Aluminium round bar (rod) is solid cylindrical stock made by extrusion, cold drawing, forging or casting, in alloys from soft 1100 to aerospace 7075. For most machined parts the choice comes down to 6061 or 6082 for all-round use, 2011 for high-speed turning, and 2024 or 7075 when strength is the priority. This guide compares the alloys, explains how production route affects tolerance and properties, and gives the size, weight and standards information needed to order the right bar.
Buying round bar well means answering three questions in order: which alloy and temper gives the strength, machinability and corrosion resistance the part needs; which production route gives the tolerance, surface and internal soundness required; and which diameter and length minimise waste. Getting the first decision wrong is costly, while the other two mainly affect price and machining time.
Round bar is the most widely used aluminium stock in machine shops. CNC turning centres and Swiss-type lathes feed it continuously; milling shops saw it into blanks for flanges, hubs and pistons; fabricators use it for shafts, pins, handrails and fixings. Because the part is usually machined, the bar’s alloy controls tool life, chip form and surface finish as much as the final strength.
This guide is written for engineers and buyers comparing options. For a concise product specification of round bar, including size range and stock forms, see the round bar specification page; for individual alloys, follow the links in the related section.
The table gives typical room-temperature properties for the main bar alloys. Typical values are what the material usually achieves; for design, use the specified minimums of the ordering standard, which are lower and vary with diameter.
| Alloy and temper | Typical tensile strength | Typical yield strength | Elongation | Machinability | Corrosion resistance |
|---|---|---|---|---|---|
| 1100-H14 | 125 MPa | 115 MPa | 9 – 20 % | Poor (gummy) | Excellent |
| 3003-H14 | 150 MPa | 145 MPa | 8 – 16 % | Poor | Excellent |
| 5083-O / H111 | 290 MPa | 145 MPa | 22 % | Fair | Excellent, including seawater |
| 6063-T6 | 241 MPa | 214 MPa | 12 % | Fair | Very good |
| 6061-T6 | 310 MPa | 276 MPa | 12 – 17 % | Good | Very good |
| 6082-T6 (EN 755-2 minimum, Ø20 – 150 mm) | 310 MPa min | 260 MPa min | 8 % min | Good | Very good |
| 2011-T3 | 379 MPa | 296 MPa | 15 % | Excellent (free-cutting) | Poor; protect or anodise |
| 2017-T4 | 427 MPa | 276 MPa | 22 % | Good | Fair |
| 2024-T4 / T351 | 469 MPa | 324 MPa | 19 – 20 % | Good | Fair to poor |
| 2014-T6 | 483 MPa | 414 MPa | 13 % | Good | Fair to poor |
| 7075-T6 | 572 MPa | 503 MPa | 11 % | Very good | Fair |
Typical values from Aluminum Association and ASM International data, except 6082 which shows EN 755-2 minimums. Actual results are reported on each lot’s mill test certificate.
6061, 6082, 6005 and 6063 combine moderate to good strength with weldability, anodising response and corrosion resistance. They are the default for brackets, shafts, fixtures, manifolds and structural pins. 6061 dominates ASTM markets and 6082 European ones.
2011, 2007 and 6262 contain elements that break chips into short pieces, so automatic lathes run fast without chip tangling. Traditional grades contain lead or bismuth; check the chemistry where RoHS or end-of-life rules apply.
2024, 2014 and 2017 offer high strength and good fatigue performance for aircraft fittings, fasteners and highly stressed machine parts. Copper content lowers corrosion resistance, so parts are usually anodised or painted.
7075 is the strongest common bar alloy and machines to a fine finish. T73 tempers trade some strength for much better stress-corrosion resistance. 7050 is used for thick, highly loaded aerospace parts.
5083, 5086 and 5052 resist seawater and keep their strength after welding because they are not heat-treated. Strength comes from magnesium content and cold work.
2618 and 2219 keep useful strength at elevated temperature; 4032 has low thermal expansion and good wear resistance for forged pistons; 1100 and 6101 serve electrical uses.
| Type | How it is made | Typical diameter range | Strengths | Governing standards |
|---|---|---|---|---|
| Extruded | Hot billet forced through a round die, then quenched, stretched and aged | about Ø5 – 300 mm, larger on big presses | Widest alloy and size choice, economical, good straightness in stretched tempers | ASTM B221, EN 755-2/-3, AMS-QQ-A-200 |
| Cold-finished (drawn, turned or ground) | Extruded bar drawn through a die or turned and ground to size | Drawn mainly in small and medium sizes; turned or ground bar larger | Tight diameter tolerance, bright surface, good roundness for automatic lathes | ASTM B211, EN 754-2/-3, AMS-QQ-A-225 |
| Forged | Billet hot-worked by open-die forging or rolling, then heat-treated | Large diameters, beyond extrusion range | Refined, sound grain structure through thick sections; preferred for critical large parts | ASTM B247, EN 586, AMS specifications |
| Cast (continuous or DC cast log) | Direct-chill cast log, homogenised and machined | Large diameters | Low cost per kilo for large blanks; isotropic properties but lower ductility than wrought | Supplier specification |
A useful rule: if the bar surface stays on the finished part, as in a shaft running in a bush or a pin in a reamed hole, choose cold-finished bar. If everything will be machined away, extruded bar is cheaper. For diameters beyond what local presses can extrude, or for fatigue-critical parts thicker than about 150 mm, ask for forged bar. Related guides: free-cutting bar, precision ground bar and large-diameter bar.
