ASTM A105 / SA 105 Round Bar, Hot Rolled & Forged Carbon Steel Bar Stock Manufacturer in India
ASTM A105 round bar is carbon steel bar made to the ASTM A105 / ASME SA105 (UNS K03504) grade, the standard material for forged flanges, fittings and valve parts in ambient and high-temperature piping systems. It is a carbon-manganese steel with 0.35% maximum carbon, a minimum tensile strength of 485 MPa and a minimum yield strength of 250 MPa, and it is the base material for ASME B16.5 flange group 1.1. Jade Alloys stocks A105 round bars in hot rolled (black), forged, peeled and bright finishes. Bars ship ex-stock from Mumbai with EN 10204 3.1 mill test certificates and are exported worldwide.
What is ASTM A105 Carbon Steel Round Bar?
ASTM A105 is a specification for carbon steel forgings used in piping components for ambient and higher-temperature pressure systems, including forgings made to dimensional standards such as ASME B16.5 and B16.11, up to 4,540 kg (10,000 lb). Round bar is not a separate product form in that specification. Bar is supplied in the A105 grade, as hot rolled or forged bar, with chemistry and mechanical results shown on the MTC. Many fabricators machine blind flanges, couplings, plugs and small valve parts from this bar. Whether a bar is accepted for a given job depends on your client’s specification, so tell us if the finished part must come from a forging and we will quote the forged bar.
Hot rolled vs forged vs bright A105 bar
| Supply condition | What it is | Best for | Note |
|---|---|---|---|
| Hot rolled (black) | Rolled from billet, scaled surface | General turning stock, plugs, couplings, fittings | Most economical; allow machining stock for the scale and ovality |
| Forged bar | Open-die forged, refined grain structure | Larger diameters and jobs that call for forged material | Higher cost; confirm size range |
| Bright / peeled / ground | Cold drawn, peeled or ground to size | Small parts, closer tolerance, less machining | Check hardness against the 187 HBW maximum |
| Normalised (A105N) | Heat treated for uniform grain | Orders that specify the N condition | State it on the purchase order |
Where A105 bar is used
A105 bar is machined into blind flanges, slip-on and threaded flanges, couplings, bosses, stubs and valve bodies, bonnets and trims for oil and gas, refinery, petrochemical, chemical and power plants. Heat exchanger fabricators also turn tube plugs and SA 105 header plugs from this bar. See the reference page on ASTM A105 specifications for flange and fitting standards.
A105 is used in pressure piping from ambient up to elevated temperatures, within the limits of the governing code, for example ASME B31.3 or the B16.5 pressure-temperature ratings. It is a plain carbon steel, so it needs protection from rust and is not a corrosion-resistant alloy. Choose a different grade when the duty changes:
- Low temperature or impact requirements: ASTM A350 LF2 round bars
- Higher temperature creep service: Cr-Mo grades such as alloy steel F22 round bars
- Corrosive media or seawater: stainless steel round bars or duplex steel round bars
Quick Section Links
- ASTM A105 Round Bar at a Glance
- ASTM A105 Round Bar Specifications
- Surface finish codes
- Equivalent Grades & Designations of ASTM A105 Round Bars
- Chemical Composition of ASTM A105 (%)
- Mechanical & Physical Properties of ASTM A105 Round Bars
- ASTM A105 Round Bar Weight Chart
- Applications of ASTM A105 Round Bars
- Frequently Asked Questions
ASTM A105 Round Bar at a Glance
| Common names | ASTM A105, ASME SA105, SA 105, A105 CS, carbon steel A105 bar |
|---|---|
| UNS | K03504 |
| Specification | ASTM A105 / A105M; ASME SA105 (BPVC Section II-A) |
| Material type | Carbon-manganese steel, forging grade |
| Lengths | 1000 – 6000 mm, or cut to size |
| Supply condition | Hot rolled, forged, cold drawn (bright) |
| Minimum tensile strength | 485 MPa (70 ksi) |
| Minimum yield strength | 250 MPa (36 ksi) |
| Certification | Mill Test Certificate EN 10204 3.1 |
| Supply | Ex-stock Mumbai; worldwide export |
ASTM A105 Round Bar Specifications
| Item | Details |
|---|---|
| Standards | ASTM, ASME, EN, DIN, BS, IS, JIS |
| Specification | ASTM A105 / ASME SA105 |
| Threaded bar | See our threaded rod weight chart |
| Length | 1000 – 6000 mm random or fixed; cut to size on request |
| Finish | Black (hot rolled), bright (cold drawn), peeled, rough turned, polished, forged |
| Tolerance | As per customer requirement |
| Forms | Round, rod, hex, square, flat, rectangular, hollow, threaded, half-round, triangle, forged bar, rings, blocks |
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 A105 Round Bars
| System | Designation |
|---|---|
| Trade names | Invar 36®, Alloy 36, Nilo 36, FeNi36 |
| UNS | K93600, K93603 |
| Werkstoff Nr. | 1.3912 |
| ASTM | ASTM F1684 |
| DIN | DIN 17745 – Ni36 |
| China (GB) | 4J36 |
Chemical Composition of ASTM A105 (%)
| C | Mn | P | S | Si | Ni | Cr | Fe | Co | |||
|---|---|---|---|---|---|---|---|---|---|---|---|
| C | Mn | P | S | Si | Cu | Ni | Cr | Mo | V | Nb | |
| 0.35 max | 0.60-1.05 | 0.035 max | 0.040 max | 0.10-0.35 | 0.40 max | 0.40 max | 0.30 max | 0.12 max | 0.05 max | 0.02 max |
Residual limits: Cu+Ni+Cr+Mo+V 1.00% max; Cr+Mo 0.32% max.
