Inconel 718 Fasteners
Bolts, studs and specialty fasteners in Inconel 718 nickel superalloy — a -423 °F to 900 °F service window and up to 220 ksi room-temperature tensile strength in the collected NASA fastener-material table, with 1,240 MPa tensile strength quoted for specialty fasteners.
Last updated: 2026-11
Specifications
Inconel 718 is the nickel-chromium superalloy of the collected NASA fastener-design table for joints that combine cryogenic to elevated temperature with high strength: the table lists a useful design temperature limit of -423 to 900 °F (or the cadmium-plate limit when cadmium plated) and room-temperature ultimate tensile strength up to 220 ksi. A bolt-grade reference chart quotes 1,240 MPa tensile strength for specialty fasteners made from Inconel 718 — beyond the 1,220 MPa of metric Class 12.9 and explicitly not covered by ISO 898-1 — and an offshore-fastener reference notes Inconel 718 is often specified for high-strength bolting in critical subsea applications. One documented caution: hydrogen-embrittlement references describe Inconel 718 as susceptible to hydrogen embrittlement at high hydrogen pressures, with NASA testing documenting measurable ductility loss under high-pressure gaseous hydrogen.
| Designation | Inconel 718 (nickel-chromium superalloy; the collected sources use the Inconel 718 designation without a UNS callout) |
|---|---|
| Useful design temperature limit | -423 to 900 °F, or the cadmium-plate limit when cadmium plated (collected NASA fastener-material table, °F verbatim) |
| Ultimate tensile strength, room temperature | Up to 220 ksi (collected NASA fastener-material table, ksi verbatim) |
| Tensile strength, specialty fasteners | 1,240 MPa (collected bolt-grade chart; quoted as beyond Class 12.9 and not covered by ISO 898-1) |
| Hot strength | Short-time tensile 190.5 ksi at 80 °F, 164.5 ksi at 1200 °F, 145.5 ksi at 1300 °F (yield 153.5 / 145.0 / 133.0 ksi) — Special Metals INCONEL alloy 718 bulletin Table 20, 5/8-in. hot-rolled round annealed 1800 °F/1 hr and aged (°F/ksi verbatim); the bulletin's 1950 °F-treated 4-in. round ladder (Table 19) extends to 105.0 ksi tensile at 1500 °F |
| Surface treatment per source table | Passivated per QQ-P-35, or cadmium plated (temperature limit then reads "or cadmium plate limit") |
| Service environment evidence | High-strength bolting in critical subsea applications (offshore-platforms reference); pitting and crevice corrosion resistance in chloride-rich waters |
| Hydrogen caution | Susceptible to hydrogen embrittlement at high hydrogen pressures; NASA testing documented measurable ductility loss under high-pressure gaseous hydrogen (hydrogen-embrittlement reference) |
| MOQ / lead time | Not owner-confirmed for this family — confirmed at quotation |
| Test temperature (°F) | Tensile strength (ksi) | Yield strength, 0.2% offset (ksi) | Elongation (%) | Reduction of area (%) |
|---|---|---|---|---|
| Room | 198.0 | 163.0 | 21 | 30 |
| 600 | 183.5 | 156.0 | 16 | 34 |
| 1000 | 173.0 | 148.0 | 16 | 30 |
| 1200 | 160.0 | 140.0 | 15 | 25 |
| 1300 | 146.0 | 135.0 | 8 | 10 |
| 1400 | 123.5 | 116.0 | 5 | 10 |
| 1500 | 105.0 | 100.0 | 15 | 20 |
| Test temperature (°F) | Tensile strength (ksi) | Yield strength, 0.2% offset (ksi) | Elongation (%) | Reduction of area (%) |
|---|---|---|---|---|
| -320 | 237.0 | 173.5 | 26.0 | 27.0 |
| -60 | 201.5 | 158.0 | 23.0 | 33.5 |
| 80 | 190.5 | 153.5 | 22.0 | 32.5 |
| 1200 | 164.5 | 145.0 | 28.0 | 59.2 |
| 1300 | 145.5 | 133.0 | 22.0 | 34.0 |
- Row 4 (1200): The 1200 °F elongation (28.0 %) and reduction of area (59.2 %) print as shown in the collected text layer; the sister-table cross-check matched the strength pair token-for-token, the ductility pair is rendered as printed without a second printed source.
Materials
- Inconel 718 nickel-chromium superalloy
Ordering & documentation
Documents
Shipments are backed by Mill Test Certificate (MTC), Dimensional Report, Salt Spray Test Report on request, with full batch traceability from raw material to finished product. Quality management follows the owner-confirmed compliance list: ISO 9001:2015, RoHS, REACH. Exact document sets are confirmed on the order.
Quotation
- The fastener family (Inconel 718 Fasteners) plus the standard designation from your drawing — DIN / ISO / JIS / ASTM / ANSI, or a drawing for custom parts.
- Size (diameter and length), thread type (metric or inch), property class or grade, and coating or finish.
- Quantity per size and your target delivery date.
- Destination country, and any required documents (for example a mill test certificate) so the quote includes them.
Sample & supply
Minimum order quantities and lead times for this family are confirmed at quotation — send your sizes, grades and quantities on the RFQ and the quote will carry a firm schedule. Sample availability is confirmed with the quotation.
Storage & shipping
Parts are packed for export and shipped factory-direct to buyers in Europe, Asia, the Americas and the Middle East. Store fasteners dry and protected until installation, and keep coated parts in their packaging until use; specific packing and preservation requirements can be stated on the order and confirmed at quotation.
Frequently asked questions
Why choose Inconel 718 over a 12.9 alloy-steel bolt?
The collected bolt-grade chart notes standard carbon and alloy steel grades lose significant strength above 300 °C, while specialty materials such as Inconel 718 quote 1,240 MPa tensile strength — beyond Class 12.9 — and are not covered by ISO 898-1. Inconel 718 adds the cryogenic-to-900 °F service window of the collected NASA table, where alloy-steel grades and their platings do not qualify.
Is Inconel 718 suitable for hydrogen service?
Treat high-pressure hydrogen as a design gate: the collected hydrogen-embrittlement reference describes Inconel 718 as susceptible at high hydrogen pressures, with NASA-documented ductility loss under high-pressure gaseous hydrogen — while noting nickel-hydrogen battery cells using Inconel 718 pressure vessels have not experienced embrittlement problems in practice. State your hydrogen pressure on the RFQ so the joint is reviewed, not assumed.
What should an RFQ for Inconel 718 fasteners state?
State the designation (Inconel 718), fastener type and thread sizes, the service temperature range and environment (subsea, cryogenic, elevated temperature), required strength basis, and surface condition (passivated per QQ-P-35 or cadmium plated per the collected table). Commercial terms are confirmed at quotation.
Request a Quote
Get factory-direct pricing from the manufacturer.
What to include in your inquiry
- ✓ Standard and property class (e.g. DIN 912, ISO 4762, class 8.8) — or a drawing for custom parts.
- ✓ Sizes, lengths and thread type (metric or inch).
- ✓ Quantity per size and your target delivery date.
- ✓ Destination country, plus any coating or finish requirement.
- ✓ Any documents you need with the shipment (e.g. mill test certificate) so the quote includes them.
- ✓ Your inquiry goes straight to the factory team by email and gets a reply within 24 hours.
- ✓ Factory-direct pricing
- ✓ Standard and custom specifications
- ✓ Factory-direct export to buyers in Europe, Asia, the Americas and the Middle East
- ✓ Full fastener family support