Oxidation-resistant to 1093°C, immune to chloride stress-corrosion cracking, and fully ductile at cryogenic temperature — supplied with EN 10204 3.1 traceability from our Mumbai works.
When a bolted joint has to survive glowing furnace hardware one day and cryogenic transfer lines the next, ordinary stainless steel simply gives up. Inconel 600 fasteners — known globally as Alloy 600, UNS N06600 and Werkstoff Nr. 2.4816 — are the answers engineers reach for. This nickel-chromium-iron austenitic alloy holds a minimum of 72% nickel and 14–17% chromium. The chromium forms a self-repairing oxide film that resists oxidation and carburisation in sulphur-free atmospheres, while the nickel content puts the alloy outside the composition band in which chloride stress corrosion cracking occurs. At Unifit Fastener, we manufacture the full bolting family in Alloy 600 — hex bolts, heavy hex nuts, stud bolts, threaded rods, washers, screws and anchor fasteners — from M3 to M100 and 3/16" to 4", to ASTM B166 and ASME SB166 for bar stock, ASTM B564 / ASME SB564 for forged items, and ASTM F467 / F468 for finished nuts and bolts. Every batch is PMI-verified, hardness-tested and released with an EN 10204 3.1 mill test certificate, so your inspection team never has to take our word for it. Whether you are re-bolting a hydrogen reformer, a nuclear steam generator or a food-grade evaporator, you get the right metallurgy, the right thread class and documented traceability — the first time.
Inconel 600 fasteners are threaded fastening components machined, forged or cold-headed from a solid-solution-strengthened nickel-chromium-iron alloy. Unlike precipitation-hardened grades such as Inconel 718, Alloy 600 derives its strength from alloying itself rather than heat-treatment ageing, which gives it an unusually wide working window. It is fully ductile at cryogenic temperature and resists scaling in oxidising atmospheres to approximately 2000°F (1093°C). Load-bearing capability is the narrower limit: like every solid-solution nickel alloy, Alloy 600 relaxes under sustained load well below its oxidation ceiling, so bolted joints above roughly 650°C must be designed on creep-rupture and stress-relaxation data rather than on room-temperature yield. Tell us the metal temperature and hold time at enquiry and we will confirm whether the joint needs 600, 601 or a 718 stud.
Specifying Inconel 600 is rarely about raw tensile numbers — a quenched-and-tempered alloy steel bolt is stronger at room temperature. It is about retained strength and joint integrity after thousands of hours at temperature. Carbon and alloy steels scale and lose preload; austenitic stainless steels crack under chloride and caustic attack; Alloy 600 keeps its microstructure stable, keeps its clamp load, and does not embrittle when the plant is shut down and thermally cycled back up.
Unifit Fastener manufactures more than 40 distinct fastener forms in Alloy 600. Everything below is produced in-house or from our own certified bar stock — we do not re-badge trading material.
Parameter | Specification |
|---|---|
Material Grade | Inconel 600 / Alloy 600 / Nickel Alloy 600 |
UNS Designation | UNS N06600 |
Werkstoff Number | 2.4816 |
Governing Standards | ASTM B166, ASTM B564, ASTM F467, ASTM F468, ASTM F2281, ASME SB166, ASME SB564, ASME SF467, ASME SF468 |
Dimensional Standards | ASME B18.2.1, ASME B18.2.2, ASME B18.3, ASME B18.6.3, ASME B18.21.1, DIN 931, DIN 933, DIN 934, DIN 125, DIN 7991, DIN 976, ISO, JIS, BS, GB, IS |
Size Range (Bolts) | M3 – M100 | 3/16" to 4" | custom sizes on request |
Size Range (Nuts) | M3 – M56 | 3/16" to 2" |
Size Range (Washers) | M3 – M56 | 3/16" to 2" |
Length Range | 3 mm to 200 mm and above (custom lengths available) |
Thread Types | UNC, UNF, UN, 8UN, BSW, BSF, metric coarse, metric fine, or as specified |
Thread Configuration | ASME B1.1 2A/3A – 2B/3B inch unified; ASME B1.13M 6g–6H metric coarse |
Head Styles | Hex, heavy hex, square, round, flange, countersunk, socket, T-head, triangular, dome |
Manufacturing Route | Cold heading, hot forging, CNC turning, thread rolling, insert tapping, solution annealing |
Surface Finish | Plain / bright, passivated, pickled, black oxide, Xylan, PTFE, cadmium, zinc, galvanised |
Tolerance | OEM / ODM to drawing; ±0.03 mm achievable on machined features |
Test Certificate | EN 10204 / 3.1 mill test certificate; PED 97/23/EC and AD 2000 W2 on request |
Certification | Dual certified to ASTM and ASME codes |
Delivery | Standard products 7–15 days; custom products 2–4 weeks |
Country of Origin | India (Mumbai, Maharashtra) |
Composition limits per ASTM B166 / ASME SB166, expressed as weight percentage.
