AISI 416C Stainless Steel Flange Rings manufactured at TorqBolt are corrosion resistant,low maintainence,silver finish.
Dimensional standards as per DIN 471,DIN 472,DIN 5417,DIN 983,AS 568,BS 1806,ISO 3601,DIN 3771 are provided.
The raw material of these fasteners is classified as Martensitic Stainless Steel. Being a PED certified Fasteners Manufacturer by TUV Rheinland,our fasteners are accompanied with EN 10204 3.1/3.2 certification. AISI 416C Stainless Steel Flange Rings are available in hot forged,cold forged and bar stock machined conditions depending upon the order quantity.
AISI 416c Stainless Steel Flange Rings — Forged Ring Specifications
AISI 416c Stainless Steel Flange rings are seamless rolled or open-die forged components used as pressure-vessel flanges, valve bodies, hub-mount blanks, and shaft-end retention rings. TorqBolt supplies AISI 416c Stainless Steel Flange rings per ASTM A182 (forged flange standard), ASTM A266/A668 (carbon ring), and EN 10222 (pressure-purpose forging), in OD sizes from 50 mm up to 3000 mm.
Forging Process
Rings are produced via either seamless ring rolling (radial-axial mill, for OD > 200 mm) or open-die hammer forging (for short-run / oversize parts). Reduction ratio ≥ 4:1 from billet to final ring is enforced for grain-flow continuity. Heat treatment is per the alloy spec — solution-anneal + quench + age for precipitation-hardening alloys; quench & temper for low-alloy steels.
Dimensional Tolerance
AISI 416c Stainless Steel Flange rings are supplied to ASTM A788 dimensional tolerances by default: OD ±1.5 mm or ±1% (whichever is larger), ID ±1.5 mm, height ±0.8 mm. Tighter tolerances (machined finish, ±0.1 mm) available for direct-mount applications. Out-of-roundness controlled to 1.5 mm; concentricity 0.2 mm/100 mm.
Mechanical Testing
Each ring lot ships with full mechanical certification: tensile (ASTM E8), Charpy impact (ASTM E23) at the application's MDMT, hardness traverse, and grain size per ASTM E112. For AISI 416c Stainless Steel Flange ring stock destined for hydrogen / sour service, additional HIC testing (NACE TM0284) and SSC testing (NACE TM0177) per the customer's spec.
Surface & Inspection
AISI 416c Stainless Steel Flange rings ship rough-machined or finish-machined per drawing. Standard NDT: 100 % UT (ASTM A388 reference) and surface MT/PT to ASTM E709 / E165. Radiography on request. Each ring is hard-stamped with heat number, lot, and certification reference for traceability through the dispatch chain.
Martensitic Stainless Steel (400-series)
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.
