One 9/16×24″, .578×28″, 1/2×28″, 5/8×24″ or 13.5×1 LH Octogonal Thread Protector. These thread protectors have a 1.375-24 TPI and will work with solvent traps with a 1.375-24 Thead Pitch. Our thread protectors are contructed from high-grade 7075 Aircraft Aluminum reduce wear-and-tear on threads. Flat Matte Black Type III Hard-Coat Anodization.
The thread pitch size is written out on the back side of the item.
Thread Size 9/16×24″: .40 S&W pistols
Thread Size .578×28″: .45ACP pistols.
If you have a European .45ACP, you may have a 16×1 LH thread pitch. An adapter may be needed to convert to an American thread pitch.