Element | Symbol | Weight % (per ASTM B166) | Metallurgical Role |
|---|---|---|---|
Nickel | Ni | 72.00 min | Chloride SCC and caustic resistance; austenitic stability |
Chromium | Cr | 14.00 – 17.00 | Forms the protective, self-repairing oxide film |
Iron | Fe | 6.00 – 10.00 | Balances cost and workability |
Carbon | C | 0.15 max | Controlled to limit carbide precipitation |
Manganese | Mn | 1.00 max | Deoxidiser; sulphur control |
Silicon | Si | 0.50 max | Deoxidiser; assists oxidation resistance |
Copper | Cu | 0.50 max | Residual limit |
Sulphur | S | 0.015 max | Restricted to protect hot workability |
Property | Metric Value | Imperial Value |
|---|---|---|
Tensile Strength (min) | 550 – 655 MPa | 80,000 – 95,000 psi |
Yield Strength (0.2% offset, min) | 240 – 310 MPa | 35,000 – 45,000 psi |
Elongation in 2" | 30 – 40% min | 30 – 40% min |
Density | 8.47 g/cm³ | 0.306 lb/in³ |
Melting Range | 1354 – 1413 °C | 2470 – 2580 °F |
Maximum Continuous Service Temperature | ~1093 °C | ~2000 °F |
Modulus of Elasticity | ~207 GPa | ~30 × 10⁶ psi |
Typical Hardness (annealed) | 65 – 85 HRB | 65 – 85 HRB |
Magnetic Response | Non-magnetic (austenitic) | Non-magnetic (austenitic) |
*Values are typical for annealed material in fastener sections. Cold-worked and hot-finished conditions vary; certified values for your specific heat appear on the accompanying mill test certificate.*
Standard | Werkstoff Nr. | UNS | JIS | BS | GOST | AFNOR | EN |
|---|---|---|---|---|---|---|---|
Inconel 600 | 2.4816 | N06600 | NCF 600 | NA 13 | ХН78Т (28-2,5-1,5) | NC15FE11M | NiCr15Fe |
Bolt Type | Common Standard | Typical Use Case |
|---|---|---|
Hex bolts / hex head bolts | ASME B18.2.1, DIN 931/933 | General structural and flange bolting |
Heavy hex bolts | ASME B18.2.1 | High-pressure flanged joints |
Socket head cap screws | ASME B18.3, DIN 912 | Compact machined assemblies, valve internals |
Countersunk / flat head screws | DIN 7991, ISO 10642 | Flush-mounted covers and liners |
Flange head bolts | DIN 6921 | Vibration-prone joints without separate washer |
12-point flange bolts | ASME/OEM drawing | High-torque, restricted-access assemblies |
Carriage bolts | DIN 603 | Through-bolted plate and cladding work |
Eye bolts, J bolts, U bolts, hook bolts | DIN 580, custom | Lifting, pipe support, tube clamping |
Anchor bolts & sleeve anchors | ASTM B564 / drawing | Foundation and equipment anchoring |
Set screws & grub screws | DIN 913–916 | Shaft and collar location |
Self-drilling & self-tapping screws | DIN 7504 / 7981 | Sheet, duct and cladding fixings |
Torx and machine screws | ISO 14579 | Tamper-resistant and precision assemblies |
Nut Type | Common Standard | Typical Use Case |
|---|---|---|
Hex nuts | ASTM F467, DIN 934 | Standard mating nut for Alloy 600 bolting |
Heavy hex nuts | ASTM F467, ASME B18.2.2 | Pressure-boundary flange joints |
Hex jam / thin nuts | DIN 439 | Locking and clearance-limited joints |
Nyloc / nylon insert lock nuts | DIN 985 | Vibration resistance below polymer temperature limit |
All-metal lock nuts & prevailing torque nuts | DIN 980 | High-temperature vibration locking |
Dome / acorn / cap nuts | DIN 1587 | Thread protection and finished appearance |
Coupling nuts | DIN 6334 | Threaded rod extension |
Wing nuts, T-nuts, knurled thumb nuts | DIN 315 / custom | Hand-adjusted access panels |
Square nuts, castle nuts, slotted nuts | DIN 557 / DIN 935 | Channel fixing and cotter-pin retention |
Weld nuts, rivet nuts, insert nuts | DIN 928 / custom | Blind and sheet-metal fastening |
