UNS N07718 is the Unified Numbering System designator for the precipitation-hardening nickel-chromium-niobium superalloy commercially branded Inconel 718 or Alloy 718. Composition: 50-55% Ni, 17-21% Cr, 2.8-3.3% Mo, 4.75-5.50% Nb+Ta. European equivalent is Werkstoff Nr. 2.4668. The same alloy is the subject of ASTM A1014 for bolting and ASTM B637 for bar stock.

Is UNS N07718 the same as Inconel 718?

Yes. UNS N07718 is the generic Unified Numbering System designator; Inconel 718 is the Special Metals trade name. Other producers brand the same chemistry as Alloy 718. The chemistry, mechanical envelope, and heat treatment cycle are identical regardless of producer name.

What standards cover UNS N07718 bolting?

Bolting: ASTM A1014 / A1014M (industrial), SAE AS 7467 (aerospace procurement), SAE AMS 5663 (final aerospace bar condition). Pressure vessel: ASME PVP Code Case 1993-7. Mil-Spec: MS14181, AS3418, NAS1351 family. Bar stock: ASTM B637, SAE AMS 5662 (solution annealed), AMS 5663 (precipitation hardened).

What is the maximum service temperature for UNS N07718?

Approximately 705 °C (1300 °F). Above this temperature the γ″ (Ni₃Nb) phase coarsens and the alloy over-ages, losing strength. For continuous service above 705 °C, consider Haynes 282 (UNS N07208) or Waspaloy (UNS N07001).

UNS N07718 — Inconel 718 Chemistry, Bolting & Bar Specs

UNS N07718, Chemistry, Designators, and Bolting Standards

Inconel 718 / Alloy 718 / W.Nr 2.4668 / Nickel-Chromium-Niobium Precipitation-Hardening Superalloy

UNS N07718 is the Unified Numbering System designator for the precipitation-hardening nickel-chromium-niobium superalloy commercially branded Inconel 718 by Special Metals and Alloy 718 by other producers. In Europe the equivalent designator is Werkstoff Nr. 2.4668. The same alloy is the subject of ASTM A1014 for bolting components, ASTM B637 for bar and forging stock, SAE AMS 5662 (solution heat treated) and AMS 5663 (solution + precipitation hardened) for aerospace procurement, and ASME PVP Code Case 1993-7 for pressure-vessel service.

For Inconel 718 bolting: request a quote at +91-22-66157017, WhatsApp +91-22-66157017, or info@torqbolt.com. MTC 3.1 / 3.2 certifications, NACE MR0175 compliance, ITAR-controlled aerospace orders supported.

What is UNS N07718

UNS N07718 sits in the SAE/ASTM Unified Numbering System under the "N" prefix for nickel and nickel alloys. The five-digit code identifies a single specific nickel-chromium-niobium chemistry developed in the 1960s by INCO (now Special Metals) for high-temperature aerospace bolting, gas-turbine compressor discs, and oilfield downhole tools. The alloy strengthens through precipitation of γ″ (gamma double-prime, Ni₃Nb) and γ′ (gamma prime, Ni₃(Al,Ti)) phases during age hardening, giving 185 ksi tensile strength at room temperature that retains 145 ksi at 1200 °F (650 °C).

UNS N07718 Chemistry (per ASTM A1014 Table 1)

Element	Composition (mass %)
Nickel + Cobalt	50.0 – 55.0
Chromium	17.0 – 21.0
Molybdenum	2.80 – 3.30
Niobium + Tantalum	4.75 – 5.50
Titanium	0.65 – 1.15
Aluminum	0.20 – 0.80
Cobalt, max	1.0
Carbon, max	0.08
Iron	Remainder

Element

Composition (mass %)

Nickel + Cobalt

50.0 – 55.0

Chromium

17.0 – 21.0

Molybdenum

2.80 – 3.30

Niobium + Tantalum

4.75 – 5.50

Titanium

0.65 – 1.15

Aluminum

0.20 – 0.80

Cobalt, max

1.0

Carbon, max

0.08

Iron

Remainder

Niobium content is the discriminating element: it pushes UNS N07718 into the γ″-strengthened family vs UNS N06625 (Inconel 625) which is primarily solid-solution strengthened. The deliberately slow γ″ precipitation kinetics give UNS N07718 the best weldability of any precipitation-hardening superalloy.

