ASTM A193 B16 Round Bar, SA 193 B16 Chrome-Moly-Vanadium Alloy Steel Bar for High-Temperature Bolting, Manufacturer & Exporter in India

ASTM A193 B16 round bar is chromium-molybdenum-vanadium alloy steel bar made to the Grade B16 chemistry of ASTM A193 / ASME SA193. It is the starting material for studs, bolts and threaded rods in high-temperature, high-pressure service, and is chosen over B7 where creep and stress-relaxation resistance matter. Minimum strength is 860 MPa tensile and 725 MPa yield up to 64 mm diameter. Jade Alloys stocks B16 round bar in Mumbai and exports worldwide with EN 10204 3.1 mill test certificates.
Buyers search for this material as A193 B16 round bar, SA 193 B16 round bar, B16 alloy steel bar or B16 bolt material. They all describe bar in B16 grade, normally bought to machine studs, double-end studs, heavy hex bolts and threaded rods for boilers, steam and gas turbines, valves, pressure vessels and flanged joints. We supply black hot-rolled, peeled and bright bar from [10-200 mm] diameter in 1000-6000 mm lengths or cut to size, in as-rolled, annealed or quenched-and-tempered condition. Also available as hex, square, flat, hollow and threaded bar. Check what is ex-stock, read about us, or see how the bar becomes stud bolts and ASTM A193 B16 bolts.
Strength
860 MPa tensile, 725 MPa yield (up to 64 mm)
Alloying
Cr 0.80-1.15, Mo 0.50-0.65, V 0.25-0.35
Hardness
321 HBW / 35 HRC max
Temperature
Creep-resistant bolting up to about 540 °C
Nuts
Pairs with ASTM A194 Grade 4 or 7
Traceability
EN 10204 3.1 per heat; 3.2 on request
Quick Section Links
- What Is ASTM A193 Grade B16?
- B16 Round Bar vs Finished B16 Bolts
- ASTM A193 B16 Round Bar Specifications
- Equivalent Grades & Designations of ASTM A193 B16
- Mechanical Properties of ASTM A193 B16 Round Bar and Heat Treatment
- Sizes, Tolerances and Weight Chart of ASTM A193 B16 Alloy Steel B16 Round Bars
What Is ASTM A193 B16, and What Does the Specification Cover?
ASTM A193 / A193M is the standard specification for alloy-steel and stainless steel bolting used in high-temperature or high-pressure service on pressure vessels, valves, flanges and fittings. Grade B16 is its chromium-molybdenum-vanadium grade. Vanadium refines the grain and forms stable carbides, which helps the steel keep its clamping load (resist stress relaxation) and resist creep at temperatures where plain Cr-Mo grades such as B7 begin to lose strength.
A193 is a bolting specification, not a bar-stock specification. B16 round bar is supplied in the B16 grade and in a heat-treated condition so that it can be machined into studs and bolts, with chemistry and mechanical results shown on the mill test certificate. Whether a bar is accepted for a given job depends on your client’s specification, so tell us if the finished part must be bought as a finished fastener and we will quote ASTM A193 B16 bolts instead. Read the full standard overview on our ASTM A193 page.
ASTM A193 B16 Round Bar Specifications
| Item | Details |
|---|---|
| Standards | ASTM A193 / A193M, ASME SA193 |
| Round bar size | Diameter [10-200 mm] |
| Length | 1000-6000 mm random or fixed; cut to size on request |
| Finish | Black (hot rolled), peeled, rough turned, bright (cold drawn), centreless ground |
| Tolerance | h9, h10, h11 (ISO 286-2) for bright bar, or as per customer requirement |
| Condition | As-rolled, annealed, quenched and tempered to A193 B16 |
| Marking | Heat number and grade on tags / stamped on larger bars |
| Packing | Wooden cases or pallets, VCI paper or oil coat, steel strapping |
Surface finish codes
| Code | Meaning | Code | Meaning |
|---|---|---|---|
| CD | Cold drawn | P | Polished |
