Stainless Steel 316 · supply condition
Stainless Steel 316 A4-70
Properties of the A4-70 condition, compared with the other 316 tempers.
Standard property class for 316 bolts and screws — 700 MPa minimum tensile from cold forming/drawing.
What is 316 A4-70?
316 A4-70 is 316 supplied in the A4-70 condition — standard property class for 316 bolts and screws — 700 MPa minimum tensile from cold forming/drawing. 316 A4-70 has a yield strength of 500 MPa (72.5 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 77% of stainless steel grades. Elongation at break is 25% and the elastic modulus is 193 GPa (28 Msi). 316 A4-70 has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,375°C (2,507 °F). Solution Annealed is the default condition FabDigit quotes; A4-70 is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 220 MPa·√m (200.2 ksi·√in), better than 97% of stainless steel grades
- Polishes to a fine finish — 85/100, better than 97% of stainless steel grades
- Forms and bends easily — 85/100, better than 95% of stainless steel grades
- Readily welded — 88/100, better than 91% of stainless steel grades
- Good corrosion resistance — 74/100, better than 78% of stainless steel grades
Limitations
- Limited service temperature — 400°C (752 °F), worse than 78% of stainless steel grades
316 A4-70 properties
Typical room-temperature values for 316 A4-70 — 8 properties are specific to this condition; the rest are grade-level values shared by every 316 temper. Each bar shows where the value sits among the stainless steel grades in FabDigit's library — further right is higher.
Physical3
316 A4-70 has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,375°C (2,507 °F).
Mechanical16
316 A4-70 has a yield strength of 500 MPa (72.5 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 77% of stainless steel grades. Elongation at break is 25% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
316 A4-70 is rated for continuous service to 400°C (752 °F). It conducts heat at 16.3 W/m·K (9.42 BTU/hr·ft·°F), better than 68% of stainless steel grades. Thermal expansion is 16 µm/m·K (8.89 µin/in·°F).
Electrical3
316 A4-70 conducts electricity at 2.3 % IACS, better than 55% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (74/100), better than 78% of stainless steel grades.
Sustainability4
Producing a kilogram of 316 A4-70 takes about 57 MJ of energy and emits 5.1 kg of CO₂ — more than 61% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
316 A4-70's machinability is fair (35/100, better than 51% of stainless steel grades); weldability excellent (88/100); formability excellent (85/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 316 tempers and conditions
316 is also supplied in 9 other conditions. The full side-by-side table is on the 316 overview.
- Solution AnnealedDefaultStandard as-supplied condition for plate, sheet, bar, tube and fittings — maximum corrosion resistance, ductility and toughness.290 MPa yield · 150 HB
- Full HardMaximum strength/spring temper strip; essentially unformable except for large-radius bends.1,000 MPa yield · 40 HRC
- 1/2 HardHigher strength strip for flat springs, shims and load-bearing brackets where only gentle bends are needed.800 MPa yield · 32 HRC
- 1/4 HardModest strength boost while retaining some bendability — springs, clips, structural strip.560 MPa yield · 25 HRC
- Cold DrawnChoose for straight, close-tolerance bar with higher yield strength and better chip control on screw machines.515 MPa yield · 200 HB
- A4-70Standard property class for 316 bolts and screws — 700 MPa minimum tensile from cold forming/drawing.500 MPa yield · 99 HRB
- Cold RolledStandard thin sheet/coil product with a smooth 2B or bright-annealed surface; slightly higher strength than plate, excellent for forming and polishing.310 MPa yield · 160 HB
- AnnealedUsed interchangeably with solution annealed on mill certificates for austenitic 316; pick when the certificate simply says 'annealed'.285 MPa yield · 150 HB
Working with 316 A4-70
Is 316 easy to machine?
Runs gummy and work-hardens fast: use sharp positive-rake carbide, 30–60 m/min for turning, heavy constant feed (never dwell), rigid setups and flood coolant or high-pressure through-tool.
Can 316 be welded?
