Material Standard
ASTM A276 Download
ASTM A276/A276M is the ASTM International specification for stainless steel bars and shapes intended for general engineering applications where corrosion resistance is required. It covers hot-rolled, hot-rolled and descaled, and cold-finished bars in austenitic, ferritic, martensitic, and precipitation-hardening grades. HT PIPE stocks and supplies A276 bars in all standard grades with Mill Test Certificates per EN 10204 3.1.
ASTM A276 covers stainless steel bars and shapes in the following product forms and finishes:
| Form | Typical Sizes | Surface Finish |
|---|---|---|
| Hot-Rolled Bar | 13–305 mm diameter (rounds) | Black oxide, as-rolled surface |
| Hot-Rolled & Descaled (HRD) | 13–305 mm diameter | Pickled, descaled for better surface |
| Cold-Drawn Bar (CD) | 2.5–100 mm diameter | Bright, smooth; tight dimensional tolerances |
| Turned & Polished (T&P) | All sizes | Ground and polished; high surface quality |
| Designation | Issuing Body | Unit System | Latest Edition |
|---|---|---|---|
| ASTM A276 | ASTM International | Inch-Pound | A276-17 |
| ASTM A276M | ASTM International | SI (Metric) | A276M-17 |
| Grade | UNS No. | Key Feature | Typical Use |
|---|---|---|---|
| 302 | S30200 | 18Cr-8Ni; higher C for strength | Springs, fasteners, wire forms |
| 303 | S30300 | Free-machining; S 0.15% min | Automatic screw machine parts |
| 304 / 304L | S30400 / S30403 | 18Cr-8Ni; standard austenitic | Machined parts, shafts, food equipment |
| 309S / 310S | S30908 / S31008 | Heat-resisting; 22–25Cr | Furnace parts, heat treatment fixtures |
| 316 / 316L | S31600 / S31603 | 16Cr-10Ni-2Mo; corrosion resistant | Marine, chemical, medical, pharma |
| 321 / 347 | S32100 / S34700 | Ti / Nb stabilized; high-temp | Exhaust, turbine, aerospace |
| Grade | UNS No. | Type | Typical Use |
|---|---|---|---|
| 410 | S41000 | Martensitic | Turbines, valve stems, fasteners |
| 416 / 416Se | S41600 / S41623 | Martensitic (free-mach.) | Automatic screw machine parts |
| 420 | S42000 | Martensitic (high-C) | Cutlery, surgical instruments |
| 440A / 440C | S44002 / S44004 | Martensitic (tool steel) | Bearings, surgical tools, gauges |
| 430 / 430F | S43000 / S43020 | Ferritic / Free-mach. | Decorative, nitric acid, mach. parts |
| 446 | S44600 | Ferritic (high-Cr) | High-temp oxidation resistance |
| Grade | UNS No. | Condition | Typical Use |
|---|---|---|---|
| 630 / 17-4PH | S17400 | H900/H1000/H1100/H1150 | Aerospace, nuclear, valve parts |
| 631 / 17-7PH | S17700 | TH1050/RH950/CH900 | Springs, aerospace structures |
Note: A276 does not include duplex or super-duplex grades. Duplex bars (2205, 2507) for pressure vessels use ASTM A479.
Values are maximum unless shown as a range. Product analysis tolerances per ASTM A480/A480M.
| Grade | C % | Mn % | Si % | P % | S % | Cr % | Ni % | Mo % | Other |
|---|---|---|---|---|---|---|---|---|---|
| 302 | 0.15 | 2.00 | 0.75 | 0.045 | 0.030 | 17.0–19.0 | 8.0–10.0 | — | — |
| 303 | 0.15 | 2.00 | 1.00 | 0.20 | 0.15 min | 17.0–19.0 | 8.0–10.0 | 0.60 | — |
| 304 | 0.07 | 2.00 | 0.75 | 0.045 | 0.030 | 17.5–19.0 | 8.0–10.5 | — | — |
| 304L | 0.030 | 2.00 | 0.75 | 0.045 | 0.030 | 17.5–19.0 | 8.0–12.0 | — | — |
| 316 | 0.07 | 2.00 | 0.75 | 0.045 | 0.030 | 16.0–18.0 | 10.0–14.0 | 2.0–3.0 | — |
| 316L | 0.030 | 2.00 | 0.75 | 0.045 | 0.030 | 16.0–18.0 | 10.0–14.0 | 2.0–3.0 | — |
| 410 | 0.15 | 1.00 | 1.00 | 0.040 | 0.030 | 11.5–13.5 | 0.75 | — | — |
| 416 | 0.15 | 1.25 | 1.00 | 0.060 | 0.15 min | 12.0–14.0 | — | 0.60 | — |
| 420 | 0.15 min | 1.00 | 1.00 | 0.040 | 0.030 | 12.0–14.0 | — | — | — |
| 440C | 0.95–1.20 | 1.00 | 1.00 | 0.040 | 0.030 | 16.0–18.0 | — | 0.75 | — |
| 430 | 0.12 | 1.00 | 1.00 | 0.040 | 0.030 | 16.0–18.0 | 0.75 | — | — |
Note: Precipitation-hardening grades (630/17-4PH, 631/17-7PH) have complex compositions including Cu, Al, Ti. Full tables in ASTM A276-17. Free-machining grades 303/416/430F have elevated S (0.15–0.35%) for improved machinability.
