Steel S5 · temper · default condition
Steel S5 Annealed
Properties of the Annealed condition, compared with the other S5 tempers.
Standard stock condition for machining tools before hardening.
What is S5 Annealed?
S5 Annealed is S5 in the Annealed temper — standard stock condition for machining tools before hardening. S5 Annealed has a yield strength of 440 MPa (63.8 ksi) and a tensile strength of 725 MPa (105 ksi) — stronger than 51% of steel grades. Elongation at break is 25% and the elastic modulus is 207 GPa (30 Msi). S5 Annealed 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).
Advantages
- Ductile — tolerates forming and impact — 25%, better than 76% of steel grades
Limitations
- 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
- Difficult to weld — 25/100, worse than 77% of steel grades
S5 Annealed properties
Typical room-temperature values for S5 Annealed — 10 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 Annealed 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 Annealed has a yield strength of 440 MPa (63.8 ksi) and a tensile strength of 725 MPa (105 ksi) — stronger than 51% of steel grades. Elongation at break is 25% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
S5 Annealed is rated for continuous service to 400°C (752 °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 Annealed 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 Annealed 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 Annealed's machinability is fair (50/100, worse than 53% of steel grades); weldability poor (25/100); formability poor (30/100).
Common Calculations5
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 Annealed
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 Annealed — frequently asked
What is S5 Annealed used for?
S5 Annealed 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 Annealed?
S5 Annealed has a typical yield strength of 440 MPa (63.8 ksi) and a tensile strength of 725 MPa (105 ksi) — stronger than 51% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is S5 Annealed 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 Annealed 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 Annealed?
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 Annealed 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 Annealed?
S5 Annealed 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.
Can FabDigit make parts in S5 Annealed?
Yes — S5 Annealed 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.