NITRONIC 50 Coupling Nuts manufactured at TorqBolt are corrosion resistant,high temperature resistant with ultimate tensile strength.
Dimensional standards as per DIN 439B,DIN 6334,ISO 898-2,DIN 3871,DIN 8434-119 are provided.
The raw material of these fasteners is further classified as ALLOY XM-19. Being a PED certified Fasteners Manufacturer by TUV Rheinland,our fasteners are accompanied with EN 10204 3.1/3.2 certification. NITRONIC 50 Coupling Nuts are available in hot forged,cold forged and bar stock machined conditions depending upon the order quantity.
Nitronic 50 Coupling nuts are internally threaded fasteners that mate with bolts and studs to form clamped joints. TorqBolt manufactures Nitronic 50 Coupling nuts per ASME B18.2.2, ISO 4032/4033/4034, DIN 934/EN 24032, and DIN 6915 (heavy hex), in sizes M6–M100 and 1/4"–4".
Nut Height Categories
Standard / regular hex nut — ~0.875×D height, ASME B18.2.2 Type 1
Heavy hex nut — ~D height, full strength matched to bolt grade (A194 2H pattern)
Jam / thin nut — 0.5×D height, used as locknut against a primary nut
Coupling nut — long-form for joining two threaded rods
Cap / acorn nut — closed-end, decorative + thread protection
Locking Variants
For vibration-loaded joints, Nitronic 50 Coupling nuts are available as nyloc (polymer insert), all-metal prevailing-torque (DIN 980, distorted-thread style), flange-serrated (DIN 6923, integral washer face with anti-back-off teeth), and castle / slotted (DIN 935, cotter-pin retention). Each locking style trades reusability against prevailing-torque retention.
Thread & Mechanical
Nitronic 50 Coupling nut threads are gauged per ASME B1.1 / ISO 965 to Class 2B / 6H by default; high-strength variants use 3B / 4H6H. Proof-load testing per ASTM F606 verifies the nut can develop the bolt's full strength without thread strip; hardness range is controlled to prevent stress-corrosion susceptibility (HV 250–353 typical for high-grade nuts). Each lot is EN 10204 3.1 / 3.2 certified.
Special Patterns
TorqBolt also produces Nitronic 50 Coupling nuts in weld-nut, T-nut, square-nut, knurled thumb-nut, and rivet-nut patterns. NACE MR0175 / ISO 15156 sour-service certification available; NORSOK M-650 qualified mills supplying high-temperature service grades.
Nitronic stainless steels are nitrogen-strengthened austenitic alloys that achieve high yield strength (1.5-2× conventional 304/316) without the heat-treatment required for precipitation-hardening grades. Nitrogen acts as a powerful interstitial solid-solution strengthener while remaining fully austenitic, retaining the corrosion resistance and toughness of standard austenitics.
Nitronic 50 (UNS S20910) is the dominant grade: 22Cr-13Ni-5Mn-2Mo-0.3N giving yield ~380 MPa in the annealed condition (vs ~205 MPa for 316L) and corrosion resistance better than 316L. The standard choice for high-strength corrosion-resistant fasteners in marine + chemical-process service. Nitronic 60 (S21800) trades some corrosion for outstanding galling and wear resistance — the workhorse for valve trim, threaded couplings, and wear-prone bolting where galling would destroy a 304/316 thread. Nitronic 32 / 33 / 40 are low-Ni variants for cost-sensitive applications.
Nitronic fasteners ship per ASTM A276 / A479 with EN 10204 3.1 / 3.2 certification covering nitrogen content (critical for property reproducibility), tensile, hardness, and stress-corrosion testing. NACE MR0175 sour-service is fully qualified in the annealed condition for both Nitronic 50 and 60.
