Duplex Washers Manufacturer, Supplier & Stockist
Unifit Fastener is a top producer and distributor of high-quality duplex washers and duplex steel washers and serves both local and international customers. We have a wide range of washers consisting of Duplex S31803/S32205 washers, which are produced to suit various industries. Such washers come in different sizes, grades and dimensions, which makes them compatible with any application.
Our S31803 and S32205 washers are produced from high-quality raw material, which has high corrosion resistance, excellent mechanical strength, and also sturdiness. UNS S32205 and S31803 are particularly the most appropriate materials used in high-pressure conditions and high-temperature conditions, which guarantee long-term stability. The UNS S31803 equivalent can also be referred to by clients to align with the international standards to facilitate easy integration.
At Unifit Fastener, every duplex steel washer is manufactured according to the strict quality control measures. The professionals choose the most appropriate raw materials and use the most sophisticated production methods to provide accuracy, uniformity, and high performance. All washers are highly tested to comply with the best industry standards involving destructive and non-destructive testing.
To ensure safe delivery, all the Duplex Washers are packed in materials that are corrosion-free and protective so that they arrive to the clients in their original conditions. Unifit Fastener is dedicated to timely delivery without any damage, and they provide fastening solutions that are reliable in terms of durability, flexibility, and long service life. Select Unifit Fastener for high-quality Duplex S31803 and S32205 washers that provide unsurpassed quality and performance.
Request QuoteTable of Contents
- What Are Duplex Steel Washers?
- Types of Duplex Steel Washers
- Specification of Duplex Steel Washers
- Send Your Enquiry
- Equivalent Grade of Duplex Steel Washers
- Duplex Steel Washers Dimension Chart
- Duplex Steel Spring Washers Dimensions
- Duplex Steel Flat Washer Dimensions
- International Standard for Duplex Steel Washer
- Applications of Duplex Steel Washers
- People Ask About Duplex Steel Washer Manufacturer
What Are Duplex Steel Washers?
Duplex steel washers are high-strength, corrosion-resistant fasteners manufactured as an alloy of stainless steel, both austenitic and ferritic in nature, which perform better in extreme conditions such as in the marine, chemical and oil and gas industries. They show great resistance to pitting, crevice corrosion and stress cracking and have high mechanical strength and durability, and so they are good at securing bolts as well as cushioning in stressful applications. The most important ones are plain, spring, lock, and tab washers, offered in such grades as Duplex 2205 (UNS S31803/S32205) and Super Duplex 2507 (UNS S32750/S32760).
Types of Duplex Steel Washers
Duplex Square Washer
Duplex Spring Washer
Duplex Split Washer
Duplex Plain Washer
Duplex Ogee Washer
Duplex Flat Washer
Specification of Duplex Steel Washers
| Parameter | Details |
|---|---|
| Trade Name | Duplex S31803 / S32205 / 2205 Washer |
| Standard | ASTM A479 / ASME SA479 |
| Dimensions | ASTM, DIN, BS, GB, IS & all International Standards |
| Size Range | M3 – M56 | 3/6″ to 2″ | Custom Sizes Available |
| Thickness / Length | 3 mm to 200 mm |
| Marking | Grade, Standard, Thickness, Heat No. (or as per customer requirement) |
| Delivery Time | 7–15 working days (depends on order quantity) |
