Stainless Steel 316Cb-1/4 Hard
Supply condition
UNS S31640 · EN 1.4580
1/4 Hard = quarter hard
Light cold-rolled temper when moderately higher strength is needed but some bending ductility must remain.
Values for the 1/4 Hard condition
Other 316Cb tempers and conditions
316Cb is listed in 7 conditions; see the grade overview at 316Cb.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot Finished / Hot Rolled + Annealed bar (ASTM A276) | Economical large-diameter bar and shapes for machined weldments where surface finish and tight tolerance are not critical. | 245 | 560 | 45 | 160 HB | 2.3 % IACS |
AnnealedDefault solution annealed (1040–1120 °C, rapid cool), plate/sheet/bar | Standard stocked condition: maximum corrosion resistance, ductility and weldability for fabricated vessels and piping. | 250 | 570 | 45 | 155 HB | — |
annealed and cold drawn bar/wire | Pick for higher yield strength, straightness and good machined finish in fasteners, shafts and fittings. | 480 | 690 | 28 | 215 HB | — |
1/4 HardThis page Quarter hard | Light cold-rolled temper when moderately higher strength is needed but some bending ductility must remain. | 560 | 900 | 12 | 25 HRC | 2.3 % IACS |
Half hard | Structural strip and springs where strength matters more than deep forming. | 800 | 1,070 | 8 | 32 HRC | 2.3 % IACS |
Three-quarter hard | High-strength strip for flat springs, clamps and shims with only simple bends. | 965 | 1,240 | 5 | 38 HRC | 2.3 % IACS |
cold rolled strip (ASTM A666 temper) | Maximum cold-worked strength/spring temper; essentially no formability beyond flat blanking. | 1,010 | 1,320 | 3 | 41 HRC | 2.3 % IACS |
What is 316Cb-1/4 Hard?
316Cb-1/4 Hard is 316Cb supplied in the 1/4 Hard condition — light cold-rolled temper when moderately higher strength is needed but some bending ductility must remain. 316Cb-1/4 Hard has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 85% of stainless steel grades. Elongation at break is 12% and the elastic modulus is 193 GPa (28 Msi). 316Cb-1/4 Hard has a density of 7.98 g/cm³ (0.288 lb/in³), heavier than 85% of stainless steel grades. It melts at 1,375°C (2,507 °F). Annealed is the default condition FabDigit quotes; 1/4 Hard is available on request or by drawing note.
Advantages
- High strength — 560 MPa (81.2 ksi), better than 85% of stainless steel grades
- Readily welded — 80/100, better than 80% of stainless steel grades
Limitations
- Limited ductility — 12%, worse than 95% of stainless steel grades
- Limited service temperature — 300°C (572 °F), worse than 90% of stainless steel grades
- High embodied carbon — 5.6 kg CO₂/kg, worse than 83% of stainless steel grades
316Cb-1/4 Hard properties
Typical room-temperature values for 316Cb-1/4 Hard; 24 are specific to this condition. Other listed values are 316Cb reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
316Cb-1/4 Hard has a density of 7.98 g/cm³ (0.288 lb/in³), heavier than 85% of stainless steel grades. It melts at 1,375°C (2,507 °F).
Mechanical16
316Cb-1/4 Hard has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 85% of stainless steel grades. Elongation at break is 12% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
316Cb-1/4 Hard is rated for continuous service to 300°C (572 °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
316Cb-1/4 Hard conducts electricity at 2.3 % IACS, better than 55% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), better than 63% of stainless steel grades.
Sustainability4
Producing a kilogram of 316Cb-1/4 Hard takes about 75 MJ of energy and emits 5.6 kg of CO₂ — more than 84% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
316Cb-1/4 Hard's machinability is fair (38/100, better than 63% of stainless steel grades); weldability very good (80/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 316Cb-1/4 Hard
Is 316Cb easy to machine?
Machine like 316 but expect harder NbC particles: rigid setups, sharp coated carbide, 25–60 m/min, heavy positive feed to avoid work-hardened glaze, flood coolant.
Can 316Cb be welded?
Excellent with GTAW/GMAW/SMAW using ER/E 318 (Nb-bearing) or 316L filler; no post-weld anneal needed for sensitization control, keep heat input moderate and interpass low to limit distortion.
Can 316Cb be formed, bent or molded?
Cold forms and deep draws well in the annealed temper but work-hardens rapidly — allow 30–50% more press force than carbon steel and interstage anneal for severe draws; hot work 1150–1200 °C, then solution anneal.
What surface finishes work on 316Cb?
Pickle and passivate per ASTM A967 (or electropolish) after welding to restore the passive film; not anodizable, takes mechanical No.4 to No.8 mirror finishes.
316Cb 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 |
|---|---|---|
| CNb ≥ 10 × C required | ≤ 0.08 | 0.05 |
| Mn | ≤ 2 | 1.5 |
| Si | ≤ 0.75 | 0.5 |
| P | ≤ 0.05 | — |
| S | ≤ 0.03 | — |
| Cr | 16 – 18 | 17 |
| Ni | 10 – 14 | 12 |
| Mo | 2 – 3 | 2.5 |
| Nb10 × C min; Nb (+Ta) stabilizer | ≤ 1.1 | 0.6 |
| N | ≤ 0.1 | — |
| Fe | balance | — |
316Cb-1/4 Hard — frequently asked
What is 316Cb-1/4 Hard used for?
316Cb-1/4 Hard is typically used for welded chemical process piping, high-temperature service vessels, heat exchanger shells and tubing, expansion bellows and joints, furnace and flue components and weld overlay and fabricated ducting. In short: nb-stabilized 316; no post-weld anneal needed; resists intergranular attack.
What is the yield strength of 316Cb-1/4 Hard?
316Cb-1/4 Hard has a typical yield strength of 560 MPa (81.2 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 85% of stainless steel grades. Strength varies by condition: see the 7 listed tempers.
Is 316Cb-1/4 Hard easy to machine?
Not especially — machinability is rated fair (38/100, better than 63% of stainless steel grades). Machine like 316 but expect harder NbC particles: rigid setups, sharp coated carbide, 25–60 m/min, heavy positive feed to avoid work-hardened glaze, flood coolant.
Can 316Cb-1/4 Hard be welded?
Yes — weldability is rated very good (80/100). Excellent with GTAW/GMAW/SMAW using ER/E 318 (Nb-bearing) or 316L filler; no post-weld anneal needed for sensitization control, keep heat input moderate and interpass low to limit distortion.
What surface finishes work on 316Cb-1/4 Hard?
Pickle and passivate per ASTM A967 (or electropolish) after welding to restore the passive film; not anodizable, takes mechanical No.4 to No.8 mirror finishes.
Can 316Cb-1/4 Hard be formed, bent or molded?
Cold forms and deep draws well in the annealed temper but work-hardens rapidly — allow 30–50% more press force than carbon steel and interstage anneal for severe draws; hot work 1150–1200 °C, then solution anneal.
What is the maximum service temperature of 316Cb-1/4 Hard?
316Cb-1/4 Hard is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip — ASTM (2022)
- ASTM A276/A276M — Stainless Steel Bars and Shapes — ASTM (2017)
- ASTM A666 — Annealed or Cold-Worked Austenitic Stainless Steel Sheet, Strip, Plate and Flat Bar — ASTM (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)
- SAE/ASTM Unified Numbering System for Metals and Alloys (UNS S31640) — SAE/ASTM (2017)
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.