Tube .875 x 18 x 5/8 thread

The U-B Machine Tube .875 x 18 x 5/8 Thread (MPN 42-1803-C) is a precision-engineered suspension component designed for suppressors, sound moderators, and similar tactical accessories requiring a robust threaded tube interface. This 18-inch steel tube with 5/8-18 female thread and .875-inch outer diameter serves as a core structural element in suppressor assembly, providing the mounting and retention interface between muzzle-mounted devices and host firearms. The black powder coat finish delivers corrosion resistance suitable for field environments and extended outdoor duty.

Built from steel and finished with a durable powder coat, this tube withstands the thermal cycling and pressure cycles inherent to suppressor operation. The 5/8-18 female thread specification is a standard interface in suppressor engineering, allowing compatibility with common muzzle devices and brake platforms. At 18 inches in length and 1.23 pounds, the tube maintains dimensional stability while remaining manageable for assembly and service. The .875-inch OD provides adequate wall thickness for sound attenuation chamber construction without excessive weight. Precision machining ensures concentricity and thread tolerance critical for alignment of internal baffles and suppressor cones.

This component is specified for custom suppressor builds, sound moderator assembly, and platform-specific silencer manufacturing. Gunsmiths, suppressor manufacturers, and armorer-level technicians rely on precision tube stock to maintain the exacting tolerances required for effective sound reduction and reliable firearm function. The 5/8-18 thread pitch is widely used across rifle and pistol platform suppressors, making this tube a versatile base element for multi-platform builds. Whether restocking existing assemblies or engineering new configurations, the verified dimensions and steel construction ensure repeatable performance across production runs.