The PREN value of Inconel 625 is about 40, which is much better than austenitic stainless steel grade 316, which sums up to 20. A higher PREN value indicates that the alloy has a higher chance of resisting pitting. A PREN score of over 35 would mean the material has excellent resistance to pitting. Pitting resistance behaviour of the Inconel 625 Fasteners is attributed to the addition of molybdenum to its alloy.

Inconel 625 Fasteners

Inconel 625 Fasteners

Fasteners produced from Wrought non-ferrous alloy grades such as the Inconel 625 are covered by the specification ASTM F468. While any fastener manufactured under this specification for e.g. - ASTM F468 uns n06625 nuts are required to conform to the specified chemistry, a set of mechanical tests are also to be conducted on these fasteners. Per usual, the tests undergone by the Inconel 625 hex bolt in order to determine its mechanical properties include - hardness test, a test for both tensile strength and yield strength in addition to a test fo elongation.


The fasteners like the Inconel 625 stud bolts could be either cold formed or they could be hot formed. Another option is that they could be machined from a suitable material. This corrosion resistant, Inconel 625 threaded rod is used to stabilise objects produced from either metal, wood, or any other materials that are typically seen in applications involving building, plumbing and general maintenance. Virtually immune to chloride stress related corrosion cracking the Alloy 625 washers are a thin disk shaped object that can be used to evenly distribute the load or stress of a threaded nut and bolt.

Inconel 625 Fasteners Specifications, sizes and dimensions

Standards ASTM B166 / ASME SB166
Material Inconel Alloy 625
Sizing Ranges M02 upto M152.4
Threads: METRIC, BSW, UNC, UNF, BSF, or as per needs
Lengths 3 to 6 Millimetre
Testing Inconel 625 Bolting Certificates: EN 10204 / 3.1
In Form of: Threading, Hex, Round, Square as per Gauge Etc.
Most Used Types Inconel 625 Threaded Tod, Tie Rods, Double Ended Studs etc.

Inconel 625 stud bolts Chemical Element

Chemical Compounds In Percentage (%)
Nickel, Ni 58.0 min
Carbon, C 0.10 max
Sulphur, S 0.015 max
Manganese, Mn 0.50 max
Silicon, Si 0.50 max
Iron, Fe 5.0 max
Copper, Cu -

Mechanical Behaviour of UNS N06625 Hex bolt

Elongation 42.5 %
Melting Point 1350 °C (2460 °F)
Tensile Strength Psi – 1,35,000 , MPa – 930
Density 8.4 g/cm3
Yield Strength (0.2%Offset) Psi – 75,000 , MPa – 517

Alloy 625 Nuts Equivalent grades

Product British European ASTM UNS
Inconel 625 BS 3076 NA 21 2.4856 B166 N06625