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Stainless Steel 310/310S Washers are engineered fastening components designed for extreme temperature and oxidation-resistant applications where standard stainless steels fail. Manufactured from high-chromium, high-nickel austenitic alloys, these washers maintain structural integrity in environments exceeding 1000°C, making them essential in furnace systems, petrochemical processing units, and heat treatment plants.
These washers distribute load evenly across bolted joints, preventing surface damage and improving fastening stability under thermal expansion conditions. Conforming to international standards such as ASTM A240, DIN 125, and ISO 7089, they ensure compatibility across global engineering systems.
KK Fasteners supplies these washers to industrial clients across multiple continents, offering consistent dimensional accuracy, traceable material certification, and reliable export logistics for critical applications.
| Parameter | Details |
|---|---|
| Material | Stainless Steel 310, 310S |
| Grade | UNS S31000, UNS S31008 |
| Size Range | M3 to M100 / 1/8” to 4” |
| Standards | DIN 125, DIN 9021, ISO 7089, ASTM A240, ASTM F593 |
| Type | Flat Washers, Plain Washers, Spring Washers, Custom Washers |
| Finish | Plain, Polished, Pickled, Passivated |
| Thread Compatibility | Metric, UNC, UNF |
| Hardness | 150–200 HB (approx.) |
| Temperature Resistance | Up to 1100°C (intermittent service) |
| Grade | C | Mn | Si | P | S | Cr | Mo | Ni | N |
| SS 310 | 0.015 max | 2 max | 0.015 max | 0.020 max | 0.015 max | 24.00 – 26.00 | 0.10 max | 19.00 – 21.00 | 54.7 min |
| SS 310S | 0.08 max | 2 max | 1.00 max | 0.045 max | 0.030 max | 24.00 – 26.00 | 0.75 max | 19.00 – 21.00 | 53.095 min |
| Density | Melting Point | Tensile Strength | Yield Strength (0.2%Offset) | Elongation |
| 7.9 g/cm3 | 1402 °C (2555 °F) | Psi – 75000 , MPa – 515 | Psi – 30000 , MPa – 205 | 40 % |
| STANDARD | WERKSTOFF NR. | UNS | JIS | BS | GOST | AFNOR | EN |
| SS 310 | 1.4841 | S31000 | SUS 310 | 310S24 | 20Ch25N20S2 | – | X15CrNi25-20 |
| SS 310S | 1.4845 | S31008 | SUS 310S | 310S16 | 20Ch23N18 | – | X8CrNi25-21 |
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" |
- |
- |
- |
Stainless Steel 310/310S washers are primarily used in high-temperature and oxidation-prone industrial environments where maintaining joint integrity is critical under thermal stress.
Production of SS 310/310S washers typically involves precision stamping or CNC machining, followed by controlled finishing processes such as pickling and passivation. Each batch undergoes dimensional inspection using calibrated gauges to ensure compliance with DIN and ISO tolerances.
Mechanical properties are verified through hardness testing, while surface quality is checked for uniformity and defects. Material traceability is maintained through heat numbers and mill test certificates.
At KK Fasteners, quality protocols align with ISO 9001 standards, ensuring every shipment meets international compliance requirements and client-specific specifications.
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Stainless Steel 310/310S washers are high-temperature resistant fastening components made from austenitic stainless steel grades. They are designed to distribute load in bolted joints while maintaining strength and stability in extreme heat and oxidizing environments such as furnaces, heat treatment systems, and petrochemical equipment.
SS 310 contains higher carbon content, which improves high-temperature strength and creep resistance. SS 310S has lower carbon content, which enhances weldability and reduces the risk of carbide precipitation. The selection depends on whether the application prioritizes strength under heat or weld-friendly performance.
These washers are commonly manufactured in compliance with international standards such as DIN 125, ISO 7089, ASTM A240, and ASTM F593. These standards ensure consistent dimensions, mechanical properties, and compatibility with global bolting systems used in industrial applications.
They are widely used in furnace equipment, petrochemical plants, heat exchangers, power generation units, oil & gas refineries, and chemical processing systems. Their main role is to maintain joint integrity under continuous high temperatures and oxidizing conditions.
A reliable manufacturer should provide material traceability, ISO-certified quality systems, accurate dimensional compliance, and export documentation. Buyers should also evaluate technical support, testing capabilities, and global supply experience before selecting a supplier like KK Fasteners.
For high-temperature fastening applications where material performance cannot be compromised, precision and traceability are critical. KK Fasteners supplies Stainless Steel 310/310S washers with verified specifications and consistent export quality. To discuss project requirements or request technical documentation, connect with the team for a detailed quotation and lead time assessment.