| BD | Bright drawn | SRE | Slit rolled edge |
| CG | Centreless ground | HF | Hot finished |
| CF | Cold finished | HRAP | Hot rolled annealed & pickled |
| P&T | Peeled and turned | RT | Rough turned / peeled |
| ST | Smooth turned | PR | Peeled and reeled |
Equivalent Grades & Designations of ASTM A193 B16
| System | Designation |
|---|---|
| ASTM | ASTM A193 / A193M Grade B16 |
| ASME | ASME SA193 Grade B16 |
| Common names | B16, B16 alloy, B16 bolt material, Cr-Mo-V bolting steel |
| Closest EN / DIN | 1.7711 / 40CrMoV4-6 |
| British Standard | BS 4882 Grade B16 |
| Matching nut | ASTM A194 Grade 4 or 7 |
| Compare with | B7 bolts, B8M bolts, A320 L7 bolts |
Chemical Composition (%) of ASTM A193 B16 Round Bars
| C | Mn | P | S | Si | Cr | Mo | V | |
|---|---|---|---|---|---|---|---|---|
| Min | 0.36 | 0.45 | – | – | 0.15 | 0.80 | 0.50 | 0.25 |
| Max | 0.47 | 0.70 | 0.035 | 0.040 | 0.35 | 1.15 | 0.65 | 0.35 |
Role of the key elements: carbon gives hardenability and strength; chromium and molybdenum give through-hardening, tempering resistance and elevated-temperature strength; vanadium forms fine carbides that raise creep and relaxation resistance. There is no nickel in B16, which is why it is not a corrosion-resistant grade.
Mechanical Properties of ASTM A193 B16 Round Bar and Heat Treatment
| Bar diameter | Tensile strength, min | Yield strength, min | Elongation, min | Reduction of area, min | Hardness, max |
|---|---|---|---|---|---|
| Up to M64 (2.5 in) | 125 ksi / 860 MPa | 105 ksi / 725 MPa | 18 % | 50 % | 321 HBW or 35 HRC |
| Over M64 to M100 (2.5-4 in) | 110 ksi / 760 MPa | 95 ksi / 655 MPa | 17 % | 45 % | 321 HBW or 35 HRC |
| Over M100 to M180 (4-7 in) | 100 ksi / 690 MPa | 85 ksi / 585 MPa | 16 % | 45 % | 321 HBW or 35 HRC |
Heat treatment: B16 is austenitised, quenched in oil and tempered. The specification sets a minimum tempering temperature of about 650 C (1,200 F). Tempering well above the service temperature is what keeps the bar stable in hot service.
Physical properties (typical, low-alloy Cr-Mo-V steel)
| Property | Value |
|---|---|
| Density | approx. 7.85 g/cm3 |
| Modulus of elasticity | approx. 205 GPa |
| Mean thermal expansion (20-100 C) | approx. 12 x 10^-6 /C |
| Thermal conductivity | approx. 40 W/m.K |
| Magnetic | Yes (ferritic / martensitic structure) |
Sizes, Tolerances and Weight Chart of ASTM A193 B16 Alloy Steel B16 Round Bars
Stock lengths 1000-6000 mm; cut-to-size available. Weight per metre = diameter in mm squared x 0.00617 (density 7.85 g/cm3).
| Dia (mm) | kg/m | 3 m (kg) | 6 m (kg) | Dia (mm) | kg/m | 3 m (kg) | 6 m (kg) |
|---|---|---|---|---|---|---|---|
| 10 | 0.62 | 1.9 | 3.7 | 50 | 15.43 | 46.3 | 92.6 |
| 12 | 0.89 | 2.7 | 5.3 | 56 | 19.35 | 58.0 | 116.1 |
| 16 | 1.58 | 4.7 | 9.5 | 64 | 25.27 | 75.8 | 151.6 |
| 20 | 2.47 | 7.4 | 14.8 | 75 | 34.71 | 104.1 | 208.2 |
| 25 | 3.86 | 11.6 | 23.1 | 80 | 39.49 | 118.5 | 236.9 |
| 30 | 5.55 | 16.7 | 33.3 | 90 | 49.98 | 149.9 | 299.9 |
| 32 | 6.32 | 19.0 | 37.9 | 100 | 61.70 | 185.1 | 370.2 |
| 36 | 8.00 | 24.0 | 48.0 | 125 | 96.41 | 289.2 | 578.4 |
| 40 | 9.87 | 29.6 | 59.2 | 150 | 138.83 | 416.5 | 833.0 |
| 45 | 12.49 | 37.5 | 75.0 | 200 | 246.80 | 740.4 | 1480.8 |
For other sizes, hex, square and flat bar, use our metal weight calculator.
Inch to millimetre reference
| Inch | 1/2 | 5/8 | 3/4 | 7/8 | 1 | 1-1/4 | 1-1/2 | 2 | 2-1/2 | 3 | 4 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| mm | 12.7 | 15.9 | 19.1 | 22.2 | 25.4 | 31.8 | 38.1 | 50.8 | 63.5 | 76.2 | 101.6 |
“Contact Jade Special Metals today with your requirement for Alloy Steel ASTM A193 B16 Round Bars and ASTM A193 B16 Rods. We assure you of the best quote.
ASTM A193 B16 Bar Forms in Stock

