Nickel based Inconel 718 is a precipitation hardened, gamma double prime strengthened alloy. Also referred to as an age hardening process, precipitation hardened alloys such as Inconel 718 are to be heat treated, which in turn aids to increase the yield strength of malleable materials. In the case of superalloy products like Inconel 718 Fasteners, heat treatment is known to cause yield strength anomaly, thus providing the alloy with excellent strength at high temperatures.

Inconel 718 Fasteners

Inconel 718 Fasteners

On exposure to heat most typical alloys, tend to lose their tensile strength properties and succumb to creep. However, unlike conventional alloys, the combination of nickel along with precipitation hardening of the alloy is why Inconel 718 threaded rod can not only resist becoming susceptible to creep but as mentioned previously the yield strength anomaly leads to the increase of its yield strength. Hence, the Inconel 718 forging is an alloy that can be employed in the construction of jet engines and gas turbines.


As per specification ASTM B637, the Alloy Inconel 718 nuts are not only tested but must also comply with the mechanical as well as the chemical requirements mentioned here. The tests conducted on the ASTM B637 UNS N07718 hex bolts include Tension testing in addition to hardness testing and stress rupture test. Apart from having high tensile strength the Alloy 718 studs have excellent impact strength and can be used for subzero applications as well.

Equivalent material grade of Alloy 718 studs

Product European ASTM UNS
Alloy 718 2.4668 B637 N07718

Inconel 718 Fasteners Chemical Equation

  Ni Cr Fe Mo Ti Al Si Cu Mn Cb+Ta C B
Min. 52.0 18.0 19.0 3.0 0.9 0.5 - - - 5.0 0.05 0.009
Max. Balance - - - - - 0.35 0.1 0.35 - - -

ASTM B637 UNS N07718 hex bolts Mechanical Strength

Ultimate Tensile Strength, ksi 202
Temperature (in °F) 70
0.2 % Yield Strength, ksi 170

Alloy Inconel 718 nuts Dimensional Chart

Alloy Inconel 718 nuts Dimensional Chart

Minimal Size / Dia. of Basic Major Thread F G H
Across Flats Width

Across Corners Width

Thick
Max Basic Min Min Max Basic Min Max
2-3/4 2.7500 4.125 4-1/8 3.988 4.546 4.763 2-3/8 2.319 2.431
1/4 .2500 .438 7/16 .428 .488 .505 7/32 .212 .226
5/16 .3125 .500 1/2 .489 .557 .577 17/64 .258 .273
3/8 .3750 .562 9/16 .551 .628 .650 21/64 .479 .337
1/2 .5000 .750 3/4 .736 .840 .866 7/16 .427 .448
7/16 .4375 .688 11/16 .675 .768 .794 3/8 .365 .385
9/16 .5625 .875 7/8 .861 .982 1.010 31/64 .473 .496
7/8 .8750 1.312 1-5/16 1.269 1.447 1.516 3/4 .724 .776
5/8 .6250 .938 15/16 .922 1.051 1.083 35/64 .535 .559
3/4 .7500 1.125 1-1/8 1.088 1.240 1.299 41/64 .617 .665
1 1.0000 1.500 1-1/2 1.450 1.653 1.732 55/64 .831 .887
1-1/8 1.1250 1.688 1-11/16 1.631 1.859 1.949 31/32 .939 .999
1-3/8 1.3750 2.062 2-1/16 1.994 2.273 2.382 1-11/64 1.138 1.206
2 2.0000 3.000 3 2.900 3.306 3.464 1-23/32 1.675 1.763
1-1/2 1.500 2.250 2-1/4 2.175 2.480 2.598 1-9/32 1.245 1.ASTM A194 GR. 8
1-5/8 1.6250 2.438 2-7/16 2.356 2.686 2.815 1-25/64 1.353 1.429
2-1/4 2.2500 3.375 3-3/8 3.263 3.719 3.897 1-15/16 1.890 1.986
1-3/4 1.7500 2.625 2-5/8 2.538 2.893 3.031 1-1/2 1.460 1.540
2-1/2 2.5000 3.750 3-3/4 3.625 4.133 4.330 2-5/32 2.105 2.209

Inconel 718 Threaded Rod material specification

Lengths 3 to 6 Millimetre
Material Inconel Alloy 718
Standards ASTM B166 / ASME SB166
Sizing Ranges M02 upto M152.4
Threads: BSF, METRIC, UNF, UNC, or as per needs
In Form of: Threading, Hex, Round, Square as per Gauge Etc.
Most Used Types Inconel 718 Threaded Tod, Tie Rods, Double Ended Studs etc.