Removing an ornery small set screw?

josquin

josquin

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I recently acquired up a used Springfield 1911 .45 Hi-Cap. The rear sight is secured by a small set screw that is seemingly immovable. I've been soaking it with Kroil and occas. tapping it gently with a small brass punch before trying to turn it with a 1/16" hex wrench- which is now twisted :eek: The only other thing I can think of is to try applying localized heat by putting the soon-to-be-toast hex wrench in the screw and heating the wrench with a propane torch to get a little thermal expansion and contraction in the screw.

Any other suggestions?

:) Stuart
 
Instead of just prying on the allen key, tap on it. (like a little impact wrench)

You can also heat the area, screw and all, with a mini butane torch. Although this will discolour the bluing in that area. Heating the allen key itself will just soften the key, making it completely soft and useless. You would need a second "good" one.

I don't think a soldering iron will get it hot enough. Also you would need a little solder on the screw for heat transfer.

If the screw has loctite on it, you will need heat.

Also, try using the OLD formula Break Free, I believe Marstar has it.
 
Thanks for the suggestions. I realized after posting that I would need more heat than heating a small Allen key would provide. I have a small butane torch so I can have a go with that. Quite possibly a previous owner may have applied Loctite.

As to penetrating liquids, I remember reading a post somewhere where a test had been done on various products and Kroil came out near the top of the list, but there was one other product that topped them all. As I recall it may have been automatic transmission fluid; I think it was one of the components of Ed's Red. Must try to find that info somewhere.

:) Stuart
 
cut off your twisted allen key and use it as a punch.
use that butane torch to heat the screw heat,they concentrate heat well.
relieve the screw with the "punch" and a blow from a small hammer.
you can also heat it and apply penetrating oil as it cools.should draw it down into the threads.
we used to use brake fluid as penetrating oil in the wrecking yard.
 
If you have a spare allen key put the twisted one into the screw and apply LIBERAL heat to it. The heat will travel down the screw thus localizing it.
Use your good wrench to then back it out.
 
...WHILE it is still hot.

I know it seems to follow logically but I knew of someone that waited thinking that the heat had destroyed the Loctite and that the screw should turn out when cooled down. He didn't realize that the Loctite got hard again as it cooled.

Use your newly twisted off allen key for the heat transfer.
 
Well, I had another go at the little b****r and it's still stuck. I applied as much heat as I dared - hot enough to soften Loctite, I think - having removed the extractor & firing pin and clamped the slide in aluminum jaws in my vise. (I kept a finger on the underside of the slide to see how hot it was getting underneath.) I applied the flame directly to the screw head, inserted the hex wrench, tapped it, turned it, heated the hex wrench etc. as suggested. but it still refuses to budge. I don't know what's holding it in there but it's very successful!

Fortunately the sight is only ever so slightly off-centre but eventually I'd like to be able to move it. I fear I may have to cut the sight out and install a new one, which is an expense I was hoping to avoid.

The dovetail appears to be .330 x 65 deg. I have no idea whose sight it is:

1911%20sight%20left.JPG
Sight top sm.JPG

although it's possible it's from King Gunworks as I think they have a similar one. It and the .180" front sight form a 3-dot set. I'll look into my options but getting something that will fit that dovetail and not require a higher front sight may not be so easy. I'm really out of practice but it seems to shoot a little high and a tad to the left with the 200 gn. bullets I have on hand.

:) Stuart
 
Drill the set screw out undersize. I suggest taking it to someone with a milling machine, it may not be some you want to do with a hand drill or a CT drill press.
 
Hmm, looks like you're having quite a go at it... I can sympathize having spent many a while trying to free stuck parts without causing damage.

A couple of ideas:

1) Repeat the heating procedure, but try turning the set screw in the "tighten" direction to see if it moves. Sometimes going in the opposite direction slightly can help break a tight bond. I don't think you have to be too concerned about the amount of heat you're using as long as the metal is not discolouring.

2) Try an allen screw insert on a regular screwdriver handle. You ought to be able to get some extra torque that way.

3) Carefully drill out the center of the set screw being careful not to go so deep as to cut past the tip. Tap a screw extractor into place (the square kind), attach a pair of vice grips to the extractor for leverage, and try to remove the screw. Drilling out the screw can relieve some pressure off the threads and the extractor is often stiffer than an allen key so can allow you to torque a bit more. Take extreme care, though, not to break the extractor.

Good luck and hope you figure it out.
 
heat and repeat.
the metal around the screw is likely acting as a heatsink,and any discoloration will be on the sight itself from the looks of things.
you need to give it a descent whack to break it free,and not on the head as the shoulder will take the force.If you don't want to cut your allen key for a punch use a small punch that will fit in the screw head.
I've removed screws that have been in place over 100 yrs with this method on antique revolvers and only had 1 failure.

what are the odds that the screw is b!tched and that's why the sight is off center?have you tried moving the sight in the dovetail?
Do you have a deadblow hammer?

drilling it out is a last resort imo.
 
Thanks for the ongoing support, folks.

I have tried turning the screw in the other direction as well, with no luck. And the sight will not budge. I don't think the sight is off because of the screw but who knows? I haven't tried a deadblow hammer; I've been using a small ball peen. I'll move up to the 16oz one next. As they say, "If all else fails, use a larger hammer." :eek:

I'll be looking for a hex bit insert when I'm at Hardware Sales in Bellingham :D tomorrow. A really rigid, stubby hex bit might just do it. As a last resort I may drill it out. I'd need a very hard short bit such as a carbide centre drill but HS probably has those, too. (My HS centre bits won't be hard enough on a set screw.) I may end up having to recut the threads on the sight as well.

Just another of those darned "learning experiences."

:) Stuart
 
Use a impact screw driver after you apply the heat. You will have to find a vise and wrap the firearm so it is not damaged, put the impact screwdriver in and give it a good rap with the hammer the screw will not have much choice but to come out. If you do have to drill out the screw use a reverse drillbit at low speed the screw will usually back out stuck on the drillbit.
 
Josquin, if it comes down to drilling out the screw you can do it with a regular HSS drill bit. The setscrew isn't THAT hard. I hacksaw and file down grade 8 screws to shorten them for various bicycle and other projects all the time. Including drilling them now and then.

And I suspect you didn't heat it anywhere near as much as you think you did. Assuming it is loctite and not a burr under the sight then the screw and sight will need to get hot enough that water flicked onto it will sizzle like being dropped into a hot fry pan. You cannot hold or touch something that is up around 230F to 250F degrees anymore than you can touch boiling water and not get burned.

Did you try drifting the sight already with the screw stuck? If so then drift it back. The tip may be solidly wedge by the burr it likely plowed up from the bed of the dovetail. Knocking it back a few though may reduce the wedging action if it did pull up a burr.
 
BCRider said:
...And I suspect you didn't heat it anywhere near as much as you think you did....
Click to expand...

I didn't try the water test but I had a fine-tip propane torch on it for a while. The slide was clamped between aluminum jaws in my vice so that would soak up a fair bit of heat. Maybe I can tell if it gets too hot when the white sight paint on the two dots begins to discolour :eek: (Actually, they are a tad less white now, but I have sight paint.)

If I don't need a carbide bit, so much the better. (I'm still going to Hardware Sales, though. The car drives itself there anyway. so it's out of my hands.)

:) Stuart
 
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