Flange nuts & 12-point nuts | DIN 6923 / OEM | Load spreading and high torque |
Stud / Rod Type | Description |
|---|---|
Fully threaded stud bolts | Continuous thread both ends — the standard ASME B16.5 flange stud |
Double-ended studs (tap-end / nut-end) | Plain centre body with threaded ends for tapped-hole assemblies |
Reduced-shank stud bolts | Waisted body for controlled elongation and improved fatigue life |
Half-threaded and partial-thread studs | Where a plain grip length is required through the joint |
Threaded rods / all-thread rod | DIN 976 in 1 m and 3 m lengths, cut to size |
Tie rods and tie bars | Furnace and duct restraint hardware |
Trapezoidal threaded rod | Motion and adjustment assemblies in hot zones |
Coil rods and continuous threaded studs | Refractory anchoring and heater support |
See our dedicated Inconel stud bolts page and the general stud bolts range for dimensional charts, or read the guide on types of stud bolts.
Washer Type | Standard | Function |
|---|---|---|
Plain / flat washers | DIN 125, DIN 126, ASME B18.21.1 | Load distribution under bolt head or nut |
Spring / split lock washers | DIN 127 | Vibration resistance in moderate-temperature joints |
Tab washers and lock plates | DIN 93 / 463 | Positive mechanical locking |
Belleville / conical spring washers | DIN 6796 | Preload maintenance through thermal cycling |
Star / serrated / tooth lock washers | DIN 6797/6798 | Anti-rotation on painted or coated surfaces |
Square, ogee and dock washers | Custom / F436 style | Timber, structural and heavy plate work |
Sealing and bonded washers | Custom | Fluid-tight fixings on panels and roofing |
Related pages: Inconel washers, nickel alloy washers, and the reference article on types of washers.
Alloy 600 bolting is specified wherever heat, chlorides, caustics or thermal cycling would defeat a conventional fastener. These are the sectors that order from us most often.
Industry | Where Inconel 600 Fasteners Are Used | Why This Alloy Wins |
|---|---|---|
Heat treatment & furnaces | Muffles, retorts, baskets, radiant tube supports, furnace door hardware | Retains strength and resists scaling to 1093°C |
Chemical processing | Heaters, stills, bubble towers, evaporators, reactor internals | Handles organic and inorganic acids and caustics |
Petrochemical & refining | Reformer bolting, flare hardware, hot flanged joints | Resists carburisation and thermal cycling |
Power generation | Boiler internals, superheater supports, ducting and expansion joints | Stable microstructure under long-term heat |
Nuclear engineering | Steam generator components, reactor internals, high-purity water systems | Non-magnetic with proven high-purity water resistance |
Aerospace & gas turbine | Exhaust liners, jet engine hardware, lockwire and clamp fittings | High-temperature fatigue and oxidation resistance |
Pulp, paper & textiles | Digesters, bleaching lines, dyeing machinery | Chloride and caustic resistance in wet service |
Marine & offshore | Splash-zone hardware, seawater heat exchangers, condenser fixings | Immune to chloride stress corrosion cracking |
Food, dairy & pharma | Evaporators, sterilisers, clean-in-place skids | Non-contaminating, cleanable passive surface |
Cryogenic & LNG | Transfer line clamps, vacuum jacket hardware | No ductile-to-brittle transition at low temperature |
For a broader view of where nickel superalloy bolting is deployed, read our guide on the applications and uses of Inconel fasteners and the advantages of nickel alloy fasteners.