| Grade | UNS | Tensile Strength min MPa (ksi) |
Yield Strength 0.2% min MPa (ksi) |
Elongation min % |
Hardness max |
|---|---|---|---|---|---|
| 302 | S30200 | 515 (75) | 205 (30) | 40 | 201 HB / 92 HRB |
| 303 | S30300 | 515 (75) | 205 (30) | 30 | 201 HB / 92 HRB |
| 304 | S30400 | 515 (75) | 205 (30) | 40 | 201 HB / 92 HRB |
| 304L | S30403 | 485 (70) | 170 (25) | 40 | 201 HB / 92 HRB |
| 316 | S31600 | 515 (75) | 205 (30) | 40 | 217 HB / 95 HRB |
| 316L | S31603 | 485 (70) | 170 (25) | 40 | 217 HB / 95 HRB |
| 321 | S32100 | 515 (75) | 205 (30) | 40 | 217 HB / 95 HRB |
| 347 | S34700 | 515 (75) | 205 (30) | 40 | 217 HB / 95 HRB |
| 410 | S41000 | 450 (65) | 205 (30) | 20 | 217 HB / 96 HRB |
| 416 | S41600 | 450 (65) | 205 (30) | 20 | 223 HB |
| 420 | S42000 | 650 (95) | — | 12 | 241 HB |
| 430 | S43000 | 450 (65) | 205 (30) | 22 | 183 HB / 89 HRB |
Note: For cold-drawn bars, tensile and yield strengths are typically higher than annealed values. Precipitation-hardening grades (17-4PH, 17-7PH) achieve much higher strengths after aging heat treatment. Values shown are for hot-finished or annealed condition.
| Grade Family | Required Condition | Heat Treatment | Cooling |
|---|---|---|---|
| Austenitic (304, 316…) | Annealed (unless CD) | 1010–1120°C (1850–2050°F) | Rapid quench |
| Ferritic (430, 446…) | Annealed | 760–900°C (1400–1650°F) | Air cool |
| Martensitic (410, 416…) | Annealed (default) | 750–900°C (1380–1650°F) | Furnace cool or air |
| Martensitic (hardened) | Hardened & Tempered | Harden: 925–1010°C; Temper: per type | Oil quench; subsequent temper |
| Precipitation-Hard. (17-4PH) | H900/H1000/H1100/H1150 | Sol. Anneal: 1040°C; Age: 480–620°C | Water quench; air cool after aging |
| Test | Requirement | Reference |
|---|---|---|
| Chemical Analysis (Heat) | One per heat; all elements per grade table | ASTM A276 Table 1 |
| Tensile Test | One per lot; longitudinal bar specimen | ASTM A370 |
| Hardness Test | One per lot; Brinell or Rockwell | ASTM E10 / E18 |
| Bend Test | Supplementary — thin sections | ASTM A370 |
| Intergranular Corrosion | Supplementary — "L" grades | ASTM A262 Practice A or E |
| Product | Size Range | Tolerance Standard | Typical Length |
|---|---|---|---|
| Hot-Rolled Round Bar | 13–305 mm dia. | ASTM A484/A484M | 3–6 m random |
| Cold-Drawn Round Bar | 2.5–100 mm dia. | ASTM A484/A484M (CD) | 3–6 m / exact length |
| Square & Hexagon Bar | 6–200 mm | ASTM A484/A484M | 3–6 m random |
| T&P / Ground Bar | All sizes | ASTM A484/A484M (T&P) | Cut-to-length |
Hot-rolled round bar: ±0.5 mm for 25–50 mm dia.; ±1.0 mm for 50–100 mm dia. Cold-drawn: h9–h11 tolerances (much tighter). Full tables in ASTM A484/A484M.
