Steel A6 As-Quenched
Heat-treated state
AISI/SAE A6 · UNS T30106
Transient condition only — measure hardness then temper immediately; never put into service untempered.
Values for the As-Quenched condition
Other A6 tempers and conditions
A6 is listed in 4 conditions; see the grade overview at A6.
- Annealed
- H&T 50-54 HRC
- Hardened & Tempered
- As-Quenched
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault soft, machinable supply condition | Standard mill/stock condition for bar, plate and flat ground stock; machine to shape here, then harden. | 415 | 725 | 22 | 235 HB | — |
High-temper condition for maximum toughness | Temper near 400–480 °C for shear blades, heavy punches and shock tools where chipping is the failure mode. | 1,500 | 1,750 | 5 | 52 HRC | 2.7 % IACS |
air quenched 845–870 °C, tempered 175–190 °C (58–60 HRC) | Standard working condition for blanking, trimming and forming dies where maximum wear resistance is wanted. | 1,800 | 2,100 | 2 | 59 HRC | — |
As-QuenchedThis page air hardened from 845–870 °C, untempered (60–63 HRC) | Transient condition only — measure hardness then temper immediately; never put into service untempered. | 2,000 | 2,300 | 0.5 | 62 HRC | 2.6 % IACS |
What is A6 As-Quenched?
A6 As-Quenched is A6 heat treated to As-Quenched — transient condition only — measure hardness then temper immediately; never put into service untempered. A6 As-Quenched has a yield strength of 2,000 MPa (290 ksi) and a tensile strength of 2,300 MPa (334 ksi) — stronger than 100% of steel grades. Elongation at break is 0.5% and the elastic modulus is 207 GPa (30 Msi). A6 As-Quenched has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,425°C (2,597 °F). Annealed is the default condition FabDigit quotes; As-Quenched is available on request or by drawing note.
Advantages
- High strength — 2,000 MPa (290 ksi), better than 100% of steel grades
Limitations
- Limited ductility — 0.5%, worse than 100% of steel grades
- Difficult to machine — 3/100, worse than 100% of steel grades
- Difficult to weld — 5/100, worse than 100% of steel grades
- Limited formability — 2/100, worse than 100% of steel grades
- Limited service temperature — 150°C (302 °F), worse than 99% of steel grades
A6 As-Quenched properties
Typical room-temperature values for A6 As-Quenched; 22 are specific to this condition. Other listed values are A6 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
A6 As-Quenched has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical15
A6 As-Quenched has a yield strength of 2,000 MPa (290 ksi) and a tensile strength of 2,300 MPa (334 ksi) — stronger than 100% of steel grades. Elongation at break is 0.5% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
A6 As-Quenched is rated for continuous service to 150°C (302 °F). It conducts heat at 24 W/m·K (13.9 BTU/hr·ft·°F), worse than 90% of steel grades. Thermal expansion is 11.8 µm/m·K (6.56 µin/in·°F).
Electrical2
A6 As-Quenched has an electrical resistivity of 6.5×10⁻⁷ Ω·m.
Chemical & Environmental2
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of A6 As-Quenched takes about 34 MJ of energy and emits 2.6 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 45%.
Manufacturability8
A6 As-Quenched's machinability is not recommended (3/100, worse than 100% of steel grades); weldability not recommended (5/100); formability not recommended (2/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with A6 As-Quenched
Is A6 easy to machine?
Machine in the annealed condition with sharp carbide or cobalt HSS tooling and rigid setups; leave 0.1–0.3 mm grinding stock, as hardened A6 needs grinding or EDM only.
Can A6 be welded?
Weldable only for die repair — preheat to 250–300 °C, use matching or tool-steel filler with small stringer beads, and temper immediately after cooling to ~150 °C.
Can A6 be formed, bent or molded?
Cold forming is limited to mild bending of annealed stock; hot work 900–1050 °C, then cool slowly and full anneal at ~745–790 °C with slow furnace cooling.
What surface finishes work on A6?
Harden in air from 845–870 °C (use a neutral atmosphere or foil wrap to prevent decarburization), temper twice, then grind, polish, or apply black oxide, nitriding or PVD for extra wear life.
A6 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 | 0.65 – 0.75 | 0.7 |
| Mnhigh Mn gives deep air hardening from low austenitizing temperature | 1.8 – 2.5 | 2.1 |
| Si | ≤ 0.5 | 0.3 |
| Cr | 0.9 – 1.2 | 1.05 |
| Mo | 0.9 – 1.4 | 1.15 |
| Niresidual | ≤ 0.3 | — |
| Voptional grain refiner | ≤ 0.3 | — |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
A6 As-Quenched — frequently asked
What is A6 As-Quenched used for?
A6 As-Quenched is typically used for cold-work blanking and piercing dies, trim and form die inserts, gauges and master fixtures, punches and stripper plates, shear blades for thin stock and bushings and locating pins. In short: workhorse air-hardening tool.
What is the yield strength of A6 As-Quenched?
A6 As-Quenched has a typical yield strength of 2,000 MPa (290 ksi) and a tensile strength of 2,300 MPa (334 ksi) — stronger than 100% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is A6 As-Quenched easy to machine?
Not especially — machinability is rated not recommended (3/100, worse than 100% of steel grades). Machine in the annealed condition with sharp carbide or cobalt HSS tooling and rigid setups; leave 0.1–0.3 mm grinding stock, as hardened A6 needs grinding or EDM only.
Can A6 As-Quenched be welded?
Not readily — weldability is rated not recommended (5/100). Weldable only for die repair — preheat to 250–300 °C, use matching or tool-steel filler with small stringer beads, and temper immediately after cooling to ~150 °C.
What surface finishes work on A6 As-Quenched?
Harden in air from 845–870 °C (use a neutral atmosphere or foil wrap to prevent decarburization), temper twice, then grind, polish, or apply black oxide, nitriding or PVD for extra wear life.
Can A6 As-Quenched be formed, bent or molded?
Cold forming is limited to mild bending of annealed stock; hot work 900–1050 °C, then cool slowly and full anneal at ~745–790 °C with slow furnace cooling.
What is the maximum service temperature of A6 As-Quenched?
A6 As-Quenched is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in A6 As-Quenched?
Yes — A6 As-Quenched is available for CNC machining; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A681 — Standard Specification for Tool Steels Alloy — ASTM International (2022)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (Tool Steels) — ASM International (1990)
- Tool Steels, 5th ed. (Roberts, Krauss, Kennedy) — ASM International (1998)
- A6 air-hardening tool steel datasheet — Crucible / Latrobe / Hudson Tool Steel (2020)
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.