Sig Sauer Hexium, 5.56 NATO, 5.9″ Length, 1.75″ Diameter, Cerakote Finish, Black

The Sig HEXIUM 556 INC is the Inconel version of Sig’s hexagonal-baffle 5.56 suppressor — NGSW-grade construction applied to the precision HEXIUM geometry. While the HEXIUM 556 TI (titanium) is optimized for weight savings, the INC variant uses Inconel, the same material Sig specified for the military NGSW suppressor program. Inconel handles sustained cyclic fire, higher operating temperatures, and corrosive propellant chemistry better than titanium. For shooters who run high round counts, conduct extended range sessions, or anticipate sustained semi-automatic fire with suppressed 5.56 NATO, the INC variant is the correct material choice. The hexagonal baffle geometry delivers more sound reduction per unit length than conventional round-section designs, regardless of material.

Sig HEXIUM 556 Inconel Specifications

Sig HEXIUM Suppressor Technology

The HEXIUM line is Sig’s precision suppressor family, named for the hexagonal internal baffle geometry that maximizes gas expansion volume per unit length. Rather than the traditional circular cross-section, HEXIUM baffles use a hexagonal outer form that packs more surface area and gas-capture volume into the same outer diameter as a conventional suppressor. The practical result: at a given length and diameter, HEXIUM suppressors achieve better sound reduction than equivalent round-section designs. Sig pairs HEXIUM geometry with either titanium (maximum weight savings) or Inconel (maximum heat and pressure resistance) depending on the caliber’s demands — 5.56 gets both options because it’s used in both high-rate-of-fire and precision contexts where the material tradeoff is genuinely a user choice.

Why Buy From Western Sport?

Western Sport is a licensed FFL/SOT dealer in Roanoke, Texas, specializing in NFA firearms and suppressors since 2007. We stock Sig Sauer’s full suppressor lineup and guide every buyer through the Form 4 process start to finish. Call 817-393-4000 — our team can match you with the right Sig suppressor for your application.

FAQ — Sig HEXIUM 556 INC

HEXIUM 556 INC vs. HEXIUM 556 TI — when does Inconel matter?

Inconel handles higher sustained temperatures and resists the corrosive chemistry of hot propellant gases better than titanium. In practical terms: if your 5.56 use is primarily hunting, range days with moderate round counts, or precision shooting, the titanium (TI) version saves weight with no meaningful performance trade-off. If you run high-volume semi-automatic fire — training, competitions, or sustained sessions with 500+ suppressed rounds — Inconel’s thermal and chemical resistance pays dividends in durability. The INC version is the professional/hard-use choice.

What thread pitch does the HEXIUM 556 use?

1/2×28, the standard for 5.56/.223 barrels. Compatible with any 5.56 barrel with 1/2×28 muzzle threading.

Recent eForm 4 approvals have been coming back in about two weeks or less — see our NFA wait times guide for current figures.