Monel K500
Stud Bolts
UNS N05500
Why Monel K500 for Stud Bolts
Monel K500 (UNS N05500) is produced by adding aluminium (2.30–3.15%) and titanium (0.35–0.85%) to the Monel 400 Ni-Cu base, then age-hardening at 593°C to precipitate a coherent Ni₃(Al,Ti) gamma-prime phase throughout the matrix. The result is ≥1000 MPa tensile strength and ≥690 MPa yield — more than 3× that of annealed Monel 400 — with no loss of corrosion resistance. For stud bolts in ASME B16.5 flanged pressure joints, this combination is unique: seawater-immune alloy at bolt-grade strength.
K500 stud bolts excel in subsea wellhead assemblies, offshore riser clamps, and desalination plant pressure vessel nozzles — applications where the joint is permanently immersed in seawater and must carry full Class 600–2500 bolt loads without corrosion-assisted relaxation. Unlike stainless steel stud bolts that pit and seize in chloride service within months, K500 studs in the same environment show no measurable corrosion after years of service.
Akbar Fasteners Pvt. Ltd. machines K500 stud bolts from ASTM B865 certified UNS N05500 bar stock, XRF PMI-verifies every lot on receipt, threads on CNC lathes to DIN 13 metric or UNC/UNF inch pitch, and supplies with matched K500 heavy hex nuts from the same certified heat — eliminating galvanic risk at the joint interface.
| Element | Min % | Max % | Typical |
|---|---|---|---|
| Nickel + Cobalt | 63.0 | — | ~65% |
| Copper (Cu) | — | Balance | ~30% |
| Aluminium (Al) | 2.30 | 3.15 | ~2.7% |
| Titanium (Ti) | 0.35 | 0.85 | ~0.6% |
| Iron (Fe) | — | 2.0 | ~1.5% |
| Manganese (Mn) | — | 1.5 | — |
| Carbon (C) | — | 0.25 | — |
| Silicon (Si) | — | 0.50 | — |
| Sulfur (S) | — | 0.010 | — |
| Ultimate Tensile Strength | ≥ 1000 MPa |
| 0.2% Proof Stress (YS) | ≥ 690 MPa |
| Elongation | ≥ 20% |
| Hardness | ≤ 35 HRC |
| Condition | Age Hardened |
Monel K500 Stud Bolt Configurations
All configurations machined from ASTM B865 age-hardened UNS N05500 bar. Custom end lengths, thread engagement, and ASME PCC-1 torque calculations on request.
Fully Threaded Stud
Thread runs the full length — the standard for ASME B16.5 flanged pressure joints. Both ends receive a heavy hex nut. Available Class 150–2500. Most common K500 stud bolt configuration for marine and offshore service.
Equal-End Stud Bolt
Threaded ends of equal length with a plain centre shank. Standard for raised-face and ring-joint ASME B16.5 assemblies. Plain shank confirms correct nut engagement length visually during tightening.
Unequal-End Stud
One end screws permanently into a tapped valve body or equipment nozzle; the nut is applied on the other. Thread engagement per ASME PCC-1. Used on subsea manifold nozzles and high-integrity flange closures.
High-Pressure Compact
Short heavy-section studs for Class 1500 and 2500 ring-joint flanges. Higher thread engagement, heavy hex nuts. Typical for M52 and above in subsea wellhead and FPSO riser assemblies requiring maximum clamping load.
Long Shank / Thermal Stud
Extended plain shank for applications where thermal expansion or vibration demands a longer free-running section. Common in desalination plant pressure vessels and marine heat exchanger covers with large face separations.
Custom / Non-Standard
Special diameters, left-hand thread, inch UNC/UNF, ACME thread profile, lengths to 3,000mm, and drawing-specific configurations. Send drawing to sales@akbarfasteners.in for pricing.
ASME B16.5 Stud Bolt Lengths — Class 150 to 2500
Standard lengths per ASME B16.5 / ASME B18.31.2 including two K500 heavy hex nuts. Lengths in mm. Compare with our Hastelloy B3 stud bolt dimension table for grade selection. Custom lengths to 3,000mm on request.
| Dia. (M) | Thread Pitch | Class 150 (mm) | Class 300 (mm) | Class 600 (mm) | Class 900 (mm) | Class 1500 (mm) | Class 2500 (mm) |
|---|---|---|---|---|---|---|---|
| METRIC — DIN 13 THREAD FORM (UNS N05500 · ASTM B865) | |||||||
| M12 | 1.75 mm | 90 | 100 | 115 | 125 | 140 | — |
| M16 | 2.0 mm | 100 | 110 | 125 | 140 | 160 | — |
| M20 | 2.5 mm | 110 | 125 | 140 | 160 | 185 | 215 |
| M24 | 3.0 mm | 125 | 140 | 160 | 180 | 210 | 245 |
| M30 | 3.5 mm | 145 | 165 | 190 | 215 | 255 | 300 |
| M36 | 4.0 mm | 170 | 195 | 225 | 260 | 305 | 360 |
| M42 | 4.5 mm | 195 | 225 | 265 | 305 | 355 | 420 |
| M48 | 5.0 mm | 220 | 260 | 300 | 345 | 400 | 475 |
| M56 | 5.5 mm | — | 290 | 340 | 390 | 455 | 545 |
| M64 | 6.0 mm | — | 325 | 380 | 440 | 515 | 615 |
| M72 | 6.0 mm | — | 360 | 425 | 490 | 575 | — |
| M80 – M100 | 6.0 mm | — | — | Custom | Custom | Custom | — |
* Lengths indicative per ASME B16.5. Confirmed on order against flange raised-face or ring-joint dimensions. Custom to 3,000mm. Inch UNC/UNF available. Send RFQ to sales@akbarfasteners.in
Standards We Manufacture & Test To
Same heat-traceability and documentation system as our Hastelloy B3 stud bolts — full MTC, COC, PMI, NABL test reports on every order.
Industry Applications
The combination of ≥1000 MPa bolting strength, permanent seawater immunity, non-magnetic behaviour, and NACE MR0175 compliance makes K500 the specification-of-choice in demanding marine and offshore flanged joint service.
Offshore / Subsea
riser clamps · manifolds
Seawater Systems
heat exchanger nozzles
Marine Platforms
deck equipment bolting
Oil & Gas
Xmas tree assemblies
Chemical Processing
alkylation units
Naval & Defence
minesweeper flanges
Power Generation
condenser nozzles
Pump & Valve Bodies
seawater valve nozzles
Complete Documentation Package
Heat & Lot Traceable
Conformance
100% Lots Verified
Tensile · Hardness
TÜV · BV · Lloyds
Related Monel K500 & Alloy Fasteners
Matched material throughout the joint — nuts, washers, and rods from the same certified UNS N05500 heat. Or choose the right alloy for a different service environment.
Monel K500 Fasteners
Full K500 range — hex bolts, hex nuts, washers, socket screws — all age-hardened, all from same certified heat as these stud bolts.
View Page →Monel K500 Threaded Rods
Fully threaded rods in K500, M6–M100 up to 3,000mm. For marine hanger rods and structural tie rods in seawater service.
View Page →Hastelloy B3 Stud Bolts
For HCl and reducing acid service where Monel K500 is not specified. Near-zero corrosion in HCl at all concentrations. ASME B16.5 Class 150–2500.
View Page →Monel 400 Fasteners
Annealed Ni-Cu for lower-strength marine joints. Same seawater and HF resistance as K500 at a lower cost where bolt loads permit.
View Page →Need Monel K500
Stud Bolts Now?
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