Inconel 625 Fasteners Supplier & Exporter
Most fasteners are picked by size and strength, but that changes when the joint is sitting in seawater, chloride service or a chemical process line. Corrosion starts to matter just as much as load. For this type of work, Alloy 625 is one of the grades customers ask us for quite often. At Kalpataru Piping, we supply Inconel 625 bolts, nuts, studs, screws, threaded rods and washers for projects in India and overseas. On drawings and purchase orders, the material is usually written as UNS N06625 or Werkstoff 2.4856. The molybdenum and niobium in the alloy are a big part of why 625 performs well where pitting and crevice corrosion are a concern. Depending on what the customer asks for, we can also supply EN 10204 Type 3.1 material certificates, traceability records and other test documents. If the same project needs Inconel 625 pipes, flanges or fittings, those can be supplied in the same alloy as well, while this page is mainly about choosing the right fastener type, size, thread and finish for the job.
Why Inconel 625 Is Used for Fasteners
Alloy 625 is usually chosen when a joint has to deal with corrosion as well as load. Chloride service, seawater and chemical process equipment are common examples because the alloy has strong resistance to pitting and crevice corrosion. Molybdenum and niobium also give the alloy useful strength without relying on age hardening. For a fastener, the final choice still depends on the actual joint, including temperature, preload, exposure, coating and the mating materials.
Inconel 625 Fasteners Types
Inconel 625 Fasteners Specifications
| Parameter | Details |
|---|---|
| Material Grade | Inconel 625 / Alloy 625 |
| UNS | N06625 |
| Werkstoff No. | 2.4856 |
| Material Standard | ASTM F468/F468M for bolts, cap screws and studs; ASTM F467/F467M for nuts; washers to the applicable dimensional and material standard |
| AMS | AMS 5666 where applicable to bar, forging, extrusion or ring starting material |
| Available Sizes | ASTM F468 inch-series bolts, cap screws and studs generally cover 1/4 in. to 1-1/2 in.; ASTM F468M metric fasteners cover M6 to M36. Other sizes can be quoted to another suitable standard or customer drawing. |
| Thread Types | UNC, UNF, UNEF, BSW, BSF, Metric, where available |
| Stud Types | Double-End Studs, Fully Threaded Studs, Tap-End Studs |
| Stud Ends | Chamfered, Flat, Rounded, Saw-Cut |
| Screw Head Styles | Hex cap, socket head, button head and flat countersunk where covered by the selected standard; other head styles by customer drawing |
| Bolt Neck Types | Square Neck, Ribbed/Knurled Neck, depending on bolt type |
| Threaded Rod | Right-Hand, Left-Hand, or Right- and Left-Hand |
| Threaded Rod Condition | Cold Drawn, Annealed, Threaded, as specified |
| Manufacturing Process | Hot Forged, Cold Forged, CNC Machined |
| Screw Tip Styles | Cup Point, Cone Point, Dog Point, Flat Point, Oval Point, as specified |
| Washer Type / Form | Flat, spring or other washer forms supplied to the applicable dimensional and material standard stated on the order |
| Surface Finish | Bright or machined finish, passivation or project-specified coating where technically suitable |
| Temperature Capability | Suitable for elevated-temperature service, but the allowable operating temperature depends on load, environment, exposure time and bolted-joint design |
Inconel 625 Fasteners Chemical Composition
| Element | Content |
|---|---|
| Nickel (Ni) | 58.0% min |
| Chromium (Cr) | 20.0–23.0% |
| Molybdenum (Mo) | 8.0–10.0% |
| Niobium + Tantalum (Nb + Ta) | 3.15–4.15% |
| Iron (Fe) | 5.0% max |
| Carbon (C) | 0.10% max |
| Manganese (Mn) | 0.50% max |
| Silicon (Si) | 0.50% max |
| Sulfur (S) | 0.015% max |
| Phosphorus (P) | 0.015% max |
Additional chemistry limits for Alloy 625: Aluminium 0.40% max, Titanium 0.40% max and Cobalt 1.0% max when determined.
Mechanical Properties of Inconel 625 Fasteners
| Mechanical Properties | Values |
|---|---|
| Tensile Strength | 827 MPa min |
| 0.2% Yield / Proof Stress | 414 MPa min |
| Elongation | 30% min |
| ASTM F468 Marking | F468AC |
| Hardness Range | 85 HRB to 35 HRC |
Mechanical acceptance values depend on the ordered ASTM F468 or F468M alloy designation and product size. The purchase order and current standard govern final acceptance.
