The Firing Line Forums - View Single Post - Using Loctite when mounting M-223 on my Windham Weaponry SRC

Creeper · September 23, 2012, 12:34 PM

Technically... none of those Loc-tite products are correct for 1/4" and smaller, low torque value screws. The correct Loc-tite is 222 "purple"... which is not readily available at the local big box hardware store. Having said that, most folks have 242 "blue" Loc-tite on hand and will use that... which is OK.

The wick-&-lock or "after the fact" Loc-tite is called 290 "green" and can be used on sub 1/4" fasteners down to 2.2mm. Unlike 242 however, it may require heat to disassemble.

The most important thing is cleanliness and torque. All parts should be clean and grease/oil free. If you don't have one, get a inexpensive torque screwdriver like a Wheeler FAT torque screwdriver. Don't go over 20 in.lbs. on the rings, or 35 in.lbs. on the bases unless they are oversize tactical base screws... and even then, I would not exceed 45 in.lbs.

Cheers,
C

September 23, 2012, 12:34 PM	#2
Creeper Senior Member Join Date: September 9, 2008 Location: Woooooshington Posts: 1,797	Technically... none of those Loc-tite products are correct for 1/4" and smaller, low torque value screws. The correct Loc-tite is 222 "purple"... which is not readily available at the local big box hardware store. Having said that, most folks have 242 "blue" Loc-tite on hand and will use that... which is OK. The wick-&-lock or "after the fact" Loc-tite is called 290 "green" and can be used on sub 1/4" fasteners down to 2.2mm. Unlike 242 however, it may require heat to disassemble. The most important thing is cleanliness and torque. All parts should be clean and grease/oil free. If you don't have one, get a inexpensive torque screwdriver like a Wheeler FAT torque screwdriver. Don't go over 20 in.lbs. on the rings, or 35 in.lbs. on the bases unless they are oversize tactical base screws... and even then, I would not exceed 45 in.lbs. Cheers, C __________________ Shoulder Drive Nicholson Club