Aisi 429 Stainless Steel Nuts Specification

Aisi 429 Stainless Steel Equivalent Designation
| UNS Designation | British STD | Werkstoff No. | European STD | Swedish STD | Japanese STD |
|---|---|---|---|---|---|
| S42900 | – | 0.0000 | X10crni15 | 0 | Sus 429 |
AISI 429 Stainless Steel nuts are internally threaded fasteners that mate with bolts and studs to form clamped joints. TorqBolt manufactures AISI 429 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".
For vibration-loaded joints, AISI 429 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.
AISI 429 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.
TorqBolt also produces AISI 429 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.
Martensitic stainless steels are body-centered tetragonal Fe-Cr alloys (typically 12-17% Cr, >0.1% C) that respond to quench + temper heat treatment, achieving high hardness and tensile strength while retaining moderate corrosion resistance. They are magnetic and used where mechanical strength is critical and corrosion exposure is mild.
AISI 410 (UNS S41000) is the general-purpose grade for valve trim, pump shafts, turbine blades, and high-strength bolting; quench from 950-1010°C + temper at 200-700°C dial in tensile strength from 600 to 1200 MPa. AISI 416 is the free-machining variant (S+P additions). AISI 420 raises C for higher hardness (cutlery, surgical instruments). AISI 431 adds Ni for marine + aerospace fasteners. AISI 440A/B/C are the highest-hardness grades (HRC 56-60) for bearings and ball valves.
Martensitic fasteners are supplied per ASTM A276 / A479 with hardness, tensile, and impact testing per the heat-treat condition. EN 10204 3.1 / 3.2 certs standard. NACE MR0175 service is restricted — martensitic grades are SSC-susceptible above HRC 22 hardness, requiring careful temper-control for sour applications.