M4 Shoulderless Thread Adapter

(2 reviews)
Current Stock:
Adding to cart… The item has been added


Simple shoulder-less design allows thread adapter to remain fully concealed under muzzle device for a continuous, streamline look. Muzzle device seats directly against barrel shoulder maintaining full thread joint strength and providing more accurate alignment to bore. Internal and external threads are single point cut in same operation to tight UNEF Class-3 tolerances for perfect concentricity and alignment. The M4 muzzle thread adapter is precision CNC machined from pre-hardened HTSR 400-series stainless steel bar for superior heat and corrosion resistance. Allows the attachment of 5/8-24 muzzle devices to a 1/2-28, 1/2-32, or 1/2-36 threaded barrel.

NOTE: This thread adapter is intended for more permanent installation of muzzle devices. For applications where the adapter will be used on multiple devices/rifles please see our standard M4 Muzzle Thread Adapter which features wrench flats for easy installation and removal.

Available Threads:

  • 1/2-28 to 5/8-24
  • 1/2-32 to 5/8-24
  • 1/2-36 to 5/8-24


External Thread: 5/8x24"
Internal Threads: 1/2x28
Length: 0.625"
OD: 0.625"
Weight: 0.2 oz
Full Spec Sheet: View PDF


For full specifications, installation manuals, and more - visit our Technical Resources page:


  • 5
    Thread Adapter

    Posted by Randy on 26th Oct 2023

    Very nice machine work. Works just as I hoped.

  • 5
    Product Review

    Posted by Taylor Black on 5th Nov 2020

    Fits perfect. Super fast shipping! Shipped within 30 min of ordering.