Cupronickel 70-30 Nylon Lock Nuts manufactured at TorqBolt are seawater resistant,crevice resistant,stress corrosion crack resistant & hydrogen embrittlement resistant.
Dimensional standards as per DIN 985,ISO 10511,DIN 982,DIN 6924,DIN 7040,DIN 10541 are provided.
The raw material of these fasteners is classified as copper based nickels. Being a PED certified Fasteners Manufacturer by TUV Rheinland,our fasteners are accompanied with EN 10204 3.1/3.2 certification. Cupronickel 70-30 Nylon Lock Nuts are available in hot forged,cold forged and bar stock machined conditions depending upon the order quantity.
Cupronickel 70 30 Nylon Lock nuts are internally threaded fasteners that mate with bolts and studs to form clamped joints. TorqBolt manufactures Cupronickel 70 30 Nylon Lock 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, Cupronickel 70 30 Nylon Lock 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
Cupronickel 70 30 Nylon Lock 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 Cupronickel 70 30 Nylon Lock 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.
Copper-Nickel & Cupronickel Alloys
Copper-nickel (cupronickel) alloys combine copper's bio-fouling resistance with nickel's strength and corrosion enhancement. The two production grades dominate marine + desalination service where titanium is too costly: 90/10 Cu-Ni (~90% Cu, 10% Ni) and 70/30 Cu-Ni. Cu-Ni alloys are the only commercial materials inherently resistant to marine bio-fouling, eliminating the need for antifouling coatings on heat-exchanger tubes and ship hulls.
C70600 (90/10 Cu-Ni) is the high-volume marine alloy: yield ~105 MPa, used for desalination tubing, condenser tubes, hull cladding, and offshore piping fasteners. C71500 (70/30 Cu-Ni) increases nickel for higher strength (~160 MPa yield) and better seawater erosion-corrosion at higher flow velocities — the choice for naval condensers and high-pressure desalination. C71640 (70/30 + Fe + Mn) extends service to even higher flow rates.
Cu-Ni fasteners ship per ASTM B151 (rod/bar) and B171 (plate/forging) with EN 10204 3.1 / 3.2 certificates. Welding uses ERCuNi or ENiCu-7 filler with low-heat-input technique to avoid hot cracking. NACE MR0175 sour-service application is limited; ammoniacal stress-corrosion can occur if exposed to NH₃ in service.
