Steel S5 · heat-treated state
Steel S5 Hardened & Tempered
Properties of the Hardened & Tempered condition, compared with the other S5 tempers.
Maximum hardness/wear condition for punches and shear blades where impact loads are moderate.
What is S5 Hardened & Tempered?
S5 Hardened & Tempered is S5 heat treated to Hardened & Tempered — maximum hardness/wear condition for punches and shear blades where impact loads are moderate. S5 Hardened & Tempered has a yield strength of 1,850 MPa (268 ksi) and a tensile strength of 2,150 MPa (312 ksi) — stronger than 99% of steel grades. Elongation at break is 4% and the elastic modulus is 207 GPa (30 Msi). S5 Hardened & Tempered has a density of 7.76 g/cm³ (0.28 lb/in³), lighter than 92% of steel grades. It melts at 1,420°C (2,588 °F). Annealed is the default condition FabDigit quotes; Hardened & Tempered is available on request or by drawing note.
Advantages
- High strength — 1,850 MPa (268 ksi), better than 99% of steel grades
Limitations
- Limited service temperature — 175°C (347 °F), worse than 99% of steel grades
- Limited ductility — 4%, worse than 98% of steel grades
- Poor heat conductor — 24 W/m·K (13.9 BTU/hr·ft·°F), worse than 90% of steel grades
- High embodied carbon — 2.6 kg CO₂/kg, worse than 86% of steel grades
- Low electrical conductivity — 4 % IACS, worse than 83% of steel grades
S5 Hardened & Tempered properties
Typical room-temperature values for S5 Hardened & Tempered — 13 properties are specific to this condition; the rest are grade-level values shared by every S5 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
S5 Hardened & Tempered has a density of 7.76 g/cm³ (0.28 lb/in³), lighter than 92% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical15
S5 Hardened & Tempered has a yield strength of 1,850 MPa (268 ksi) and a tensile strength of 2,150 MPa (312 ksi) — stronger than 99% of steel grades. Elongation at break is 4% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
S5 Hardened & Tempered is rated for continuous service to 175°C (347 °F). It conducts heat at 24 W/m·K (13.9 BTU/hr·ft·°F), worse than 90% of steel grades. Thermal expansion is 12.4 µm/m·K (6.89 µin/in·°F).
Electrical3
S5 Hardened & Tempered conducts electricity at 4 % IACS, worse than 83% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of S5 Hardened & Tempered takes about 36 MJ of energy and emits 2.6 kg of CO₂ — more than 88% of steel grades. Typical recycled content is 40%.
Manufacturability8
S5 Hardened & Tempered's machinability is fair (50/100, worse than 53% of steel grades); weldability poor (25/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other S5 tempers and conditions
S5 is also supplied in 4 other conditions. The full side-by-side table is on the S5 overview.
- AnnealedDefaultStandard stock condition for machining tools before hardening.440 MPa yield · 215 HB
- Hardened & TemperedMaximum hardness/wear condition for punches and shear blades where impact loads are moderate.1,850 MPa yield · 59 HRC
- Q&TTougher working condition (temper ~315–400 °C) for chisels, rivet sets and heavy shock tooling.1,500 MPa yield · 53 HRC
Working with S5 Hardened & Tempered
Is S5 easy to machine?
Machine in the annealed condition (~215 HB) with sharp carbide or HSS tooling; the ~2% Si makes chips gummy, so use positive rake, rigid setups and flood coolant, and finish-grind after hardening.
Can S5 be welded?
Only repair welding is advised: preheat 300–350 °C, use matching or low-hydrogen electrodes, keep interpass heat, then temper immediately at the part's tempering temperature.
Can S5 be formed, bent or molded?
Hot forge 1040–1100 °C, stop above ~900 °C and slow-cool, then spheroidize anneal 760–790 °C; cold forming is limited to light bending in the annealed state.
What surface finishes work on S5?
Harden from 870 °C in oil (or interrupted/marquench), temper at 175–425 °C for 50–60 HRC; protect with black oxide, phosphate or oil — no anodizing, and avoid hard chrome above the temper temperature.
S5 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 |
|---|---|---|
| C | 0.5 – 0.65 | 0.58 |
| Sihigh Si gives the shock-resisting character | 1.75 – 2.25 | 2 |
| Mn | 0.6 – 1 | 0.8 |
| Mo | 0.2 – 1.35 | 0.4 |
| Croptional addition per ASTM A681 | ≤ 0.5 | 0.3 |
| Voptional, grain refinement | ≤ 0.35 | 0.2 |
| Niresidual | ≤ 0.3 | — |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
S5 Hardened & Tempered — frequently asked
What is S5 Hardened & Tempered used for?
S5 Hardened & Tempered is typically used for pneumatic chisels, punches, shear and cropping blades, rivet sets and chipping hammers, cold heading and stamping tooling and impact drivers and screwdriver bits. In short: shock-resistant tool steel.
What is the yield strength of S5 Hardened & Tempered?
S5 Hardened & Tempered has a typical yield strength of 1,850 MPa (268 ksi) and a tensile strength of 2,150 MPa (312 ksi) — stronger than 99% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is S5 Hardened & Tempered easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machine in the annealed condition (~215 HB) with sharp carbide or HSS tooling; the ~2% Si makes chips gummy, so use positive rake, rigid setups and flood coolant, and finish-grind after hardening.
Can S5 Hardened & Tempered be welded?
Not readily — weldability is rated poor (25/100). Only repair welding is advised: preheat 300–350 °C, use matching or low-hydrogen electrodes, keep interpass heat, then temper immediately at the part's tempering temperature.
What surface finishes work on S5 Hardened & Tempered?
Harden from 870 °C in oil (or interrupted/marquench), temper at 175–425 °C for 50–60 HRC; protect with black oxide, phosphate or oil — no anodizing, and avoid hard chrome above the temper temperature.
Can S5 Hardened & Tempered be formed, bent or molded?
Hot forge 1040–1100 °C, stop above ~900 °C and slow-cool, then spheroidize anneal 760–790 °C; cold forming is limited to light bending in the annealed state.
What is the maximum service temperature of S5 Hardened & Tempered?
S5 Hardened & Tempered is rated for continuous use to about 175°C (347 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in S5 Hardened & Tempered?
Yes — S5 Hardened & Tempered is available for CNC machining with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A681 – Standard Specification for Tool Steels Alloy — ASTM International (2015)
- ASM Handbook Vol.1: Properties and Selection – Irons, Steels, and High-Performance Alloys (Tool Steels) — ASM International (1990)
- Tool Steels, 5th Edition (Roberts, Krauss, Kennedy) — ASM International (1998)
- ASM Handbook Vol.16: Machining — ASM International (1989)
- MatWeb AISI S5 tool steel datasheets — MatWeb LLC (2024)
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.