What material grade does Duplex 31803 Spring Washers use?

Duplex 31803 Spring Washers are manufactured per the applicable ASTM, ASME, DIN, or ISO specification for the material grade. TorqBolt provides material test certificates (MTC) per EN 10204 3.1 or 3.2 with every supply.

What sizes are available for Duplex 31803 Spring Washers?

TorqBolt manufactures Duplex 31803 Spring Washers in metric sizes M6 to M100 and imperial sizes 1/4" to 4" diameter, with custom lengths from 10mm to 3000mm. Non-standard sizes are available on request.

Are Duplex 31803 Spring Washers NACE MR0175 / ISO 15156 certified?

Yes, Duplex 31803 Spring Washers can be supplied with NACE MR0175 / ISO 15156-2/3 sour service certification when specified at order. Material certificates and test reports are provided.

What is the typical delivery time for Duplex 31803 Spring Washers?

Standard stock items ship in 1-2 weeks. Custom manufactured Duplex 31803 Spring Washers typically ship in 4-6 weeks depending on quantity, material availability, and certification requirements.

Do you provide third-party inspection for Duplex 31803 Spring Washers?

Yes, third-party inspection by TUV, Lloyd's Register, BV, DNV, SGS, and Intertek is available upon request for Duplex 31803 Spring Washers. Witness testing and stage inspections can be arranged.

Duplex 31803 Spring Washers Supplier

Duplex 31803 Spring Washers Specification

The raw material of these fasteners is classified as Duplex Stainless Steel. Being a PED certified Fasteners Manufacturer by TUV Rheinland,our fasteners are accompanied with EN 10204 3.1/3.2 certification. Duplex 31803 Spring Washers are available in hot forged,cold forged and bar stock machined conditions depending upon the order quantity.

Duplex 31803 Spring Washers Equivalent Designation

UNS Designation	British STD	Werkstoff No.	European STD	Swedish STD	Japanese STD	Forging
S31803	318S13	1.4470	X2CrNiMoN22-5-3	2377	SUS 329J3L	Sa 182 F51

Surface Treatments & Coatings

Electro Less Nickel Plating Washers Electro Cadmium Plating Washers Dacromet 320 500 Coating Washers Pickled Passivated Fasteners Washers Silver Plating Washers Nickel Plating Washers Electro Zinc Cobalt Plating Washers Electro Zinc Nickel Plating Washers Ptfe Fluorocarbon Coating Washers Aluminizing Washers Ceramic Filled Fluorocarbon Coating Washers

Related Products

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Duplex 31803 Spring Washers — Specifications & Dimensions

Duplex 31803 Spring washers distribute clamp load over a wider bearing area, prevent surface damage, and accommodate bolt-hole oversize. TorqBolt manufactures Duplex 31803 Spring washers per ASME B18.21.1 / B18.22.1, DIN 125 / 126 / 127 / 9021, and ISO 7089 / 7090 / 7093 / 7094, in metric (M3–M100) and imperial (#4–4") sizes.

Plain Washer Dimensions

Duplex 31803 Spring plain washers are characterized by three critical dimensions: ID (clearance over bolt diameter), OD (load distribution area), and thickness (compressive stiffness). Standard tolerances are h13 on OD and H13 on ID per ISO 286-2; flatness 0.05 mm/100 mm and parallelism 0.05 mm/100 mm verified per lot. Edge break / chamfer per drawing.

Form Variants

Form A (regular) — DIN 125-A / ISO 7089, the default plain washer

Form B (large OD) — DIN 9021 / ISO 7093, for soft mating surfaces

Form C (heavy) — DIN 7349 / ISO 7094, for slotted holes / structural use

Spring (split) — DIN 127 / ASME B18.21.1, helical anti-vibration

Tooth lock (internal / external) — DIN 6797 / 6798, anti-rotation

Conical / Belleville (DIN 6796 / 2093) — preload maintenance

Hardness & Surface

Duplex 31803 Spring washers are hardness-controlled to balance load-distribution stiffness against surface damage to mating parts. Typical Vickers HV ranges: plain 140–180 HV; spring 380–440 HV; Belleville 460–540 HV. Surface finish Ra 1.6 µm or better; on critical sealing applications, Ra 0.8 µm available.

Special Patterns

TorqBolt produces Duplex 31803 Spring washers in square (DIN 436), fender (oversized OD), tab / lock-tang (DIN 462 / 463), and spherical seat washer + cup combinations. EN 10204 3.1 / 3.2 material certificates standard; NACE MR0175 / ISO 15156 on request.

Duplex & Super Duplex Stainless Steels

Duplex stainless steels have a roughly 50/50 ferrite-austenite microstructure, doubling the yield strength of austenitic 304/316 grades while improving chloride pitting + stress-corrosion resistance. Duplex is the modern default for offshore platform fasteners, desalination plants, and sour-gas piping where austenitics fail to chloride SCC and martensitics fail to hydrogen embrittlement.

Duplex 2205 (UNS S32205 / S31803) is the standard grade with PREN ~35, suitable for chloride-bearing service to ~250°C. Super Duplex 2507 (S32750) and Zeron 100 (S32760) push PREN to 41-42 with higher Cr+Mo+N, qualifying for the most aggressive seawater + sour-well environments. SA-182 F51 / F53 / F55 / F60 are the ASME forged-flange equivalents.

Phase balance is critical: ferrite content must stay within 35-65% in weld + HAZ to maintain corrosion + impact properties (ASTM A923 testing). Solution anneal at 1040-1100°C followed by water quench locks the duplex microstructure. Fasteners ship per ASTM A276 / A479 with EN 10204 3.1 / 3.2 certs including ferrite count and Charpy impact at -46°C. NACE MR0175 / ISO 15156 sour-service certification is standard.

Duplex 31803 Spring Washers