Inconel 718 washers are precipitation-hardened nickel alloy fastening components designed for extreme environments where high strength, oxidation resistance, and thermal stability are critical. Commonly manufactured to standards such as ASTM B637 and ASME specifications, these washers are widely used in aerospace assemblies, oil & gas equipment, and high-temperature power generation systems.

| Material | Nickel-Chromium Alloy (Inconel 718) |
|---|---|
| Grade | UNS N07718 |
| Standards | ASTM B637, ASME SB637, DIN 125, DIN 9021, ISO 7089 |
| Size Range | M3 to M100 / 1/8" to 4" |
| Type | Flat Washers, Spring Washers, Plain Washers, Custom Washers |
| Thread Compatibility | Metric, UNC, UNF, BSW |
| Surface Finish | Plain, Passivated, Polished |
| Hardness | Rockwell C 36–44 (heat-treated condition) |
| Tensile Strength | Up to 1240 MPa |
| Grade | C | Mn | Si | S | Cu | Fe | Ni | Cr |
| Inconel 718 | 0.08 max | 0.35 max | 0.35 max | 0.015max | 0.30 max | – | 50.00 – 55.00 | 17.00 – 21.00 |
| Element | Density | Melting Point | Tensile Strength | Yield Strength (0.2%Offset) | Elongation |
| Inconel 718 | 8.2 g/cm3 | 1350 °C (2460 °F) | Psi – 1,35,000 , MPa – 930 | Psi – 75,000 , MPa – 482 | 45 % |
| STANDARD | WERKSTOFF NR. | UNS |
| Inconel 718 | 2.4668 | N07718 |
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" |
- |
- |
- |
Inconel 718 washers are used in high-performance applications where strength, heat resistance, and corrosion protection are essential for maintaining joint integrity under extreme conditions.
Inconel 718 washers are typically produced through precision CNC machining or hot forging, followed by solution annealing and age-hardening heat treatment to achieve required mechanical properties. Dimensional accuracy is maintained through calibrated inspection tools aligned with ISO and DIN standards.
Quality assurance includes hardness testing, tensile verification, surface finish inspection, and PMI (Positive Material Identification) for alloy validation. Each batch is traceable through heat numbers and inspection reports.
KK Fasteners follows ISO 9001-certified processes, ensuring consistent product quality and compliance with international standards such as ASTM and ASME. Documentation including mill test certificates (MTC) and third-party inspection reports can be provided upon request.

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.
Inconel 718 washers are high-strength nickel alloy washers designed to distribute load and maintain joint stability in extreme environments. They are widely used in high-temperature and high-pressure applications due to their excellent mechanical strength, fatigue resistance, and oxidation protection.
Yes, Inconel 718 washers offer excellent corrosion resistance against oxidation, seawater, and a wide range of chemicals. Their nickel-chromium composition allows them to perform reliably in aggressive environments where standard stainless steel fasteners may degrade.
Inconel 718 washers are typically manufactured according to ASTM B637 and ASME SB637 material standards. Dimensional standards such as DIN 125, DIN 9021, and ISO 7089 are also commonly followed for flat and plain washer configurations.
The correct washer depends on operating temperature, load conditions, and exposure environment. Inconel 718 is ideal for high-temperature and cyclic stress applications, especially where standard materials like stainless steel cannot maintain strength or resist creep deformation.
A reliable supplier should provide ISO-certified manufacturing, full material traceability, and compliance with ASTM standards. Experience in global exports, quality documentation, and customization capability are key factors when evaluating suppliers like KK Fasteners.
For critical applications where failure is not an option, material selection and manufacturing precision make a measurable difference. KK Fasteners supplies Inconel 718 washers with verified material properties, tight tolerances, and export-ready documentation. Contact the engineering team to request a quote or discuss custom specifications for your project.