[ Stud Bolts ]
Inconel 725 Stud Bolts
Patriot Bolt machines Inconel 725 stud bolts from certified ASTM B805 round bar. Alloy 725 (UNS N07725) is a nickel-chromium-molybdenum-niobium alloy with corrosion resistance close to Inconel 625. Age hardening raises its strength to roughly twice that of annealed 625.
We make Inconel 725 studs to the specification on your purchase order or to your drawing. Every order ships with mill test reports traceable to the heat.
[ Quick Specs ]
Inconel 725 Stud Bolts at a Glance
- Also called
- Alloy 725 · UNS N07725
- Material specs
- ASTM B805 bar · API 6ACRA · NACE MR0175 / ISO 15156-3
- Strength
- 150 ksi min tensile, 120 ksi min yield (API 6ACRA 120K, age hardened)
- Key elements
- 55–59% Ni, 19–22.5% Cr, 7–9.5% Mo, 2.75–4% Nb
- Configurations
- Fully threaded, double-end and tap-end
Why Engineers Specify Inconel 725 Stud Bolts
- Strength from heat treatment. 725 is strengthened by age hardening, not cold work, so ductility and toughness stay high at full strength.
- Sour service. It is listed in NACE MR0175 / ISO 15156-3 and resists sulfide stress cracking in H2S environments.
- Seawater and chlorides. Molybdenum and chromium give pitting and crevice resistance close to 625.
- High preload in corrosive joints. The yield strength lets studs carry far more load than annealed nickel alloys.
Inconel 725 Stud Bolt Specifications
Inconel 725 bar is produced to ASTM B805. Oil and gas orders often call for API 6ACRA, which sets properties for the age-hardened material.
| Specification and condition | Tensile, min | Yield (0.2%) | Elongation, min | Reduction of area, min |
|---|---|---|---|---|
| API 6ACRA 120K, age hardened | 150 ksi | 120–150 ksi | 20% | 35% |
Put the specification and strength level on your purchase order. Confirm stud size and preload with your engineer.
Inconel 725 Chemical Composition
| Element | Weight % |
|---|---|
| Nickel | 55.0–59.0 |
| Chromium | 19.0–22.5 |
| Molybdenum | 7.0–9.5 |
| Niobium | 2.75–4.0 |
| Titanium | 1.0–1.7 |
| Aluminum | 0.35 max |
| Carbon | 0.03 max |
| Manganese | 0.35 max |
| Silicon | 0.20 max |
| Phosphorus | 0.015 max |
| Sulfur | 0.010 max |
| Iron | Balance |
Limits per the current edition of the specification. 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 alloys can gall. Use a compatible thread lubricant or anti-seize on assembly.
Applications and Industries
- Sour oil and gas: Wellhead, tubing hanger and high-pressure flange studs in H2S and CO2 service. See Oil & Gas.
- Subsea: Bolting for subsea equipment exposed to seawater and cathodic protection.
- Chemical processing: High-strength joints in chloride and acid service. See Petrochemical & Refining.
Certification and Traceability
Patriot Bolt is ISO 9001:2015 certified. Each Inconel 725 order includes mill test reports traceable to the heat, along with a certificate of conformance to the specification on your purchase order.
Studs are marked with the material and our identification.
Compare Inconel 725 with other bolting grades in our Fastener Materials Matrix.
Inconel 725 Stud Bolts FAQ
How is Inconel 725 different from Inconel 625?
725 has corrosion resistance close to 625 but can be age hardened, reaching roughly twice the yield strength of annealed 625.
How is Inconel 725 different from Inconel 718?
Both are age hardenable. 725 has more molybdenum and chromium, giving better resistance to pitting, crevice corrosion and sour environments.
Which specifications cover Inconel 725 studs?
ASTM B805 covers UNS N07725 bar. Oil and gas orders often call for API 6ACRA and NACE MR0175 / ISO 15156-3.
Can you make Inconel 725 studs to my drawing?
Yes. We machine Inconel 725 studs in the diameter, length and thread on your drawing or purchase order.
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.