Aisi 303 Stainless Steel Nuts manufactured at TorqBolt are corrosion resistant,low maintainence,silver finish.
Dimensional standards as per ANSI B18.2.2 in imperial and ANSI B18.2.4.6M in metric are provided.
The raw material of these fasteners is classified as Austenitic Stainless Steel. Being a PED certified Fasteners Manufacturer by TUV Rheinland,our fasteners are accompanied with EN 10204 3.1/3.2 certification. Aisi 303 Stainless Steel Nuts are available in hot forged,cold forged and bar stock machined conditions depending upon the order quantity.
AISI 303 is most easily machinable Steel of all austenitic grades of stainless steel. This property is due to presence of sulphur in the steel composition, as the sulphur content improves machining, decreases corrosion resistance although it remains good in mild environment and reduces the toughness. It is not advisable to use it in marine environments. It has good oxidation resistance when it is exposed to higher temperatures as 760 Degrees celcious. however, it starts to show carbide precipitation at prolonged exposure to higher temperatures. It is easily cold worked, however sharp bending is not advisable.
AISI 303 Stainless Steel nuts are internally threaded fasteners that mate with bolts and studs to form clamped joints. TorqBolt manufactures AISI 303 Stainless Steel 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, AISI 303 Stainless Steel 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
AISI 303 Stainless Steel 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 AISI 303 Stainless Steel 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.
Austenitic Stainless Steel (300-series)
Austenitic stainless steels form the workhorse 300-series — face-centered cubic Fe-Cr-Ni alloys delivering excellent corrosion resistance, formability, weldability, and toughness from cryogenic to ~600°C. They are non-magnetic in the annealed condition and the default choice for food, dairy, pharmaceutical, marine, and general process-industry fasteners.
AISI 304 (18Cr-8Ni, UNS S30400) is the baseline; 304L (low-C) prevents weld sensitization for thicker sections. AISI 316 adds 2-3% Mo for chloride pitting resistance, and 316L is the welding-grade marine standard. 309 / 310 are the high-Cr grades for elevated temperatures (to ~1100°C). 321 / 347 are Ti / Nb-stabilized for stress-relieved welded service. 304LN / 316LN add nitrogen for higher yield without sacrificing corrosion.
Austenitic fasteners are supplied per ASTM A193 grade B8 (304), B8M (316), B8T (321), B8C (347) and ASTM A276 / A479 for general bar. EN 10204 3.1 / 3.2 certs cover mechanicals, hardness (HB ~150-217), intergranular-corrosion testing (ASTM A262 Practice E), and surface condition. NACE MR0175 sour-service compliance maintained below the hardness threshold for SSC.
