| Standard | ASTM A193 / ASME B18.31.2 dimensional reference · A193M Grade B16 |
|---|---|
| Material | ASTM A193 Grade B16 chromium-molybdenum-vanadium alloy steel |
| Strength Grade | B16 |
| Size Range | M12-M64 / 1/2"-4" |
| Surface Treatment | Plain / Black Oxide / Phosphate / Project-Approved High-Temperature Coating |
Product Description
ASTM A193/A193M Grade B16 stud bolts are quenched-and-tempered chromium-molybdenum-vanadium alloy-steel pressure bolting components for sustained elevated-temperature service. They are used in steam piping, valves, turbine casings, boiler and heat-recovery equipment, hot process flanges and pressure vessels where the governing code or project specification calls for B16.
B16 is not simply a stronger version of B7. The two grades can share the same minimum room-temperature tensile and yield values in some diameter ranges, but B16 has distinct chemistry and heat treatment intended for more demanding creep and stress-relaxation conditions. Selection must follow the applicable design code, allowable-stress table, temperature history, exposure time and joint design.
ASTM A194 Grade 7 is a common nut starting point for B16 systems, but the complete assembly must be approved by the project. Specify thread series, dimensional reference, coating, temperature-rated lubricant, tightening method, marking, heat treatment and certificates together. B16 remains alloy steel rather than a corrosion-resistant nickel or stainless grade.
| Product type | ASTM A193 Grade B16 high-temperature stud bolts |
|---|---|
| Material standard | ASTM A193/A193M Grade B16 |
| Material family | Quenched and tempered chromium-molybdenum-vanadium alloy steel |
| Common nut pairing | ASTM A194 Grade 7 heavy hex nuts where approved by code and project |
| Size range | M12-M64 / 1/2 in-4 in |
| Thread and dimensions | UNC / 8UN / metric; ASME B18.31.2 or customer drawing as applicable |
| Surface condition | Plain / Black oxide / Phosphate / Project-approved high-temperature coating |
| Temperature boundary | Determined from governing code allowables, pressure, exposure time and joint design; no single universal ASTM A193 service limit |
| Documentation | MTC, chemistry, heat treatment, tensile, yield, hardness, dimensions and heat traceability as specified |
| Parameter | M4 | M5 | M6 | M7 | M8 | M10 | M12 | M14 | M16 | M18 | M20 | M22 | M24 | M27 | M30 | M33 | M36 | M39 | M42 | M45 | M48 | M52 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| P | 0.7 | 0.8 | 1 | 1 | 1|1.25 | 1.25|1.5 | 1.25|1.5|1.75 | 1.5|2 | 1.5|2 | 1.5|2.5 | 1.5|2.5 | 1.5|2.5 | 2|3 | 2|3 | 2|3.5 | 2|3.5 | 3|4 | 3|4 | 3|4.5 | 3|4.5 | 3|5 | 3|5 |
| b1 | 5 | 6.5 | 7.5 | 9 | 10 | 12 | 15 | 18 | 20 | 22 | 25 | 28 | 30 | 35 | 38 | 42 | 45 | 50 | 52 | 58 | 60 | 65 |
| ds/max | 4 | 5 | 6 | 7 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 22 | 24 | 27 | 30 | 33 | 36 | 39 | 42 | 45 | 48 | 52 |
Engineering references
Selection
B16 studs are used for steam valves, piping flanges, turbine casings and boiler equipment when sustained-temperature strength and clamp-load retention govern.
Power generation fastenersHot process flanges and pressure closures may specify B16 where code allowables and creep or relaxation behavior make it preferable to B7.
Oil and gas fastenersReview chemistry, diameter-based strength, heat treatment, creep, allowable stress and nut pairing before approving any substitution.
Compare ASTM A193 B7 and B16Assembly
Manufacturing
FAQ
Use B16 when the governing code or project specifies it for sustained elevated-temperature service where creep, stress relaxation or high-temperature allowable stress drives selection. Do not choose from a universal temperature cutoff alone.
ASTM A194 Grade 7 heavy hex nuts are a common starting point for B16 systems. The final nut grade must follow the governing code, piping class, temperature and project bill of materials.
No. Geometry may match, but chemistry, heat treatment, diameter-based mechanical properties and elevated-temperature behavior differ. Any substitution requires engineering and purchaser approval.
B16 is alloy steel, not stainless or nickel alloy. Coating or a different bolting alloy must be selected when process or environmental corrosion governs.
Send ASTM edition, diameter, length, thread, design temperature, pressure code or piping class, nut grade, coating, lubricant, test and certificate scope, quantity and delivery requirement.
Send the ASTM edition, design temperature, code, diameter, length, thread, nut grade, coating, lubricant, inspection scope and quantity. We can quote traceable B16 and Grade 7 stud-nut assemblies.
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