Patriot Bolt machines Monel K-500 stud bolts from certified round bar for marine, subsea and oil-tool joints that need more strength than Monel 400. Alloy K-500 (UNS N05500) is the age-hardenable version of Monel 400. Aluminum and titanium additions let it reach about three times the yield strength of 400 while keeping its corrosion resistance in seawater.
We make K-500 studs to ASTM F468, ASTM B865 or your drawing. Every order ships with mill test reports traceable to the heat.
Monel K-500 Stud Bolts at a Glance
- Also called
- Alloy K-500 · UNS N05500 · W.Nr. 2.4375
- Material specs
- ASTM B865 bar · ASTM F468 studs · ASTM F467 nuts
- Strength
- 130 ksi min tensile; 90 ksi min yield to 7/8 in., 85 ksi from 1 to 1-1/2 in. (ASTM F468)
- Hardness
- 24–37 HRC (ASTM F468)
- Configurations
- Fully threaded, double-end and tap-end
Why Engineers Specify Monel K-500 Stud Bolts
Monel 400 has excellent seawater resistance but modest strength. K-500 keeps the same nickel-copper chemistry and adds age hardening, so studs can carry much higher preload in marine and subsea joints.
- Strength. Aged K-500 reaches 130 ksi minimum tensile under ASTM F468.
- Seawater. It has low corrosion rates in fast-flowing seawater, which is why it is used for pump shafts and marine hardware.
- Corrosion fatigue and erosion. It combines the corrosion resistance of 400 with better fatigue and erosion resistance.
- Non-magnetic. Useful for subsea instruments and oil-tool assemblies.
Monel K-500 Stud Bolt Specifications
ASTM F468 covers nonferrous bolts and studs, listing K-500 as alloy Ni 500. ASTM B865 covers K-500 bar. F468 covers diameters to 1-1/2 in.; larger studs are usually ordered to B865 bar and your drawing.
| ASTM F468 Ni 500, diameter | Tensile, full size | Yield (0.2%), min | Elongation, min | Hardness |
|---|---|---|---|---|
| 1/4 to 7/8 in. | 130–180 ksi | 90 ksi | 20% | 24–37 HRC |
| 1 to 1-1/2 in. | 130–180 ksi | 85 ksi | 20% | 24–37 HRC |
Matching nuts are covered by ASTM F467 (Ni 500). Put the specification and condition on your purchase order.
Monel K-500 Chemical Composition
| Element | Weight % |
|---|---|
| Nickel (+ cobalt) | 63.0 min |
| Copper | 27.0–33.0 |
| Aluminum | 2.30–3.15 |
| Titanium | 0.35–0.85 |
| Iron | 2.0 max |
| Manganese | 1.5 max |
| Silicon | 0.5 max |
| Carbon | 0.25 max |
| Sulfur | 0.01 max |
Typical limits for UNS N05500. The mill test report for your heat is the controlling document.
Stud Configurations
- Fully threaded studs, threaded end to end, for flange bolting where grip length varies.
- Double-end studs, threaded on both ends with an unthreaded center.
- Tap-end studs, with one end made to thread into a tapped hole.
Nickel-copper alloys can gall. Use a compatible thread lubricant or anti-seize.
Applications and Industries
- Subsea and offshore: Subsea flange, valve and instrument studs. See Oil & Gas.
- Oil tools: Downhole and non-magnetic drilling assemblies.
- Marine and pumps: Pump, propeller and seawater system bolting. See Industrial & Manufacturing.
Certification and Traceability
Patriot Bolt is ISO 9001:2015 certified. Each Monel K-500 order includes mill test reports traceable to the heat, along with a certificate of conformance to the specification on your purchase order.
Compare Monel K-500 with other bolting grades in our Fastener Materials Matrix.
Monel K-500 Stud Bolts FAQ
What is the difference between Monel 400 and K-500?
K-500 adds aluminum and titanium so it can be age hardened. It has about three times the yield strength of Monel 400 with similar corrosion resistance.
Which ASTM specification covers K-500 studs?
ASTM F468 covers K-500 bolts and studs (alloy Ni 500), and ASTM F467 covers the matching nuts. K-500 bar is covered by ASTM B865.
Is Monel K-500 magnetic?
No. K-500 is non-magnetic, which is one reason it is used in subsea instruments and oil tools.
Do you make matching nuts?
Yes. We also machine Monel K-500 nuts and heavy hex bolts.
Request a Quote
Send us the stud configuration, diameter, length, thread, specification and quantity, or upload your drawing. Our team will confirm the material and lead time. Call (281) 581-0176 or request a quote.
Also in Monel K-500: Heavy hex bolts · Nuts · Socket head cap screws · All stud bolts