Staking a hammer strut pin

original: thehighroad.org
Retrieved: November 21, 2011
Last Post: March 22, 2004

gharsh
March 10, 2004

I want to change out a hammer on one of my 1911's and noticed that the strut pin is in there pretty good. I looked in Kuhnhausen's book and it says that the strut pin should be staked to keep it from coming out. Well, two things: 1. Can I just punch out the pin? 2. Do they have to be staked in the new hammer, and if so, how?

I am thinking of just getting a new hammer strut and pin and putting it in the new hammer without using the old one, but if I can use the old one I will.


Clemson
March 10, 2004

Yes, you can punch out the old pin. The staking just keeps you from losing the pin. It is captured when it is installed, so staking is not technically necessary.


1911Tuner
March 11, 2004

Here's my method.

I install the strut and the pin. Lay the hammer on its side on a piece of flat stock... cold rolled will do... and use a sharp center punch to punch the pin in the center. This expands the pin and makes for an interference fit in the hole. Flip the hammer over and do the other end, then flip it back over and re-punch the first one again. The ends will expand enough to keep the pin from falling out, but will knock out easily if the need arises. The pin can be used again by repeating the operation.


gharsh
March 11, 2004

Thanks for the assistance. The problem I noticed is getting the old pin out. I didn't want to bang away too hard, but it seemed like it needed it.


Jim K
March 14, 2004

Tuner's method has the advantage of not affecting anything but the pin, but the pin is enlarged and can enlarge the hole if/when driven out. The normal way of staking is to radius (round) the end of the pin slightly and then use the punch on the area immediately adjacent to the pin, driving a bit of metal over into the pin hole. The same method is used to stake the barrel link.

As Tuner says, though, both pins are captured when in the gun, so they can't come out. The reason for staking the pins is simply to keep them from falling out when the gun is disassembled. (It is highly irritating to take a 1911 type down and have the strut pin or the link pin fall out and be lost. Ticks one off.)


gharsh
March 16, 2004

Well, I've got the pin in, put the gun back together. New hammer works. But, my thumb safety does not "snap" into place as it did before the new hammer. Is there something that needs to be tuned, or just worked into place. It works, but it takes more effort to get the safety engaged.


1911Tuner
March 16, 2004

The safety blocks the sear, and if the sear's depth of engagement in the new hammer is different, it will affect the way the safety lug engages the sear. It only takes a tousandth of an inch or two to make a difference. The lug on the safety probably needs to be relieved a little(refitted) so that t can be moved into position.

To see where the interference is, assemble the gun without the grip safety and move the thumb safety up and down while watching it with a penlight. It will be a trial and error exercise. A little makes a big difference. If you remove too much metal from the engagement surface, your safety may not block the sear correctly. Go slow.


1911Tuner
March 17, 2004

Jim said:
Tuner's method has the advantage of not affecting anything but the pin, but the pin is enlarged and can enlarge the hole if/when driven out

Very true, but I don't deform the pin more than needed for a light press fit, and when time comes to remove it, I can usually push it out without needing a hammer, or at most, with a light bump or two. As long as the pin doesn't fall out of its own weight, I'm a happy camper. Pins is cheap... Hammers isn't.


Old Fuff
March 17, 2004

I have staked both pins (hammer & link) but prefer to make an oversized pin and press fit it. Thereafter I never had one move - unless I moved it. In theory the larger pin could bind the link or hammer strut, but in practice it's never happened.


1911Tuner
March 17, 2004

Old Fuff said:
I have staked both pins (hammer & link) but prefer to make an oversized pin and press fit it.

There ya go! I quit staking link pins a long time ago. I'll install a .156 pin, and finding that it's not a tight enough fit, will ream and make a pin out of drill rod. Why? Once a link pin has gotten loose, it will start pounding the hole into an egg-shape, and linkdown timing gets outta whack.


gharsh
March 18, 2004

I plan on taking a look at it on Friday and will post again if I run into snags. Sounds easy enough. Go slow, a little makes a big difference... words to live by.


gharsh
March 22, 2004

On Friday, I was able to get around to working on the safety and got it fixed. Just took a little off and squared up the surface.


Stinkyshoe
March 22, 2004

Do you have to stake any of the pins in the 1911? Do the Hammer and sear pins need to be? If the pins seem to a little loose in the frame, but the pins are the correct dimension, what can be done to eliminate the problem?


1911Tuner
March 22, 2004

The hammer and sear pins don't need to be staked. They're supposed to be a slip-fit so that the gun doesn't require tools to detail strip. If the pins wobble in their holes, they should be replaced with new pins, or if that doesn't clear it up, oversized pins. Reaming the holes to size may be required. Unless your holes are worn badly, this normally isn't required, assuming that the holes were out-of-spec(large) to begin with.


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