- Call Us+91 9819454781
- Email Usinquiry@kkfasteners.com
- WhatsApp+91 9819454781
Super Duplex Steel S32750 Washers are engineered for extreme mechanical load distribution and corrosion resistance in highly aggressive environments such as offshore platforms, chemical processing units, and marine engineering systems. Manufactured from UNS S32750 material, these washers combine austenitic and ferritic microstructures, delivering exceptional strength with superior resistance to pitting, crevice corrosion, and chloride-induced stress cracking.
With compliance to international standards such as ASTM A240 and relevant DIN/ISO fastener specifications, these washers are widely used in structural bolting assemblies where reliability under pressure and corrosive exposure is critical. They play a vital role in maintaining bolt preload integrity across dynamic and high-vibration systems.
KK Fasteners supplies these washers to global EPC contractors and industrial OEMs, ensuring full material traceability, precision machining, and strict dimensional control for every batch shipped across international markets.
| Parameter | Specification |
|---|---|
| Material | Super Duplex Stainless Steel UNS S32750 |
| Grade | SAF 2507 Equivalent |
| Size Range | M3 to M100 / Custom Inch Sizes |
| Standards | DIN 125, DIN 9021, ISO 7089, ASTM A240 |
| Thread Compatibility | Metric (Coarse/Fine), UNC, UNF |
| Hardness | 28–32 HRC (Approx.) |
| Tensile Strength | ≥ 800 MPa |
| Surface Finish | Bright, Passivated, Black Oxide (Custom) |
| Type Variants | Flat Washer, Spring Washer, Heavy Duty Washer |
| S32750 | C | N | P | Si | Mn | Mo | Ni | Cr | S | Other |
| 0.030 | 0.24/0.32 | 0.035 | 0.80 | 1.20 | 3.0/5.0 | 6.00/8.00 | 24.0/26.0 | 0.020 | Cu:0.50 |
| S32750 | Density | Melting Point | Yield Strength (0.2%Offset) | Tensile Strength | Elongation |
| 7.8 g/cm3 | 1350 °C (2460 °F) | Psi – 80000 , MPa – 550 | Psi – 116000 , MPa – 800 | 15 % |
| STANDARD | UNS | WERKSTOFF NR. |
| Super Duplex S32750 | S32750 | 1.4410 |
Bolt Size
|
USS
|
SAE
|
||||
OD (in.)
|
ID (in.)
|
Thickness
|
OD (in.)
|
ID (in.)
|
Thickness
|
|
1/8 (#6)
|
-
|
-
|
-
|
0.375
|
0.156
|
.036/.065
|
5/32 (#8)
|
-
|
-
|
-
|
0.438
|
0.188
|
.036/.065
|
3/16 (#10)
|
0.560
|
0.250
|
.036/.065
|
0.500
|
0.220
|
.036/.065
|
7/32 (#12)
|
-
|
-
|
-
|
0.562
|
0.250
|
.051/.080
|
1/4 (#14)
|
0.734
|
0.312
|
.051/.080
|
0.625
|
0.281
|
.051/.080
|
5/16
|
0.875
|
0.375
|
.064/.104
|
0.688
|
0.344
|
.051/.080
|
3/8
|
1.000
|
0.438
|
.064/.104
|
0.812
|
0.406
|
.051/.080
|
7/16
|
1.250
|
0.500
|
.064/.104
|
0.922
|
0.469
|
.051/.080
|
1/2
|
1.375
|
0.562
|
.086/.132
|
1.062
|
0.531
|
.074/.121
|
9/16
|
1.469
|
0.625
|
.086/.132
|
1.156
|
0.594
|
.074/.121
|
5/8
|
1.750
|
0.688
|
.108/.160
|
1.312
|
0.656
|
.074/.121
|
3/4
|
2.000
|
0.812
|
.122/.177
|
1.469
|
0.812
|
.108/.160
|
7/8
|
2.250
|
0.938
|
.136/.192
|
1.750
|
0.938
|
.108/.160
|
1
|
2.500
|
1.062
|
.136/.192
|
2.000
|
1.062
|
.108/.160
|
1 1/8
|
2.750
|
1.250
|
.136/.192
|
2.250
|
1.250
|
.108/.160
|
1 1/4
|
3.000
|
1.375
|
.136/.192
|
2.500
|
1.375
|
.136/.192
|
1 3/8
|
3.250
|
1.500
|
.153/.213
|
2.750
|
1.500
|
.136/.213
|
1 1/2
|
3.500
|
1.625
|
.153/.213
|
3.000
|
1.625
|
.153/.213
|
1 5/8
|
3.750
|
1.750
|
.153/.213
|
-
|
-
|
-
|
1 3/4
|
4.000
|
1.875
|
.153/.213
|
-
|
-
|
-
|
1 7/8
|
4.250
|
2.000
|
.153/.213
|
-
|
-
|
-
|
2
|
4.500
|
2.125
|
.153/.213
|
-
|
-
|
-
|
2 1/4
|
4.750
|
2.375
|
.320/.248
|
-
|
-
|
-
|
2 1/2
|
5.000
|
2.625
|
.210/.280
|
-
|
-
|
-
|
2 3/4
|
5.250
|
2.875
|
.228/.410S
|
-
|
-
|
-
|
3
|
5.500
|
3.125
|
.249/.327
|
-
|
-
|
-
|
Size |
USS |
SAE |
||||
|---|---|---|---|---|---|---|
Inside Diameter (A) |
Outside Diameter (B) |
Thickness (C) |
Inside Diameter (A) |
Outside Diameter (B) |
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" |
1/4" |
5/16" |
0.734" |
0.065" |
9/32" |
5/8" |
0.065" |
5/16" |
3/8" |
7/8" |
0.083" |
11/32" |
11/16" |
0.065" |
3/8" |
7/16" |
1" |
