YHM Clamp-On gas block installation??

[GI_Jared]

I did a search and didn't find anything but people arguing over what type of gas block should be used. So here is my issue.

Next weekend I plan to build my first AR upper. The type of gas block I am using is a Yankee Hill Machine (YHM-9384) low profile clamp on gas block. My plan is to loctite the allen bolts with some of the new high temp (up to 650 degrees) products that were just released. So I have two questions; How hard should I torque down the allen bolts on the gas block? , and What strength loctite should I use? The blue breaks at 102 in lbs and the red breaks at 161 in lbs.

FYI, the instructions on the YHM website just say "firmly tighten the pinch screws and re-check alignment"

Here is a pic of the gas block
http://yhm.net/images/YHM-9384.jpg

[GTifosi]

Torque depends on the screw diameter and pitch. Gotta be a list out there somewhere to bounce #'s off.

As for loctite, there's not much sense going for the 161 in/lb stuff if the screws will fail anyway at anything above 110 in/lb anyway.
At least if you ever want to mabe remove them without resorting to a lot of heat and thread chasing after.
The stuff only needs to be stout enough to hold the screws from coming loose due to heat expansion and/or vibration, not make a permamant fixture out of them.

Think of it like staking, jam nuts or urolock nuts, not tack weld, taper pinning or blind pinning.

[jet80tv]

I wouldn't even follow YHM's torquing instructions for their products, they don't even recommend a torque value or using a torque wrench on their barrel nuts.

[ache_d]

I would consider using Rocksett. (Google it) It is a thread lock adhesive like your usual Lt's but it is designed for the extreme. -300 to 1200 (F) but don't quote me on that exactly. Then use an automatic punch pin to stake it.

Or..... send it to ADCO and have it pined in place. If it is under the handguard I wouldn't be tooooo concerned with it if it isn't getting any direct contact.

Good luck on your build! Be sure to post pics!

[archad]

If you plan on using this under a FF rail you might want to get another gas block. It will touch slightly on a Troy TRX rail. I had a Rainier Arms 12.37" handy and it clears the YHM clamp on gas block.

[Suwannee Tim]

I would consider using Rocksett.... Then use an automatic punch pin to stake it......

Do you mean a center punch? You don't seem to know the terminology.

Just blue Loctite the thing, if you want to use a torque wrench, 50 inch pounds is about right for a 10-32. That way you will be able to get it off if you want. If you are not sure the screw size, a 10-32 is about 3/16 and fine thread pitch.

If you are worried about coming off, I wouldn't. I have a clamp on Adams piston kit on a rifle with 6K rounds and counting, no movement yet. I torqued the screws to 40 inch pounds, kind of light on the torque, and no thread lock compound. I wanted to see if it would move. It hasn't.

[archad]

http://www.google.com/products/catalog?q=automatic+center+punch&um=1&ie=UTF-8&tbm=shop&cid=6629772858293869384&sa=X&ei=UO0UT9-7HO6AsgL9otT1Aw&ved=0CGYQ8wIwAw

[ache_d]

Do you mean a center punch? You don't seem to know the terminology.

:nono:


Ill Dumb it down for you with an instructional video. http://www.youtube.com/watch?v=TsY8U4exqOE&feature=related you can learn something tonight, Suwannee Tim. And you CLEARLY know a lot less than "terminology" get your stuff straight man!! LOL .... And good lookin' out archad!

[Suwannee Tim]

:nono:


Ill Dumb it down for you......

You are a poseur and a troll son.

[mkmckinley]

Ill Dumb it down for you with an instructional video. http://www.youtube.com/watch?v=TsY8U4exqOE&feature=related you can learn something tonight, Suwannee Tim. And you CLEARLY know a lot less than "terminology" get your stuff straight man!! LOL .... And good lookin' out archad!

I'm not trying to stoke the fire but your response is over the top. The video you posted clearly states the tool you were referring to is called an automatic center punch, not an "automatic punch pin" as you called it. ST was simply pointing out the error IOT make the thread useful for anyone reading. Instead of getting defensive a simple "thanks for catching my mistake" will do. Check your tude, it's not going to get you anywhere here.

[ache_d]

Yeah I hear yah MKM. Lol i reread that today and I did bring some intensity to that haa. But most knew what I meant. My B!

[GI_Jared]

If you plan on using this under a FF rail you might want to get another gas block. It will touch slightly on a Troy TRX rail. I had a Rainier Arms 12.37" handy and it clears the YHM clamp on gas block.

Yep, FML.... I got my barrel in today and did a test fit of the barrel, gas block, upper, and my Troy Alpha rail. It touches ever so slightly on the bottom of the gas block. I am going to try and remove some material from the gas block along the bottom to see if I can get it to fit. If that doesn't work I will just turn a standard front sight base into a lo-profile gas block which is probably what I should have done in the first place.

[archad]

That is what I had to so I could find a use for the Troy TRX it is on a 14.5" BCM middy.

http://fototime.com/21C8BA04CE1EED6/standard.jpg