ASTM A193 B16 Hex Bar

ASTM A193 B16 Square Bar

ASTM A193 B16 Bright Bar

ASTM A193 B16 Threaded Bar

ASTM A193 B16 Flat Bar

ASTM A193 B16 Rectangular Bar
Machining, Threading and Fabrication Notes
- Machining: machine in the annealed or QT condition with sharp carbide tooling and flood coolant. QT bar is tough (up to 321 HBW), so use rigid set-ups and positive feeds.
- Threading: rolled threads give better fatigue life than cut threads; threads are normally cut or rolled after heat treatment on QT bar.
- Welding: B16 is not normally welded for bolting. Weld repair is outside A193; any welding needs a qualified procedure.
- Corrosion protection: B16 rusts. Oil or coat finished parts for storage, and specify a coating (for example PTFE or phosphate) for the service environment.
Applications of ASTM A193 B16 Round Bars
- Power generation: steam and gas turbine casing studs, boiler and superheater flange bolting, main steam line joints.
- Oil & gas and refineries: high-temperature flange and valve bolting, heater and reactor joints.
- Petrochemical and chemical plants: high-temperature, high-pressure joints; see our stud bolts and heavy hex bolts.
- Pressure vessels, valves and heat exchangers: bonnet and cover studs, header bolting.
- Mechanical and plant engineering: high-strength threaded rod, tie rods and fixtures running hot.
Where not to use B16: wet corrosive, marine immersion or food-contact service (use stainless, duplex or nickel alloy), and low-temperature or cryogenic service (use A320 L7). B16 is a plain low-alloy steel and needs coating or oiling against rust.
ASTM A193 B16 Round Bars Export Markets
Gulf (UAE, Saudi Arabia, Qatar, Kuwait, Oman): power, refinery and petrochemical maintenance and EPC projects specify B16 for hot flange and turbine bolting. See fasteners suppliers in UAE, Saudi Arabia, Kuwait and Oman.
Europe (Germany, Italy, France, Netherlands): supplied with EN 10204 3.1 / 3.2 documentation; see Germany, Italy, France and Netherlands.
Asia Pacific (Singapore, Malaysia, Thailand, Indonesia, Vietnam, South Korea): see Singapore, Malaysia, Thailand and Indonesia.
Related Round Bars and Guides
- Alloy Steel F22 Round Bars
- Alloy Steel F11 Round Bars
- Alloy Steel F91 Round Bars
- ASTM A182 F51 Round Bars
- Alloy Steel Round Bars
- ASTM A193 B16 Bolts
- ASTM A193 Standard Overview
Frequently Asked Questions
What is ASTM A193 B16 round bar?
Is ASTM A193 a bar specification?
What is the chemical composition of ASTM A193 B16?
What is the tensile and yield strength of A193 B16?
What is the difference between A193 B16 and B7?
What is the maximum service temperature for B16?
Which nuts are used with A193 B16 studs and bolts?
Is ASTM A193 B16 corrosion resistant?
What is the equivalent of ASTM A193 B16?
How much does a 50 mm A193 B16 round bar weigh?
Can you supply heat-treated B16 bar and cut lengths?
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