Metric bar is commonly stocked in 2.5 m, 3 m and 6 m lengths, inch bar in 12 ft lengths; cut pieces and blanks are supplied to order. The table gives weights for popular diameters at a density of 2.70 g/cm³ (6xxx alloys). Multiply by about 1.03 for 2011 and 2024 and by 1.04 for 7075.
| Diameter (mm) | kg per metre | kg per 3 m bar | kg per 6 m bar |
|---|---|---|---|
| 6 | 0.076 | 0.23 | 0.46 |
| 8 | 0.136 | 0.41 | 0.81 |
| 10 | 0.212 | 0.64 | 1.27 |
| 12 | 0.305 | 0.92 | 1.83 |
| 16 | 0.543 | 1.63 | 3.26 |
| 20 | 0.848 | 2.54 | 5.09 |
| 25 | 1.325 | 3.98 | 7.95 |
| 30 | 1.909 | 5.73 | 11.45 |
| 40 | 3.393 | 10.18 | 20.36 |
| 50 | 5.301 | 15.90 | 31.81 |
| 60 | 7.634 | 22.90 | 45.80 |
| 80 | 13.572 | 40.72 | 81.43 |
| 100 | 21.206 | 63.62 | 127.24 |
| 120 | 30.537 | 91.61 | 183.22 |
| 150 | 47.713 | 143.14 | 286.28 |
| 200 | 84.824 | 254.47 | 508.94 |
| 250 | 132.537 | 397.61 | 795.22 |
| 300 | 190.854 | 572.56 | 1145.12 |
Inch diameters such as 1/2, 3/4, 1, 1-1/2 and 2 in are widely available to ASTM B211 and B221. A full metric and inch size chart with weights is in our round bar die size chart, and the bar weight calculator works out any size.
| Standard | Covers | Notes |
|---|---|---|
| ASTM B221 | Extruded bar, rod, wire, profiles and tube | Most common US specification for extruded rod |
| ASTM B211 | Rolled or cold-finished bar, rod and wire | Tighter tolerances; free-machining alloys |
| ASTM B247 | Die and hand forgings | For forged bar and rolled rings |
| AMS-QQ-A-200 / AMS-QQ-A-225 | Aerospace extruded and cold-finished bar, by alloy slash sheet | Replaced the cancelled federal QQ-A-200 and QQ-A-225; for example /8 for 6061 and /11 or /9 for 7075 |
| EN 755-2 / EN 755-3 | Extruded bar mechanical properties / round bar tolerances | European standard for extruded rod |
| EN 754-2 / EN 754-3 | Cold-drawn bar mechanical properties / round bar tolerances | European standard for drawn rod |
| EN 573-3 | Chemical composition of wrought alloys | Applies to all EN orders |
| JIS H4040 | Aluminium bar and rod (Japan) | Designations such as A6061BE (extruded) and A6061BD (drawn) |
When a drawing names a specification, order to it rather than to a "similar" grade; the certificate must show the right standard for the part to pass incoming inspection. Where only an alloy is named, state whether ASTM or EN tolerances apply, because metric and inch tolerance tables differ.
| Application | Usual alloy and temper | Reason |
|---|---|---|
| Hydraulic and pneumatic fittings, manifolds | 6061-T6511, 6082-T6, 2011-T3 | Clean machining of ports and threads; 2011 for high-volume turned fittings |
| Shafts, rollers and spindles | 6061-T6, 6082-T6, 7075-T6 for high load | Stiffness-to-weight and straightness in stretched tempers |
| Aircraft fittings and fasteners | 2024-T351, 2014-T6, 7075-T73 | High strength and fatigue resistance; T73 for stress-corrosion resistance |
| Automatic-lathe parts (screws, nuts, inserts) | 2011-T3, 6262-T9, 2007 | Short chips and long tool life at high spindle speeds |
| Marine pins, bollards and fittings | 5083-H112, 5086, 6082-T6 anodised | Seawater resistance and weldability |
| Forged pistons and wear parts | 4032-T6, 2618-T61 | Low expansion and strength at temperature |
| Handrails, furniture and decorative turned parts | 6063-T6, 6060 | Bright anodised finish and good surface |
| Electrical connectors and conductor rod | 6101-T6, 1350, 1100 | High electrical conductivity |
These pairings are starting points. Loads, temperature, corrosive environment and the finishing process can change the best choice, so share the operating conditions with your supplier when the part is critical. A quick comparison of the two most requested CNC grades is in our article on 6061 vs 7075 for CNC machining.
6061-T6 (or T6511) worldwide, and 6082-T6 in Europe. Both give a good balance of strength, machinability, weldability and corrosion resistance at moderate cost.
Among common grades, 7075-T6 has the highest strength, with typical tensile strength around 570 MPa, followed by 2014-T6 and 2024. For thick, highly loaded aerospace parts 7050 is also used.
2011-T3 is the classic free-cutting grade and produces short chips at high speed. 6262 is an alternative with better corrosion resistance. 6061 and 7075 also machine well but give longer chips on lathes.
Extruded bar is hot-formed through a die and is the economical choice for parts that will be fully machined. Cold-finished bar is drawn, turned or ground after extrusion for tighter diameter tolerance, better roundness and a bright surface.
Weight in kg per metre equals diameter in mm squared × 0.0021206 for 6xxx alloys. A Ø50 mm bar weighs about 5.30 kg/m. Multiply by about 1.04 for 7075.
6061, 6082, 6063 and the 5xxx alloys weld readily by TIG or MIG. 2011, 2024 and 7075 are generally unsuitable for structural fusion welding.
Tell us the alloy, temper, diameter, length and quantity. We will confirm the best bar type, certification and a delivered price.
