ASTM A36 Structural Carbon Steel
The structural steel: 36 ksi yield, 58 to 80 ksi tensile, weldable and available in every shape — for anchor bolts, stay rods, U-bolts, plates and brackets made from bar and plate.
What A36 is.
ASTM A36 is the standard carbon steel for structural shapes, plates and bars. It is specified by mechanical properties, 36 ksi minimum yield and 58 to 80 ksi tensile, with chemistry limits that keep it weldable in any thickness. For fasteners it is the base material for anchor bolts, stay rods, U-bolts and threaded rod on waterworks and structural jobs, usually hot-dip galvanized.
We machine and thread A36 bar into stay rods, anchor bolts, U-bolts and brackets, and supply plate parts cut and drilled, with galvanizing or painting as the job requires.
Chemical composition.
| Element | Symbol | Min % | Max % |
|---|---|---|---|
| Carbon (bars ≤¾ in.) | C | — | 0.26 |
| Carbon (bars over ¾ to 1½ in.) | C | — | 0.27 |
| Carbon (bars over 1½ to 4 in.) | C | — | 0.28 |
| Carbon (bars over 4 in.) | C | — | 0.29 |
| Manganese (bars over ¾ in.) | Mn | 0.60 | 0.90 |
| Phosphorus | P | — | 0.04 |
| Sulfur | S | — | 0.05 |
| Silicon | Si | — | 0.40 |
Values per ASTM A36/A36M-19 Table 3 for bars (verified against the specification). Manganese is required only for bars over ¾ in.; for each 0.01 % carbon below the maximum, manganese may rise 0.06 % to 1.35 % max (footnote B); copper 0.20 % min when copper steel is specified.
Mechanical properties.
| Condition and nominal diameter (in.) | Tensile strength, min (ksi) | Yield point, min (ksi) | Elongation, min (%) | Reduction of area, min (%) | Hardness |
|---|---|---|---|---|---|
| Bars and plates to 8 in. thick | 58 (80 max) | 36 | 23 in 2 in. · 20 in 8 in. | — | — |
| Plates over 8 in. thick | 58 (80 max) | 32 | 23 in 2 in. (less 2 points over 24 in. wide) | — | — |
Values per ASTM A36/A36M-19 Table 2 (verified against the specification). A36 specifies a yield point, not a 0.2 % offset yield strength.
Specifications that apply.
How A36 ships from Houston.
- Machined components from certified bar
- Studs, threaded rod and U-bolts
- Hex bolts and cap screws
- Nuts, washers and spacers
- Pins, shafts and bushings
A36 fasteners we make.
Every item is manufactured to your drawing or standard in A36, imperial or metric, with an EN 10204 3.1 certificate.
What is A36 steel?
A36 is defined by what it does rather than exactly what is in it: a 36 ksi minimum yield, 58 to 80 ksi tensile, and enough ductility to bend and weld without cracking. The chemistry table simply keeps carbon low enough for that. It is the base material of most buildings and bridges and, in bar form, of the anchor bolts, stay rods and U-bolts that tie equipment to them. Where a fastener specification is required, ASTM F1554 Grade 36 and A307 cover bolts of this strength.
Testing, certification and marking
- Mill test report with yield, tensile and chemistry for every heat
- Manufacturer's identification on threaded products where size allows
- EN 10204 3.1 certificate on request
- Galvanizing thickness reported when the finish is specified
1018 Carbon Steel (UNS G10180)
The everyday machining steel: low carbon, easily welded and case hardened, cold drawn for a clean finish — for pins, spacers, brackets and non-critical machined parts.
ASTM A108 cold-finished bar · chemistry per ASTM A29 / SAE J4031045 Carbon Steel (UNS G10450)
The medium-carbon workhorse: hardenable by quench and temper, induction hardenable at the surface, strong as drawn — for shafts, axles, studs, gears and hydraulic components.
ASTM A322 bar · ASTM A434 Q&T barAISI 4140 Alloy Steel (UNS G41400)
The workhorse Cr-Mo steel behind B7, L7 and Grade 7 — the bar stock for studs, shafts, couplings and any part that needs 100 to 150 ksi and good toughness.