0.083" |
13/32" |
13/16" |
0.065" |
7/16" |
1/2" |
1-1/4" |
0.083" |
15/32" |
15/16" |
0.065" |
1/2" |
9/16" |
1-3/8" |
0.109" |
17/32" |
1-1/16" |
0.095" |
9/16" |
5/8" |
1-15/32" |
0.109" |
19/32" |
1-5/32" |
0.095" |
5/8" |
11/16" |
1-3/4" |
0.134" |
21/32" |
1-5/16" |
0.095" |
3/4" |
13/16" |
2" |
0.148" |
13/16" |
1-15/32" |
0.134" |
7/8" |
15/16" |
2-1/4" |
0.165" |
15/16" |
1-3/4" |
0.134" |
1" |
1-1/16" |
2-1/2" |
0.165" |
1-1/16" |
2" |
0.134" |
1-1/8" |
1-1/4" |
2-3/4" |
0.165" |
- |
- |
- |
1-1/4" |
1-3/8" |
3" |
0.165" |
- |
- |
- |
1-3/8" |
1-1/2" |
3-1/4" |
0.180" |
- |
- |
- |
1-1/2" |
1-5/8" |
3-1/2" |
0.180" |
- |
- |
- |
1-5/8" |
1-3/4" |
3-3/4" |
0.180" |
- |
- |
- |
1-3/4" |
1-7/8" |
4" |
0.180" |
- |
- |
- |
2" |
2-1/8" |
4-1/2" |
0.213" |
- |
- |
- |
Super Duplex Steel S32750 Washers are widely used wherever extreme corrosion resistance and high mechanical stability are required in bolted assemblies.
Super Duplex Steel S32750 Washers are manufactured using precision stamping and CNC-controlled machining processes to ensure exact dimensional accuracy. The production begins with certified raw material melting, followed by hot forging and controlled heat treatment to achieve the required duplex microstructure.
Each batch undergoes strict quality inspections including dimensional verification, hardness testing, and surface finish validation. Corrosion resistance is enhanced through controlled passivation processes. Traceability is maintained through heat number tracking and batch documentation.
KK Fasteners follows ISO 9001:2015 quality management systems, ensuring consistent compliance with international fastener standards and customer-specific engineering requirements for every shipment.
Explore our comprehensive range of products, ensuring you find the perfect solution for your specific requirements.
Save money without compromising on quality, thanks to our competitive prices and cost-effective options.
Personalized assistance, prompt responses, and a commitment to meeting your needs, making your purchase process seamless.
Super Duplex Steel S32750 Washers are high-strength fastening components made from UNS S32750 alloy. They are designed to distribute load evenly in bolted joints while offering excellent resistance to pitting, crevice corrosion, and chloride environments, making them suitable for offshore, marine, and chemical industries.
S32750 washers are manufactured from super duplex stainless steel, which has a dual-phase microstructure of austenite and ferrite. This composition provides high mechanical strength, excellent corrosion resistance, and superior durability compared to standard stainless steel grades.
These washers are typically produced according to international standards such as DIN 125, DIN 9021, ISO 7089, and ASTM A240. These standards ensure proper dimensional tolerances, material quality, and compatibility with global fastening systems.
They are commonly used in offshore oil and gas platforms, desalination plants, chemical processing equipment, marine structures, and power generation systems where resistance to harsh environments and high mechanical loads is critical.
Selection depends on factors such as load requirements, environmental exposure, bolt size, and applicable standards. For corrosive or high-pressure environments, S32750 is preferred due to its high strength and resistance to stress corrosion cracking.
Super Duplex Steel S32750 Washers are a critical choice for industries demanding extreme corrosion resistance and structural reliability in bolted assemblies. Their engineered performance ensures long-term stability in offshore, chemical, and high-pressure environments.
For technical specifications, bulk procurement, or custom manufacturing requirements, KK Fasteners provides engineering support and global export services tailored to industrial project needs. Contact the technical team to request a quotation or detailed datasheet.