Physical Properties of Inconel 625 Alloy
| Properties | Unit | Value |
|---|---|---|
| Density | lb/in³ | 0.305 |
| Density | g/cm³ | 8.44 |
| Melting Range | °F | 2350–2460 |
| Melting Range | °C | 1290–1350 |
| Magnetic Permeability | 15.9 kA/m | 1.0006 |
| Curie Temperature | °F | Below −320 |
| Curie Temperature | °C | Below −196 |
Equivalent Grades and Designations for Inconel 625
The designations below are commonly used for Alloy 625. The purchase order should still state the governing material and fastener standard, because an equivalent alloy name does not by itself define the finished fastener requirements.
| Standard / Designation | Inconel 625 Equivalent |
|---|---|
| UNS | N06625 |
| Werkstoff Nr. | 2.4856 |
| EN | NiCr22Mo9Nb / 2.4856 |
| JIS | NCF 625 |
| GOST | ХН75МБТЮ |
| AFNOR | NC 22 DNb |
Inconel 625 Fasteners Size Range
ASTM F468 inch-series bolts, hex cap screws and studs cover nominal diameters from 1/4 in. to 1-1/2 in.; socket head cap screws also include smaller sizes covered by the standard. ASTM F468M and F467M cover metric sizes M6 to M36. Sizes outside these scopes should be quoted against another suitable standard or a customer drawing.
| Fastener Type | Available Sizes |
|---|---|
| Inconel 625 Heavy Hex Nuts | As specified by the applicable standard or customer drawing |
| Inconel 625 Hex Nuts | As specified by the applicable standard or customer drawing |
| Inconel 625 Hex Bolts | As specified by the applicable standard or customer drawing |
| Inconel 625 Hex Cap Screws | As specified by the applicable standard or customer drawing |
| Inconel 625 Socket Head Cap Screws | As specified by the applicable standard or customer drawing |
| Inconel 625 Flat Washers | As specified by the applicable standard or customer drawing |
| Inconel 625 Stud Bolts | As specified by the applicable standard or customer drawing |
HSN and Customs Classification of Inconel 625 Fasteners
Alloy 625 is a nickel-base alloy, so heading 7318 for fasteners of iron or steel should not be used by default. Nickel fasteners are generally considered under heading 7508, "Other articles of nickel." The exact Indian ITC-HS or HSN subheading should be confirmed for the specific article and current tariff before invoicing or import/export documentation.
| Product Description | HS Heading | Classification Note |
|---|---|---|
| Inconel 625 Bolts, Screws & Similar Fasteners | 7508 | Nickel-base fastener; verify the exact Indian ITC-HS subheading for the article |
| Inconel 625 Nuts | 7508 | Verify the exact Indian ITC-HS subheading for the specific nut |
| Inconel 625 Washers | 7508 | Verify the exact Indian ITC-HS subheading for the specific washer |
| Inconel 625 Studs / Threaded Fasteners | 7508 | Verify the exact Indian ITC-HS subheading for the specific threaded article |
Testing and Certification for Inconel 625 Fasteners
Testing should follow the purchase order and the standard being supplied. Depending on the order, this can include chemical analysis, mechanical testing, dimensional inspection and positive material identification. EN 10204 Type 3.1 certificates can be supplied, while Type 3.2 or third-party witnessed inspection should be agreed before production.
Inconel 625 Fasteners Price List
Inconel 625 fastener pricing changes with the alloy surcharge, fastener type, diameter, length, thread, quantity, manufacturing route, finish and inspection requirements. A static per-kilogram price can become outdated quickly, so this page should use current quote-based pricing instead of a fixed market range. Send the required fastener type, size, quantity, standard and certification requirement for the latest per-piece or per-kilogram quotation.
FAQs About Inconel 625 Fasteners
What is the difference between Inconel 625 fasteners and Incoloy 825 fasteners?
Both are nickel-based alloys offering corrosion resistance, but their performance profiles differ:
- Inconel 625 fasteners: Higher strength, stable at elevated temperatures, excellent oxidation resistance and acid resistance. Preferred in aerospace, offshore and chemical plants.
- Incoloy 825 fasteners: Good corrosion resistance particularly in sulfuric and phosphoric acid environments, but lower high-temperature strength compared to 625. Used in chemical processing, oil and gas and pollution control.
In summary, 625 is more robust and heat-resistant, whereas 825 is more cost-effective for moderate corrosion conditions.
What standards apply to Inconel 625 fasteners?
Inconel 625 fasteners standards are mainly ASTM F467 (nuts), ASTM F468 (bolts, screws and studs) and ASTM B446 (bar stock used to make fasteners). Dimensional standards include ASME B18.2.1, DIN 931/933 for bolts and DIN 934 for nuts. Forms threads are based on UNC, UNF, ISO Metric, BSW and BSF.
What is the operating temperature range of Inconel 625 fasteners?
The temperature range of Inconel 625 fasteners is between cryogenic (below minus 196 degrees Celsius) down to about 982 degrees Celsius (1800 degrees Fahrenheit). This unique selection gives them an application in either cryogenic storage systems or in hot industrial furnaces, gas turbines and chemical reactors.
Get an Inconel 625 Fastener Quote
Send the fastener type, diameter, thread, length, quantity, finish and required standard. If there is a drawing or project specification, attach that as well so the quote can be checked against the correct material and dimensional requirements.