Use this grid to confirm that Alloy 600 is the right grade before you release the purchase order — over-specifying to 718 or 625 can double your bolting cost with no service benefit.
Grade | Min Yield Strength | Corrosion Focus | Max Service Temp | Best Suited To |
|---|---|---|---|---|
Inconel 600 | 35 ksi (240 MPa) | Oxidation, chloride SCC, caustics | ~2000°F (1093°C) | Furnaces, heat exchangers, general hot bolting |
Inconel 601 | 30 ksi (205 MPa) | Oxidation & carburisation (Al-bearing) | ~2200°F (1204°C) | Extreme oxidising and cyclic-heat service |
Inconel 625 | 60 ksi (414 MPa) | Pitting & crevice (PREN ≈ 45) | ~1800°F (982°C) | Seawater, acids, offshore and subsea bolting |
Inconel 718 | 150 ksi (1034 MPa) | Good general resistance | ~1300°F (704°C) | High-strength turbine and downhole fasteners |
Incoloy 800/800HT | 30 ksi (205 MPa) | Oxidation & carburisation | ~1800°F (982°C) | Cost-balanced high-temperature process hardware |
Compare directly with our Inconel 601 fasteners, Inconel 625 fasteners, Inconel 718 fasteners, Inconel X-750 fasteners and Incoloy 800 / 800HT fasteners.
Criterion | Inconel 600 | Stainless Steel 316 | Monel 400 |
|---|---|---|---|
Nominal nickel content | 72% min | 10 – 14% | 63% min |
Max service temperature | ~1093°C | ~870°C (scaling limit) | ~540°C |
Chloride SCC resistance | Excellent — effectively immune | Poor above ~60°C | Excellent |
Caustic / alkali resistance | Excellent | Moderate | Excellent |
Seawater performance | Good | Moderate (pitting risk) | Excellent |
Relative cost index | High | Low | High |
Magnetic response | Non-magnetic | Essentially non-magnetic | Slightly magnetic below Curie point |
Best-fit duty | Hot process + chlorides | General corrosion service | Seawater and hydrofluoric service |
Also consider Monel 400 fasteners, Hastelloy fasteners, duplex steel fasteners, super duplex fasteners and titanium fasteners where the duty is corrosion-led rather than temperature-led.
Test | Purpose | Availability |
|---|---|---|
Positive Material Identification (PMI) | Confirms alloy grade before dispatch | 100% of lots |
Chemical analysis (spectro) | Verifies composition against ASTM B166 | Per heat |
Tensile, yield and elongation | Confirms mechanical class | Per lot / per heat |
Hardness (Rockwell / Brinell) | Confirms condition after annealing | Per lot |
Ultrasonic testing (UT) | Internal flaw detection in billets and large studs | On request / per spec |
Dye penetrant (DP) testing | Surface crack detection | On request |
Intergranular corrosion (IGC) test | Confirms freedom from sensitisation | On request |
Dimensional & thread gauging | Go/no-go and profile verification | 100% sampling plan |
Third-party inspection | TÜV, BV, SGS, Lloyd's witness inspection | On request |
Standard | Scope for Inconel 600 Fasteners |
|---|---|
ASTM B166 / ASME SB166 | Nickel-chromium-iron alloy rod, bar and wire — the base stock standard |
ASTM B564 / ASME SB564 | Nickel alloy forgings — heavy hex heads, anchors and forged specials |
ASTM F467 / ASME SF467 | Nonferrous nuts for general use |
ASTM F468 / ASME SF468 | Nonferrous bolts, hex cap screws and studs for general use |
ASTM F2281 | Nickel alloy bolts, hex cap screws and studs for high-temperature service |
ASME B18.2.1 / B18.2.2 | Dimensional standards for inch bolts, screws and nuts |
ASME B1.1 / B1.13M | Unified inch and metric screw thread tolerance classes |
DIN 931 / 933 / 934 / 125 / 976 | Metric bolt, nut, washer and threaded rod dimensions |
EN 10204 3.1 | Mill test certificate issued by the manufacturer's independent inspection function |
PED 97/23/EC, AD 2000 W2 | Pressure equipment conformity documentation (on request) |
More context in our fasteners standards reference and the guide to ISO fastener standards.
