Hastelloy X Washers are nickel-based alloy fastening components engineered for extreme heat, oxidation resistance, and mechanical stability under thermal cycling. Manufactured primarily to ASTM B435 and AMS 5754 standards, they are widely used in gas turbines, aerospace assemblies, industrial furnaces, and chemical processing equipment where conventional stainless steel grades fail under sustained high-temperature exposure. These washers maintain structural integrity in environments exceeding 900°C while resisting carburization and stress corrosion cracking. Their unique combination of nickel, chromium, and iron provides balanced strength and oxidation resistance, making them suitable for critical load distribution in high-performance assemblies.

KK Fasteners supplies Hastelloy X Washers to global OEMs and maintenance contractors, ensuring full material traceability and dimensional precision for mission-critical applications. Each batch is engineered for consistent performance across aerospace, energy, and petrochemical systems where failure is not an option.
For engineers and procurement teams, Hastelloy X Washers are not just fastening components—they are reliability enablers in thermally aggressive systems where long-term stability is essential.
| Parameter | Specification |
|---|---|
| Material | Hastelloy X (UNS N06002) |
| Grade | Nickel-Chromium-Iron-Molybdenum Alloy |
| Size Range | M3 to M64 / 1/8" to 2.5" |
| Thickness | 0.5 mm to 10 mm (customizable) |
| Standards | ASTM B435, AMS 5754, DIN 125, ISO 7089 |
| Thread Compatibility | Metric (M), UNC, UNF |
| Surface Finish | Bright annealed, pickled, polished |
| Hardness | 85–95 HRB (typical) |
| Tensile Strength | Up to 690 MPa (approx.) |
| Type Variants | Flat washers, spring washers, precision washers |
| Hastelloy X | Ni | C | Mo | Mn | Si | Fe | P | S | Co | Cr |
| Balance | 0.02 max | 26.0-30.0 | 1.0 max | 0.10 max | 2.0 max | 0.040 max | 0.030 max | 1.0 max | 1.0 max |
| Density | Melting Point | Yield Strength (0.2%Offset) | Tensile Strength | Elongation |
| 9.2 g/cm3 | 1370 °C (2500 °F) | Psi – 51,000, MPa – 350 | Psi -1,10,000, MPa -760 | 40 % |
| STANDARD | UNS | WERKSTOFF NR. |
| Hastelloy X | N10665 | 2.4617 |
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" |
- |
- |
- |
Hastelloy X Washers are used in high-temperature and corrosive environments where structural reliability is critical. These components are widely integrated into aerospace, energy, and industrial processing systems.
Hastelloy X Washers are manufactured using precision stamping and CNC-assisted blanking processes followed by controlled heat treatment to achieve stable microstructure. The alloy is carefully processed to avoid carbide precipitation, ensuring long-term thermal stability.
Each batch undergoes dimensional inspection, hardness verification, and surface integrity testing to ensure compliance with ASTM B435 and AMS 5754 standards. Lot traceability is maintained from raw material procurement to final dispatch.
KK Fasteners implements ISO 9001-certified quality systems, ensuring every washer meets strict aerospace and industrial performance benchmarks. Surface finish consistency and edge burr control are verified through multi-stage inspection protocols, making the product suitable for critical engineering applications.

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Hastelloy X Washers are nickel-based alloy fastening components designed for high-temperature and oxidation-prone environments. They distribute load in bolted joints while maintaining strength and stability in aerospace, turbine, and furnace applications where conventional stainless steel washers would degrade.
Hastelloy X offers a unique combination of nickel, chromium, iron, and molybdenum, delivering excellent oxidation resistance, high creep strength, and structural stability at temperatures above 900°C. These properties make it suitable for thermal cycling and aggressive combustion environments.
Hastelloy X Washers are typically manufactured in compliance with ASTM B435 and AMS 5754 standards. Dimensional specifications often follow DIN 125 and ISO 7089 depending on application requirements in industrial and aerospace assemblies.
These washers are widely used in gas turbines, aerospace exhaust systems, industrial furnaces, petrochemical processing units, and power generation equipment. They are selected for applications requiring resistance to heat, oxidation, and mechanical stress.
A reliable supplier should provide ISO-certified manufacturing, full material traceability, and compliance with ASTM/AMS standards. Engineering support, inspection reports, and global export capability are also essential. KK Fasteners supports industrial buyers with certified production and international supply reliability.
For engineering-grade fastening reliability in extreme thermal environments, Hastelloy X Washers deliver proven performance and dimensional stability. KK Fasteners supports global OEMs with precision manufacturing, certified materials, and export-ready supply chains tailored for critical applications.
Request a technical quote or connect with our engineering team to discuss custom specifications and bulk supply requirements for your project.