Mechanical Properties (Age-Hardened Condition)

Property	Room Temperature	1200 °F (650 °C)
Tensile strength, min	185 ksi (1275 MPa)	145 ksi (1000 MPa)
0.2% yield strength, min	150 ksi (1035 MPa)	125 ksi (860 MPa)
Elongation, min	12 %	12 %
Reduction of area, min	15 %	15 %
Brinell hardness	331 – 444 HBW	-
Stress rupture (100 ksi)	-	23 hours minimum

Property

Room Temperature

1200 °F (650 °C)

Tensile strength, min

185 ksi (1275 MPa)

145 ksi (1000 MPa)

0.2% yield strength, min

150 ksi (1035 MPa)

125 ksi (860 MPa)

Elongation, min

12 %

Reduction of area, min

15 %

Brinell hardness

331 – 444 HBW

Stress rupture (100 ksi)

23 hours minimum

Standards That Govern UNS N07718

Standard	Product Form / Scope
ASTM A1014 / A1014M	Bolting components: bolts, studs, screws (this site)
ASTM B637	Bar, forgings, and forging stock for elevated-temperature service
SAE AMS 5662	Aerospace bar & forging, solution heat treated
SAE AMS 5663	Aerospace bar & forging, solution + age hardened (final bolt condition)
SAE AMS 5664	Aerospace bar & forging, higher-strength solution + age hardened
SAE AMS 5596	Sheet, strip, and plate, solution treated
SAE AMS 5597	Sheet, strip, and plate, age hardened
SAE AS 7467	Aerospace bolts / screws, 185 ksi tensile, stress-rupture rated
MS14181 / AS3418 / NAS1351	Mil-Spec aerospace bolt part numbers in UNS N07718
ASME PVP Code Case 1993-7	Pressure-vessel code case authorizing UNS N07718 bolting

Standard

Product Form / Scope

ASTM A1014 / A1014M

Bolting components: bolts, studs, screws (this site)

ASTM B637

Bar, forgings, and forging stock for elevated-temperature service

SAE AMS 5662

Aerospace bar & forging, solution heat treated

SAE AMS 5663

Aerospace bar & forging, solution + age hardened (final bolt condition)

SAE AMS 5664

Aerospace bar & forging, higher-strength solution + age hardened

SAE AMS 5596

Sheet, strip, and plate, solution treated

SAE AMS 5597

Sheet, strip, and plate, age hardened

SAE AS 7467

Aerospace bolts / screws, 185 ksi tensile, stress-rupture rated

MS14181 / AS3418 / NAS1351

Mil-Spec aerospace bolt part numbers in UNS N07718

ASME PVP Code Case 1993-7

Pressure-vessel code case authorizing UNS N07718 bolting

Where to Order UNS N07718 Bolting

For finished bolting in UNS N07718 / Inconel 718, browse the ASME B18 dimensional families covered on this site:

Related Specifications

Surface Treatments

Xylan 1070 / 1014 / 1400 / 1424

Xylar 2 / 101

Geomet 321 / 500 / 720

SermaGard 1105 / 1280

Dacromet 320 / 500

TakeCoat 1000 Ceramic

Delta Tone/Seal

Magnigard

MolyKote

Sherardized

Zinc-Cobalt (ASTM B840)

Zinc-Nickel (ASTM B841)

Certifications

ISO 9001 - 2015 Certified
PED 2014/68/EC
NACE MR0175/ISO 15156-2
NORSOK M-650
DFAR
MERKBLATT AD 2000 W2/W7/W10