Readily welded by GTAW/GMAW/SMAW/laser with 316L or 316LSi filler and Ar (or Ar+2 %CO₂) shielding; no preheat, keep interpass <150 °C, purge root, avoid 425–815 °C dwell to prevent sensitization/sigma, then pickle-passivate.
Can 316 be formed, bent or molded?
Excellent deep-drawing and bending in the annealed condition (bend radius ≥1t for thin sheet) but ~50 % more press force and more springback than mild steel; anneal at 1050 °C between severe draws.
What surface finishes work on 316?
Not anodizable — specify mill 2B/BA, No.4 brush, or No.8 mirror; passivate per ASTM A967 or electropolish after machining/welding, and PVD-coat for coloured decorative finishes.
316 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 |
|---|---|---|
| C316L variant ≤0.030 | ≤ 0.08 | 0.05 |
| Mn | ≤ 2 | 1.5 |
| SiEN 1.4401 limit 1.00 | ≤ 0.75 | 0.5 |
| P | ≤ 0.05 | 0.03 |
| S | ≤ 0.03 | 0.01 |
| Cr | 16 – 18 | 17 |
| Ni | 10 – 14 | 11 |
| Mo | 2 – 3 | 2.3 |
| N | ≤ 0.1 | 0.04 |
| Febalance ≈ 65–69 % | balance | — |
316 A4-70 — frequently asked
What is 316 A4-70 used for?
316 A4-70 is typically used for marine deck hardware and fasteners, chemical process piping and tanks, food and pharmaceutical processing equipment, surgical instruments and implants, heat exchanger tubing and pump and valve components. In short: marine grade expert.
What is the yield strength of 316 A4-70?
316 A4-70 has a typical yield strength of 500 MPa (72.5 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 77% of stainless steel grades. Strength varies by condition: see the 10 listed tempers.
Is 316 A4-70 easy to machine?
Not especially — machinability is rated fair (35/100, better than 51% of stainless steel grades). Runs gummy and work-hardens fast: use sharp positive-rake carbide, 30–60 m/min for turning, heavy constant feed (never dwell), rigid setups and flood coolant or high-pressure through-tool.
Can 316 A4-70 be welded?
Yes — weldability is rated excellent (88/100). Readily welded by GTAW/GMAW/SMAW/laser with 316L or 316LSi filler and Ar (or Ar+2 %CO₂) shielding; no preheat, keep interpass <150 °C, purge root, avoid 425–815 °C dwell to prevent sensitization/sigma, then pickle-passivate.
What surface finishes work on 316 A4-70?
Not anodizable — specify mill 2B/BA, No.4 brush, or No.8 mirror; passivate per ASTM A967 or electropolish after machining/welding, and PVD-coat for coloured decorative finishes.
Can 316 A4-70 be formed, bent or molded?
Excellent deep-drawing and bending in the annealed condition (bend radius ≥1t for thin sheet) but ~50 % more press force and more springback than mild steel; anneal at 1050 °C between severe draws.
What is the maximum service temperature of 316 A4-70?
316 A4-70 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 316 Solution Annealed and 316 A4-80?
Solution Annealed is the default condition — standard as-supplied condition for plate, sheet, bar, tube and fittings — maximum corrosion resistance, ductility and toughness. A4-80: higher-strength 316 fastener grade for marine and structural bolting where 700 MPa is insufficient. Yield strength is 290 MPa in Solution Annealed versus 640 MPa in A4-80.
Can FabDigit make parts in 316 A4-70?
Yes — 316 A4-70 is available for CNC machining, sheet metal and casting & forging with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip — ASTM International (2023)
- ASTM A276/A276M — Stainless Steel Bars and Shapes — ASTM International (2023)
- ASTM A666 — Annealed or Cold-Worked Austenitic Stainless Steel Sheet, Strip, Plate and Flat Bar — ASTM International (2015)
- EN 10088-1/-2 — Stainless steels: list of grades and technical delivery conditions — CEN (2014)
- ISO 3506-1 — Mechanical properties of corrosion-resistant stainless steel fasteners — ISO (2020)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
- Outokumpu Supra 316/4401 datasheet & Corrosion Handbook — Outokumpu (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.