My Torque Values:
AR Compensator (Flash hider): No torque, timing value per the procedure in the Army TM. Hand tight, then tighten a minimum of 90 degrees but no more than 450 degrees to timing. Don't over tighten, don't loosen.
AR Barrel Nut: 30 ft-lbs minimum, not to exceed 80 ft-lbs to align the next slot in the barrel nut. The 80 ft-lbs isn't stated in the TM, but it's hard to line up the gas tube without going over 30 ft-lbs unless you use shims. This spec is common across the community and internet.
AR Carrier Key Screws: 50-58 inch-lbs
AR Lower Receiver Extension (Buffer Tube/Castle Nut): 40 ft-lbs for both Rifle and Carbine.
M-LOK Accessories:
- Metal to metal hand guards: 35 in-lbs
- Polymer or metal to polymer hand guards: 15 in-lbs
- Polymer to metal hand guards: 15 in-lbs
These installation values are recommended limits, not minimums. Nylon patch compound may slightly affect the torque reading on an in-lb wrench. Use a small hex wrench to help prevent over-tightening — the recoil lugs do most of the work, so excessive torque on the nuts isn't required.
A note on the rest: The additional research below couldn't be confirmed against the Army TM, manufacturer sites, or other common references. Until confirmed, we go with 'tight' plus the appropriate thread locker. Take the numbers below as a starting point, not gospel — you're responsible for your own build decisions.
Research / reference values (unverified against primary sources):
- AR Compensator (Flash hider): 15-20 ft-lbs torque, or no-torque timing value depending on source
- AR Handguard Screws: 20-30 in-lbs
- AR Gas Block Set Screws: 25-30 in-lbs
- AR Barrel Nut: 30 ft-lbs (per Army TM, no upper bound found)
- AR Carrier Key Screws: 50-58 in-lbs
- AR Grip Screw: 15-20 in-lbs
- Lower Receiver Extension — Rifle: 35-39 ft-lbs; Carbine: 38-42 ft-lbs
M-LOK Accessories (research):
- Metal to metal hand guards: 35 in-lbs
- Polymer or metal to polymer hand guards: 15 in-lbs
KeyMod Accessories (research):
- Polymer to metal: 15 in-lbs
- Polymer to polymer: 15 in-lbs
- Metal to metal: 30 in-lbs
Picatinny Accessories (research):
- Polymer to metal: 15 in-lbs
- Polymer to polymer: 15 in-lbs
- Metal to metal: 35-60 in-lbs
Sources: Army TM 9-1005-319-23&P (Nov 2008); community reference videos and manufacturer documentation.
All information posted here is for informational use only. If you make any modifications to your firearms based on this content, you do so at your own risk. Done incorrectly, this can render a weapon unsafe or unusable.
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