Alloy 600 pricing is not a fixed per-kilogram figure, and any supplier quoting one without seeing your drawing is guessing. These are the variables that move a real quotation.
Cost Driver | Effect on Price |
|---|---|
LME nickel and chromium movement | The single largest input; raw material can be 60–70% of a finished fastener cost |
Size and section | Large-diameter studs and heavy hex nuts consume disproportionately more bar stock |
Standard vs custom geometry | Catalogue DIN/ASME items cost less than drawing-specific specials with new tooling |
Thread type and class | 3A/3B and fine threads require tighter control and add cost over 2A/2B |
Order quantity | Cold-headed volume runs are materially cheaper per piece than machined small batches |
Coating and surface treatment | Xylan, PTFE and passivation add per-piece processing |
Testing and TPI requirements | UT, IGC, cryogenic impact or witnessed inspection add cost and lead time |
Delivery urgency | Expedited turnaround supply carries a premium over planned procurement |
Send us the drawing, quantity, standard and test requirements and you will receive a line-itemised quotation — not a range.
Alloy 600 is unforgiving of shortcuts. Hot-work it outside the correct band and you lose ductility; heat-treat it between 1200°F and 1600°F and you sensitise the grain boundaries. Our process is built around those metallurgical constraints.
We supply Inconel 600 fasteners across India — Mumbai, Pune, Ahmedabad, Chennai, Hyderabad, Bangalore, Coimbatore, Jamnagar, Vadodara, Kolkata, Vizag and Pimpri-Chinchwad — and export to the UAE, Saudi Arabia, Qatar, Oman, Kuwait, Singapore, Malaysia, Indonesia, Vietnam, South Korea, Japan, Australia, the United States, Canada, Mexico, Brazil, the United Kingdom, Germany, Netherlands, Italy, Spain, Turkey, Egypt, Nigeria and South Africa.
Inconel 600 fasteners are suitable for continuous service up to approximately 2000°F (1093°C) in oxidising atmospheres. The alloy retains useful mechanical strength and resists scaling across that range, and it also performs down to cryogenic temperatures without a ductile-to-brittle transition.
No. Inconel 600 has a fully austenitic, face-centred cubic structure, which makes it non-magnetic in the annealed condition. This is why it is accepted for instrumentation housings, nuclear internals and other assemblies with magnetic permeability limits.
Yes, and they perform well against chloride stress corrosion cracking. However, in stagnant or crevice-prone seawater service, Inconel 625, super duplex or Monel 400 fasteners usually offer better pitting resistance for the money. We are happy to advise on the trade-off for your specific exposure.
Yes. Every consignment ships with an EN 10204 3.1 mill test certificate carrying the heat number, chemical analysis and mechanical test results. PED 97/23/EC and AD 2000 W2 documentation, PMI reports and third-party inspection releases are available on request.
Bolts and screws from M3 to M100 (3/16" to 4"), nuts and washers from M3 to M56 (3/16" to 2"), and lengths from 3 mm to 200 mm as standard. Larger diameters and non-standard lengths are produced to drawing.
Send us your drawing, standard and quantity — our engineering team will confirm grade suitability, thread class and lead time before quoting. No obligation, no generic price lists, no guesswork.
Speak to a Materials Engineer — call or WhatsApp us today.
Not sure which grade you need? Compare Inconel 601, 625 and 718, or contact our team for a recommendation.