI issue.

 

[m16ty]

It just seems like alot of work when Saturn Surplus has them for $3.50 each instock....

I feel sure if I can find the temper I can cut them out of solid rod and drill two holes in it for less than a $1 a piece.

 

[Willie G]

Just a quick safety note: PLEASE remember that doubling or tripling the line magnifies the load on the components and they should be rated accordingly. In other words, a 8,000 lb winch in a double line pull could have 16,000 lbs of force - which would require a snatch block rated for more than that as well as attachment points that exceeded that. I carried clevises and blocks rated for 20,000 lbs for the 9,000 lb winch on my Jeep.

We now return you to your regular progamming.

 

[gringeltaube]

For do-it-yourselfers or the ones who can't buy them so cheap or aren't so close by....
I just did some comparative testing with my own creation of a "shear-pin cracker" (pat.pend. ) which actually worked better than expected.......

The OEM pins (including the broken core of my very 1st winch miss-hap...) snapped at about 160 ft-lb. More or less the same torque was needed for a home made one made of brass which I had used for years of "normal winching action" but later replaced when I found it with already some deformation.

Also I have a few larger ones of unknown application...(the M35 uses 0.279" x 2.125" measured inside cotter pin holes, these are 0.329" x 2.25") so I turned one down and it also took 160+ to shear it.

For comparison another "homemade" pin of unknown alloy but at least showing some temper... only resisted 100 foot-pound!

Next step will be trying to find 2024 or 2017 alloy locally and compare different levels of temper.
At least I know now what the goal is....

G.

 

[emmado22]

The bigger ones could be from 5 ton winch trucks??????

Wh doesnt someone call Garwood and see what THEY have to say about it??? What would they know, they only built the things.....

Garwood Feller Inc (Garwood Winch Div)
1820 Osborne Rd, Saint Marys, GA 31558-9104
Contact Phone912) 882-4151 URL (web address):
Business Category:Mfg Construction Machinery Mfg Motor Vehicle Parts/Accessories in Saint Marys, GAIndustry (SIC):Construction Machinery and Equipment

 

[Oldgrunt]

Does any one out there have the resources or know of someone that could find out what alloy the shear pins are made of. From what I understand there is a special machine something besides a rockwell machine to test softer alloys. If the alloy could be found out making replacement pins or ones that would with stand a little more, would be easy.

 

[m16ty]

Does any one out there have the resources or know of someone that could find out what alloy the shear pins are made of. From what I understand there is a special machine something besides a rockwell machine to test softer alloys. If the alloy could be found out making replacement pins or ones that would with stand a little more, would be easy.

The pin I tested (which is a surplus pin) was 2024. The temper is what's in question now.

 

[cranetruck]

To aid your research, use the NSNs.