| Payment Terms | PayPal, Western Union, T/T (Wire Transfer), L/C, Trade Assurance – 30% advance & balance before shipment |
| Free Sample | Available (subject to stock) |
Send Your Enquiry
Equivalent Grade of Duplex Steel Washers
| Standard | Werkstoff Nr. | UNS |
|---|---|---|
| Duplex 2205 | 1.4462 | S31803 / S32205 |
Duplex Steel Washers Dimension Chart
| Size | USS Inside Diameter (A) | USS Outside Diameter (B) | USS Thickness (C) | SAE Inside Diameter (A) | SAE Outside Diameter (B) | SAE Thickness (C) |
|---|---|---|---|---|---|---|
| #2 | – | – | – | 3/32" | 1/4" | 0.020" |
| #4 | – | – | – | 1/8" | 5/16" | 0.032" |
| #6 | – | – | – | 5/32" | 3/8" | 0.049" |
| #8 | – | – | – | 3/16" | 7/16" | 0.049" |
| #10 | – | – | – | 7/32" | 1/2" | 0.049" |
| #12 | – | – | – | 1/4" | 9/16" | 0.065" |
| 1" | 1-1/16" | 2-1/2" | 0.165" | 1-1/16" | 2" | 0.134" |
| 1/2" | 9/16" | 1-3/8" | 0.109" | 17/32" | 1-1/16" | 0.095" |
| 1/4" | 5/16" | 0.734" | 0.065" | 9/32" | 5/8" | 0.065" |
| 1-1/2" | 1-5/8" | 3-1/2" | 0.180" | – | – | – |
| 1-1/4" | 1-3/8" | 3" | 0.165" | – | – | – |
| 1-1/8" | 1-1/4" | 2-3/4" | 0.165" | – | – | – |
| 1-3/4" | 1-7/8" | 4" | 0.180" | – | – | – |
| 1-3/8" | 1-1/2" | 3-1/4" | 0.180" | – | – | – |
| 1-5/8" | 1-3/4" | 3-3/4" | 0.180" | – | – | – |
| 2" | 2-1/8" | 4-1/2" | 0.213" | – | – | – |
| 3/4" | 13/16" | 2" | 0.148" | 13/16" | 1-15/32" | 0.134" |
| 3/8" | 7/16" | 1" | 0.083" | 13/32" | 13/16" | 0.065" |
| 5/8" | 11/16" | 1-3/4" | 0.134" | 21/32" | 1-5/16" | 0.095" |
| 5/16" | 3/8" | 7/8" | 0.083" | 11/32" | 11/16" | 0.065" |
| 7/8" | 15/16" | 2-1/4" | 0.165" | 15/16" | 1-3/4" | 0.134" |
| 7/16" | 1/2" | 1-1/4" | 0.083" | 15/32" | 15/16" | 0.065" |
| 9/16" | 5/8" | 1-15/32" | 0.109" | 19/32" | 1-5/32" | 0.095" |
Duplex Steel Spring Washers Dimensions
| NOM SIZE | Inner Dia (d) Basic Tol (+) | Outer Dia (d1) Max | WIDTH (b) Basic Tol (+ or -) | THICKNESS (S) Basic Tol (+ or -) | Weight per 1000 in Kgs |
|---|---|---|---|---|---|
| 3 | 3.1 | 6.2 | 1.3 | 0.8 | 0.11 |
| 4 | 4.1 | 7.6 | 1.5 | 0.9 | 0.18 |
| 5 | 5.1 | 9.2 | 1.8 | 1.2 | 0.36 |
| 6 | 6.1 | 11.8 | 2.5 | 1.6 | 0.83 |
| 8 | 8.1 | 14.8 | 3 | 2 | 1.60 |
| 10 | 10.2 | 18.1 | 3.5 | 2.2 | 2.53 |
| 12 | 12.2 | 21.1 | 4 | 2.5 | 3.82 |
| 14 | 14.2 | 24.1 | 4.5 | 3 | 6.01 |
| 16 | 16.2 | 27.4 | 5 | 3.5 | 8.91 |
| 18 | 18.2 | 29.4 | 5 | 3.5 | 9.73 |
| 20 | 20.2 | 33.6 | 6 | 4 | 15.20 |
| 22 | 22.5 | 35.9 | 6 | 4 | 16.50 |
| 24 | 24.5 | 40 | 7 | 5 | 26.20 |
| 27 | 27.5 | 43 | 7 | 5 | 28.70 |
| 30 | 30.5 | 48.2 | 8 | 6 | 44.30 |
| 33 | 33.5 | 55.2 | 10 | 6 | 63.00 |
| 36 | 36.5 | 58.2 | 10 | 6 | 67.30 |
| 39 | 39.5 | 61.2 | 10 | 6 | 71.70 |
| 42 | 42.5 | 68.2 | 12 | 7 | 111.00 |
| 45 | 45.5 | 71.2 | 12 | 7 | 117.00 |
| 48 | 49 | 75 | 12 | 7 | 123.00 |
| 52 | 53 | 83 | 14 | 8 | 320.00 |
Duplex Steel Flat Washer Dimensions
| Bolt Size | USS OD (in.) | USS ID (in.) | USS Thickness | SAE OD (in.) | SAE ID (in.) | SAE Thickness |
|---|---|---|---|---|---|---|
| 1 | 2.500 | 1.062 | .136/.192 | 2.000 | 1.062 | .108/.160 |
| 1/2 | 1.375 | 0.562 | .086/.132 | 1.062 | 0.531 | .074/.121 |
| 1/4 (#14) | 0.734 | 0.312 | .051/.080 | 0.625 | 0.281 | .051/.080 |
| 1/8 (#6) | – | – | – | 0.375 | 0.156 | .036/.065 |
| 2 | 4.500 | 2.125 | .153/.213 | – | – | – |
| 3 | 5.500 | 3.125 | .249/.327 | – | – | – |
| 3/4 | 2.000 | 0.812 | .122/.177 | 1.469 | 0.812 | .108/.160 |
| 3/8 | 1.000 | 0.438 | .064/.104 | 0.812 | 0.406 | .051/.080 |
| 3/16 (#10) | 0.560 | 0.250 | .036/.065 | 0.500 | 0.220 | .036/.065 |
| 5/8 | 1.750 | 0.688 | .108/.160 | 1.312 | 0.656 | .074/.121 |
| 5/16 | 0.875 | 0.375 | .064/.104 | 0.688 | 0.344 | .051/.080 |