Mechanical & Physical Properties of ASTM A105 Round Bars
| Property | Typical value |
|---|---|
| Tensile strength | 485 MPa (70 ksi) min |
| Yield strength | 250 MPa (36 ksi) min |
| Elongation | 22% min |
| Hardness | 187 HBW max |
| Density | approx. 7.85 g/cm3 (one competitor lists 8.08, which is wrong for carbon steel) |
| Modulus of elasticity | approx. 200 GPa |
Typical values; actual results are on the MTC for each heat.
ASTM A105 Round Bar Weight Chart
Weight per metre of round bar (kg/m) = D x D x 0.00617, where D is diameter in mm. Need a cut length or a different shape? Use our metal weight calculator.
| Diameter (mm) | Weight (kg/m) | Diameter (mm) | Weight (kg/m) |
|---|---|---|---|
| 10 | 0.62 | 50 | 15.4 |
| 20 | 2.47 | 75 | 34.7 |
| 25 | 3.86 | 100 | 61.7 |
| 32 | 6.32 | 150 | 138.8 |
| 40 | 9.87 | 200 | 246.8 |
Applications of ASTM A105 Round Bars
- Oil & gas and refineries: machined flanges, blind flanges, valve bodies and bonnets
- Petrochemical and chemical plants: couplings, fittings, instrument parts
- Power generation: boiler and steam-line components, header plugs
- Heat exchangers: tube plugs and shoulder plugs machined from bar
- Pipeline and plant engineering: stubs, nipples, spools and supports
- General mechanical engineering: shafts, pins, bushes and fixtures
A105 is a plain carbon steel with limited corrosion resistance. Where corrosion is the main concern, consider stainless steel round bars.
Machining & Fabrication Tips
- A105 machines well, similar to other low-alloy forging steels. Use sharp carbide tooling and normal coolant.
- It is weldable with qualified procedures; preheat and post-weld heat treatment depend on section thickness and the governing code.
- Oil, paint or coat finished parts to prevent rust during storage.
Quality, Testing & Certification
Each lot is supplied with a Mill Test Certificate (EN 10204 3.1) showing heat number, chemical analysis and mechanical results. Export packing in bundles, wooden cases or pallets with poly wrap. See our Quality and Certificate pages.
Related ASTM A105 Carbon Steel Round Bars
Frequently Asked Questions
ASTM A105 round bar is solid carbon steel bar supplied to the ASTM A105 / ASME SA105 (UNS K03504) chemistry used for forged piping components. It is machined into flanges, fittings and valve parts for ambient and high-temperature pressure service.
ASTM A105 is a specification for carbon steel forgings. Round bar is supplied in A105 grade and chemistry, as hot rolled or forged bar, with test certificates confirming chemistry and mechanical properties. Confirm the required condition on your purchase order.
Maximum 0.35% carbon, 0.60-1.05% manganese, 0.10-0.35% silicon, 0.035% phosphorus and 0.040% sulphur, with residual limits on Cu, Ni, Cr, Mo, V and Nb. See the chemical composition table above.
Minimum 485 MPa (70 ksi) tensile and 250 MPa (36 ksi) yield, with 22% minimum elongation and 187 HBW maximum hardness.
A105 is the base grade for ambient and high-temperature service. A105N is supplied normalised. A350 LF2 is impact tested for low-temperature service.
Weight in kg per metre equals diameter in mm squared times 0.00617. A 50 mm bar weighs about 15.4 kg/m.
No. It is a plain carbon steel and rusts in humid or marine air unless oiled, painted or coated. Use stainless or duplex bars where corrosion resistance is needed.
Round bar in lengths of 1000 mm to 6000 mm or cut to size, with EN 10204 3.1 mill test certificates, packed for export.
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