| Industry | Recommended Grades | Typical Components |
|---|---|---|
| Machined Parts | 303, 416, 420, 430F | Auto screw machine parts, fittings, adapters |
| Shafts & Rotors | 304, 316, 410, 17-4PH | Pump shafts, motor shafts, rotor bars |
| Fasteners | 302, 304, 410, 316L | Bolts, screws, pins, lock washers |
| Medical & Surgical | 304L, 316L, 420, 440C | Implants, surgical instruments, pins |
| Food Processing | 304L, 316L | Mixer shafts, pump impellers, trays |
| Aerospace | 17-4PH, 17-7PH, 321, 347 | Landing gear, turbine parts, springs |
| Criteria | ASTM A276 | ASTM A479 |
|---|---|---|
| Application | General engineering | Boilers and pressure vessels |
| Annealing | Required for austenitic if specified | Mandatory; must be documented |
| Hardness Test | Per lot | Each end of each bar (mandatory) |
| ASME BPVC | Not adopted | Adopted as SA-479 |
| Cost | More economical | Higher (more testing) |
| Standard | Scope | Relationship |
|---|---|---|
| ASTM A479 | Stainless Steel Bars for Pressure Vessels | Pressure vessel alternative to A276 |
| ASTM A484/A484M | General Requirements for Stainless Steel Bars | Dimensional & tolerance standard |
| ASTM A370 | Mechanical Testing of Steel Products | Tensile, hardness test methods |
| ASTM A262 | Sensitization / IGC Testing | Supplementary requirement |
| No. | Item | Requirement / Example |
|---|---|---|
| 1 | Specification | ASTM A276 or A276M |
| 2 | Grade / Type | e.g., Type 303 (UNS S30300) |
| 3 | Product Form | Round, square, hexagon, flat bar |
| 4 | Size / Dimensions | e.g., Round 25 mm dia. × 3 m |
| 5 | Surface Finish | Hot-rolled; CD (cold-drawn); T&P; ground |
| 6 | Condition | Annealed; cold-worked; aged (for PH grades) |
| 7 | Certification | EN 10204 3.1 CMTR |
| 8 | Quantity | Weight (kg / metric ton) |
ASTM A276 covers stainless steel bars for general engineering: machined components (shafts, fittings, adapters), fasteners (bolts, screws), springs (302, 17-7PH), medical instruments (304L, 316L, 420, 440C), and structural parts in the food, pharmaceutical, chemical, and marine industries.
A276 is a general-purpose bar specification for machined parts and mechanical components. A479 is written specifically for boilers and pressure vessels with mandatory end hardness testing on every bar, mandatory documented solution annealing, and ASME BPVC adoption (SA-479). A276 is more economical for non-Code applications.
No. Type 303 (free-machining, S 0.15% min) is specifically excluded from ASTM A479 (pressure vessel bars) and ASME SA-479. For pressure vessel use, use Type 304 or 316 bars to A479/SA-479 with proper annealing and traceability documentation.
17-4PH (ASTM A564 Type 630, also covered by A276) is a precipitation-hardening stainless steel achieving tensile strengths up to 1310 MPa (190 ksi) after aging. Used in aerospace landing gear, nuclear reactor components, valve stems, pump shafts, and high-strength corrosion-resistant mechanical parts.
Cold-drawn (CD) bars offer the best combination of machinability and cost: bright smooth surface, tight tolerances (h9–h11), and minimal material allowance. For high-precision or final-dimension parts, specify turned and polished (T&P) or ground bars. Hot-rolled bars (black oxide) are most economical but require more machining allowance.
ASTM A276 Type 316L (UNS S31603): minimum tensile strength 485 MPa (70 ksi), minimum yield strength 0.2% offset 170 MPa (25 ksi), elongation min. 40% in 2 in., hardness max. 217 HB / 95 HRB, in the annealed condition. Note: cold-drawn 316L bars typically achieve ~620 MPa tensile / ~310 MPa yield in the as-drawn condition.
HT PIPE stocks and supplies ASTM A276 stainless steel bars in hot-rolled, cold-drawn, and T&P finishes across all standard grades (303, 304, 316, 321, 347, 410, 416, 420, 430, 17-4PH and more). EN 10204 3.1 CMTRs included.