| 5/32 (#8) | – | – | – | 0.438 | 0.188 | .036/.065 |
| 7/8 | 2.250 | 0.938 | .136/.192 | 1.750 | 0.938 | .108/.160 |
| 7/16 | 1.250 | 0.500 | .064/.104 | 0.922 | 0.469 | .051/.080 |
| 7/32 (#12) | – | – | – | 0.562 | 0.250 | .051/.080 |
| 9/16 | 1.469 | 0.625 | .086/.132 | 1.156 | 0.594 | .074/.121 |
| 1 1/2 | 3.500 | 1.625 | .153/.213 | 3.000 | 1.625 | .153/.213 |
| 1 1/4 | 3.000 | 1.375 | .136/.192 | 2.500 | 1.375 | .136/.192 |
| 1 1/8 | 2.750 | 1.250 | .136/.192 | 2.250 | 1.250 | .108/.160 |
| 1 3/4 | 4.000 | 1.875 | .153/.213 | – | – | – |
| 1 3/8 | 3.250 | 1.500 | .153/.213 | 2.750 | 1.500 | .136/.213 |
| 1 5/8 | 3.750 | 1.750 | .153/.213 | – | – | – |
| 1 7/8 | 4.250 | 2.000 | .153/.213 | – | – | – |
| 2 1/2 | 5.000 | 2.625 | .210/.280 | – | – | – |
| 2 1/4 | 4.750 | 2.375 | .320/.248 | – | – | – |
| 2 3/4 | 5.250 | 2.875 | .228/.410 | – | – | – |
International Standard for Duplex Steel Washer
| Standard | Description |
|---|---|
| AS 1237.1-2002 | Plain washers |
| AS 1237.1-2002 | Small plain washers |
| ASTM F436-2010 | Extra Thick clipped washers |
| ASTM F436M-2010 | Clipped washers |
| ANSI B18.2.6-2003 | Steel Circular clipped washers |
| ANSI B18.22.1A-1981 | Type A Plain washers |
| ANSI B18.22.1B-1981 | Type B Plain washers |
| ANSI B18.22.1A-1965 | Type A Plain washers |
| ANSI B18.22.1B-1965 | Type B Plain washers |
| DIN 125-2 | Type A washers |
| DIN 125-2 | Type B washers |
Applications of Duplex Steel Washers
Unifit Fastener’s Duplex Washers are widely used across industries due to their superior corrosion resistance and mechanical strength:
- Oil & Gas: Offshore rigs, pipelines, valves, and pumps
- Chemical & Petrochemical: Reactors, heat exchangers, and pressure vessels
- Marine Industry: Shipbuilding, seawater handling systems, and desalination plants
- Power Plants: Boilers, turbines, and condensers
- Heavy Engineering: Machinery, structural assemblies, and high-pressure equipment
People Ask About Duplex Steel Washer Manufacturer
What is a Duplex Steel Washer?
A Duplex Steel Washer is a washer manufactured from duplex stainless steel grades such as UNS S31803 or UNS S32205. These washers offer an excellent combination of high mechanical strength and superior corrosion resistance, making them suitable for demanding industrial applications.
What are the differences between S31803 and S32205?
S31803 duplex stainless steel provides good corrosion resistance and high toughness, making it suitable for general industrial environments. S32205 offers enhanced corrosion resistance, particularly against pitting and crevice corrosion in chloride-rich and harsh environments, along with higher strength.
What is UNS S31803 and UNS S32205?
UNS S31803 and UNS S32205 are Unified Numbering System (UNS) designations for duplex stainless steel grades. UNS S31803 corresponds to the standard S31803 material, while UNS S32205 represents an improved duplex grade with higher chromium, molybdenum, and nitrogen content for better corrosion resistance.
Where are Duplex Washers commonly used?
Duplex Steel Washers are widely used in high-pressure, high-temperature, and corrosive environments. Common applications include oil and gas industries, chemical processing plants, marine and offshore structures, power generation facilities, and heat exchangers.
How long do Duplex Steel Washers last?
Duplex Steel Washers offer a long service life when properly installed and maintained. Their excellent resistance to corrosion, stress corrosion cracking, and high mechanical strength ensures reliable performance even in aggressive operating conditions.