[ Stud Bolts ]
A193 B16 Stud Bolts
Patriot Bolt machines ASTM A193 Grade B16 stud bolts from certified chromium-molybdenum-vanadium bar for joints that run too hot for B7. The vanadium addition and a higher tempering temperature help B16 resist creep and stress relaxation, so the joint holds its clamp load through years of hot service.
We make B16 studs to your purchase order or drawing and supply matching A194 Grade 7 heavy hex nuts. Every order ships with mill test reports traceable to the heat.
[ Quick Specs ]
A193 B16 Stud Bolts at a Glance
- Specification
- ASTM A193 / ASME SA193 Grade B16
- Material
- Cr-Mo-V alloy steel (UNS K14072), quenched and tempered
- Strength
- 125 ksi min tensile, 105 ksi min yield (2-1/2 in and under)
- Hardness
- 321 HBW / 35 HRC max
- Service
- Typically up to about 1100 °F
- Matching nut
- A194 Grade 7 heavy hex
Why Engineers Specify A193 B16 Stud Bolts
Above roughly 800 °F, B7 studs slowly relax and the joint loses preload. B16 is made to keep that load.
- Vanadium strengthening. 0.25 to 0.35 percent vanadium and higher molybdenum improve creep and relaxation resistance.
- Higher temper. B16 is tempered at 1200 °F minimum, above its service temperature, so its properties stay stable in use.
- Full strength. The same 125 ksi minimum tensile as B7 in sizes up to 2-1/2 in.
- Hot-service nuts. Pair with A194 Grade 7 nuts, which are also rated for elevated temperature.
A193 B16 Stud Bolt Specifications
ASTM A193 sets B16 properties by diameter.
| Diameter | Tensile, min | Yield (0.2%), min | Elongation, min | Reduction of area, min | Hardness, max |
|---|---|---|---|---|---|
| 2-1/2 in and under | 125 ksi | 105 ksi | 18% | 50% | 321 HBW / 35 HRC |
| Over 2-1/2 to 4 in | 110 ksi | 95 ksi | 17% | 45% | 321 HBW / 35 HRC |
| Over 4 to 8 in | 100 ksi | 85 ksi | 16% | 45% | 321 HBW / 35 HRC |
Use the allowable stresses in your design code for the actual service temperature.
A193 B16 Chemical Composition
| Element | Weight % |
|---|---|
| Carbon | 0.36–0.47 |
| Manganese | 0.45–0.70 |
| Phosphorus | 0.035 max |
| Sulfur | 0.040 max |
| Silicon | 0.15–0.35 |
| Chromium | 0.80–1.15 |
| Molybdenum | 0.50–0.65 |
| Vanadium | 0.25–0.35 |
| Aluminum | 0.015 max |
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.
Use a high-temperature anti-seize on B16 studs to help removal after service.
Applications and Industries
- Power generation: Steam turbine casings, high-pressure steam piping and boiler valve bonnets. See Power Generation.
- Refining: Hot hydrocarbon lines and heater piping. See Petrochemical & Refining.
- Combined-cycle and cogeneration plants: Heat recovery steam generator flanges.
Certification and Traceability
Patriot Bolt is ISO 9001:2015 certified. Each B16 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 grade symbol and our identification, as the specification requires.
Compare B16 with other bolting grades in our Fastener Materials Matrix.
A193 B16 Stud Bolts FAQ
When should I use B16 instead of B7?
Use B16 when the joint runs above about 800 °F or must hold clamp load for long periods without retorquing. B7 is the economical choice below that range.
Which nut goes with B16?
ASTM A194 Grade 7 heavy hex nuts. Older specifications may also list Grade 4, which ASTM withdrew in 2017.
What is the maximum temperature for B16?
B16 is typically used up to about 1100 °F. The exact limit comes from the allowable stresses in your design code.
Can you make B16 studs to my drawing?
Yes. We machine B16 studs in any diameter, length and thread from 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.