Steel A36 · finish state
Steel A36-HDG
Properties of the HDG condition, compared with the other A36 tempers.
Pick when the part sees outdoor or damp service and painting maintenance is undesirable; zinc coating gives sacrificial protection but restricts welding and fine tolerances.
What is A36-HDG?
A36-HDG is A36 supplied in the HDG condition — pick when the part sees outdoor or damp service and painting maintenance is undesirable; zinc coating gives sacrificial protection but restricts welding and fine tolerances. A36-HDG has a yield strength of 260 MPa (37.7 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 92% of steel grades. Elongation at break is 21% and the elastic modulus is 200 GPa (29 Msi). A36-HDG has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,470°C (2,678 °F). HR is the default condition FabDigit quotes; HDG is available on request or by drawing note.
Advantages
- High electrical conductivity — 11 % IACS, better than 98% of steel grades
- Good corrosion resistance — 45/100, better than 98% of steel grades
- Conducts heat well — 51.9 W/m·K (30 BTU/hr·ft·°F), better than 96% of steel grades
- Forms and bends easily — 80/100, better than 92% of steel grades
- Easy to machine — 60/100, better than 83% of steel grades
Limitations
- Hard to polish — 40/100, worse than 96% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Low strength — 260 MPa (37.7 ksi), worse than 92% of steel grades
A36-HDG properties
Typical room-temperature values for A36-HDG — 8 properties are specific to this condition; the rest are grade-level values shared by every A36 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
A36-HDG has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,470°C (2,678 °F).
Mechanical16
A36-HDG has a yield strength of 260 MPa (37.7 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 92% of steel grades. Elongation at break is 21% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
A36-HDG is rated for continuous service to 200°C (392 °F). It conducts heat at 51.9 W/m·K (30 BTU/hr·ft·°F), better than 96% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
A36-HDG conducts electricity at 11 % IACS, better than 98% of steel grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), better than 98% of steel grades.
Sustainability4
Producing a kilogram of A36-HDG takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 40%.
Manufacturability7
A36-HDG's machinability is good (60/100, better than 83% of steel grades); weldability good (55/100); formability very good (80/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other A36 tempers and conditions
A36 is also supplied in 5 other conditions. The full side-by-side table is on the A36 overview.
- HRDefaultDefault stock condition for plate, structural shapes and merchant bar; cheapest and most weldable, with mill scale and loose dimensional tolerance.260 MPa yield · 120 HB
- CDChoose for round/square/flat bar where a bright straight surface, tight size tolerance and higher yield are wanted for shafts and machined parts.415 MPa yield · 155 HB
- CRPick for thin sheet needing a clean scale-free surface, tight thickness tolerance and higher yield, at the cost of ductility and springback.380 MPa yield · 150 HB
- NormalizedSpecify for thick plate or weldments needing uniform grain, better notch toughness and reduced property scatter versus as-rolled.290 MPa yield · 130 HB
- HDGPick when the part sees outdoor or damp service and painting maintenance is undesirable; zinc coating gives sacrificial protection but restricts welding and fine tolerances.260 MPa yield · 120 HB
- AnnealedUse when maximum ductility and low residual stress are needed for deep forming, severe bending or stability after heavy machining.230 MPa yield · 112 HB
Working with A36-HDG
Is A36 easy to machine?
Cuts easily but gummy — use positive-rake tooling, coolant and moderate speeds; hot-rolled scale is abrasive so break it with a first roughing pass.
Can A36 be welded?
Prequalified for all common processes (SMAW/GMAW/FCAW/SAW) with E70XX-class filler; preheat only for thick sections or restrained joints per AWS D1.1.
Can A36 be formed, bent or molded?
Excellent cold bending, punching and roll forming; keep bend lines transverse to rolling direction and allow generous inside radii on thick as-rolled plate.
What surface finishes work on A36?
No natural corrosion resistance — shot blast to SA 2.5 then paint, hot-dip galvanize, zinc plate, phosphate or black oxide; polishes only to a dull finish and will rust unprotected.
A36 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C0.25 max for plate ≤20 mm; 0.26 max for shapes | ≤ 0.26 | 0.2 |
| Mnrequired for plate over 20 mm; not specified for shapes ≤634 N/m | 0.6 – 1.2 | 0.9 |
| Si0.40 max for plate; 0.15–0.40 for heavier plate | 0.15 – 0.4 | 0.25 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.05 | 0.03 |
| Cuonly when copper steel is specified | ≥ 0.2 | 0.25 |
| Fe | balance | — |
A36-HDG — frequently asked
What is A36-HDG used for?
A36-HDG is typically used for welded structural frames, base plates and gussets, machine bases and heavy weldments, brackets and mounting plates, bridge components and handrails, stairs and ladders. In short: cheapest structural steel.
What is the yield strength of A36-HDG?
A36-HDG has a typical yield strength of 260 MPa (37.7 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 92% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is A36-HDG easy to machine?
Reasonably — machinability is rated good (60/100, better than 83% of steel grades). Cuts easily but gummy — use positive-rake tooling, coolant and moderate speeds; hot-rolled scale is abrasive so break it with a first roughing pass.
Can A36-HDG be welded?
Yes — weldability is rated good (55/100). Prequalified for all common processes (SMAW/GMAW/FCAW/SAW) with E70XX-class filler; preheat only for thick sections or restrained joints per AWS D1.1.
What surface finishes work on A36-HDG?
No natural corrosion resistance — shot blast to SA 2.5 then paint, hot-dip galvanize, zinc plate, phosphate or black oxide; polishes only to a dull finish and will rust unprotected.
Can A36-HDG be formed, bent or molded?
Excellent cold bending, punching and roll forming; keep bend lines transverse to rolling direction and allow generous inside radii on thick as-rolled plate.
What is the maximum service temperature of A36-HDG?
A36-HDG is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between A36-HR and A36-CD?
HR is the default condition — default stock condition for plate, structural shapes and merchant bar; cheapest and most weldable, with mill scale and loose dimensional tolerance. CD: choose for round/square/flat bar where a bright straight surface, tight size tolerance and higher yield are wanted for shafts and machined parts. Yield strength is 260 MPa in HR versus 415 MPa in CD.
Can FabDigit make parts in A36-HDG?
Yes — A36-HDG is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A36/A36M Standard Specification for Carbon Structural Steel — ASTM International (2019)
- GB/T 700 Carbon structural steels (Q235B) — SAC (2006)
- EN 10025-2 Hot rolled structural steels (S235JR/S275JR) — CEN (2019)
- ASM Handbook Vol.1 Properties and Selection: Irons, Steels — ASM International (1990)
- Steel Construction Manual, 15th ed. — AISC (2017)
- Machinery's Handbook, 30th ed. — Industrial Press (2016)
- AWS D1.1/D1.1M Structural Welding Code — Steel — AWS (2020)
- worldsteel LCI data for steel products — World Steel Association (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.