Loctite on S&W thumbpiece nut?

[Carmady]

Do any of you use Loctite on the S&W thumbpiece nut? Any reason not to?

[DaveJames]

Have done it for years on the 357-44 mag guns, VERY LITTLE is needed

[Carmady]

Thanks.

[Aguila Blanca]

Which Loctite?

[Carmady]

I used blue 242. I'll try purple if blue doesn't work, since it's a small screw size.

[1MoreFord]

Ooops, too late.

[1911_Hardball]

Originally Posted by Carmady

I used blue 242. I'll try purple if blue doesn't work, since it's a small screw size.

Purple is lower strength than blue.

[Carmady]

Purple 222 is for fasteners from #2 to 1/4" (2.2-6mm)

Blue 242 is for fasteners from 1//4" to 3/4" (6-20mm)

I had 242 fail a few times on the thumbpiece set screw/hinge pin on a LCR. It kept backing out on range day.

[Aguila Blanca]

If 242 (Blue) won't hold it, 222 (Purple) definitely won't hold it. What materials are the screw and the sight? Loctite needs primer activator for some metals, a fact I learned just a few days ago.

[1911_Hardball]

Originally Posted by Carmady

Purple 222 is for fasteners from #2 to 1/4" (2.2-6mm)

Blue 242 is for fasteners from 1//4" to 3/4" (6-20mm)

I had 242 fail a few times on the thumbpiece set screw/hinge pin on a LCR. It kept backing out on range day.

Right regarding the sizes, but the manufacturer lists 242 as "medium strength" and 222 as "low strength".
It's important that with any application that the threads be free of grease/oil.

[Stroker468]

I used blue... holding after about 200 rounds through my 629.

[10-96]

Is your thumbpiece screw always loosening up. or is it stripped out? The reason I asked was I recently replaced one that had the threads badly messed up. I don't know if it was cross threaded during the manufacture of the screw or when it was put on the pistol- but either way, check to make sure something isn't wrong with it.

[Zzeke]

I use Loctite 243 on all things gun related. It is blue in color, and the same as Loctite 242(blue), but it is oil tolerant. The fasteners can't be sopping wet with oil, but it will still work with an oil film, where 242 will not.

[Zzeke]

I use Loctite 243 on all things gun related. It is blue in color, and the same as Loctite 242(blue), but it is oil tolerant. The fasteners can't be sopping wet with oil, but it will still work with an oil film, where 242 will not.

[Carmady]

"Right regarding the sizes, but the manufacturer lists 242 as "medium strength" and 222 as "low strength".
It's important that with any application that the threads be free of grease/oil."

I always clean the threads with alcohol, lighter fluid, acetone, etc. With the LCR I went easy on the female threads because I didn't want to leave any traces of paper towel in there. The Ruger tech advised against Loctite, but use it lightly if necessary...that was to make it easier on them if they ever need to disassemble it.

Back to the low strength purple stuff, I was thinking it might also be a thinner mixture which would work better with the smaller threads. I've never used it, but will get some and try it on the 10 if the 242 blue fails and the thumbpiece backs off again.

Both male and female threads on the thumbpiece looked just fine.

I've seen a lot of buggered up thumbpiece nut slots on GunBroker.

[Aguila Blanca]

Originally Posted by Carmady

Back to the low strength purple stuff, I was thinking it might also be a thinner mixture which would work better with the smaller threads. I've never used it, but will get some and try it on the 10 if the 242 blue fails and the thumbpiece backs off again.

As has already been pointed out -- if #242 (Blue) doesn't hold it, #222 (Purple) absolutely will not hold it. The reason Purple is listed for small screws is because Blue is aggressive enough that the torque needed to remove it may shear off small screws.