Steel Cr12 · hardness band
Steel Cr12 Q&T 55-58 HRC
Properties of the Q&T 55-58 HRC condition, compared with the other Cr12 tempers.
Choose when the tool sees edge chipping or impact and some wear resistance can be traded for toughness.
What is Cr12 Q&T 55-58 HRC?
Cr12 Q&T 55-58 HRC is Cr12 heat treated to Q&T 55-58 HRC — choose when the tool sees edge chipping or impact and some wear resistance can be traded for toughness. Cr12 Q&T 55-58 HRC has a yield strength of 1,550 MPa (225 ksi) and a tensile strength of 1,800 MPa (261 ksi) — stronger than 97% of steel grades. Elongation at break is 2% and the elastic modulus is 210 GPa (30.5 Msi). Cr12 Q&T 55-58 HRC has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 95% of steel grades. It melts at 1,400°C (2,552 °F). Annealed is the default condition FabDigit quotes; Q&T 55-58 HRC is available on request or by drawing note.
Advantages
- High strength — 1,550 MPa (225 ksi), better than 97% of steel grades
- Good corrosion resistance — 24/100, better than 90% of steel grades
- Polishes to a fine finish — 70/100, better than 87% of steel grades
Limitations
- Difficult to machine — 10/100, worse than 100% of steel grades
- Limited ductility — 2%, worse than 99% of steel grades
- Poor heat conductor — 20 W/m·K (11.6 BTU/hr·ft·°F), worse than 96% of steel grades
- Low electrical conductivity — 2.7 % IACS, worse than 96% of steel grades
- Difficult to weld — 12/100, worse than 96% of steel grades
Cr12 Q&T 55-58 HRC properties
Typical room-temperature values for Cr12 Q&T 55-58 HRC — 9 properties are specific to this condition; the rest are grade-level values shared by every Cr12 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
Cr12 Q&T 55-58 HRC has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 95% of steel grades. It melts at 1,400°C (2,552 °F).
Mechanical13
Cr12 Q&T 55-58 HRC has a yield strength of 1,550 MPa (225 ksi) and a tensile strength of 1,800 MPa (261 ksi) — stronger than 97% of steel grades. Elongation at break is 2% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
Cr12 Q&T 55-58 HRC is rated for continuous service to 300°C (572 °F). It conducts heat at 20 W/m·K (11.6 BTU/hr·ft·°F), worse than 96% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
Cr12 Q&T 55-58 HRC conducts electricity at 2.7 % IACS, worse than 96% of steel grades.
Chemical & Environmental2
Corrosion resistance is poor (24/100), better than 90% of steel grades.
Sustainability4
Producing a kilogram of Cr12 Q&T 55-58 HRC takes about 36 MJ of energy and emits 2.6 kg of CO₂ — more than 88% of steel grades. Typical recycled content is 45%.
Manufacturability8
Cr12 Q&T 55-58 HRC's machinability is not recommended (10/100, worse than 100% of steel grades); weldability not recommended (12/100); formability not recommended (12/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other Cr12 tempers and conditions
Cr12 is also supplied in 5 other conditions. The full side-by-side table is on the Cr12 overview.
- AnnealedDefaultStandard delivery condition for machining and die sinking before hardening.480 MPa yield · 22 HRC
- Hardened & TemperedPeak-hardness setting for pure abrasive wear (thread rolling dies, wire drawing dies, cold extrusion inserts) where shock loading is absent.2,100 MPa tensile
- Q&TGeneral hardened die condition: maximum wear resistance for blanking and drawing tools with modest impact.1,700 MPa yield · 61 HRC
- Q&T 55-58 HRCChoose when the tool sees edge chipping or impact and some wear resistance can be traded for toughness.1,550 MPa yield · 57 HRC
Working with Cr12 Q&T 55-58 HRC
Is Cr12 easy to machine?
Machine only in the annealed state with rigid setups, low speeds and coated carbide/TiAlN tooling; abrasive carbides cause fast edge wear, and above ~58 HRC use CBN grinding or EDM.
Can Cr12 be welded?
Essentially not weldable in service; repair welding requires 400–500 °C preheat, matching high-Cr electrode, immediate post-weld temper and slow cooling to avoid quench cracks.
Can Cr12 be formed, bent or molded?
Hot forge 1050–1100 °C, stop above 900 °C, cool slowly in furnace then spheroidize anneal 840–870 °C; virtually no cold forming capability.
What surface finishes work on Cr12?
Takes a fine ground/lapped finish but coarse carbides limit true mirror polish; protect with nitriding, hard chrome or PVD TiN/CrN and oil rust-preventive during storage.
Cr12 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 |
|---|---|---|
| CGB/T 1299 Cr12 | 2 – 2.3 | 2.15 |
| Cr | 11.5 – 13 | 12.2 |
| Si | 0.1 – 0.4 | 0.3 |
| Mn | 0.15 – 0.4 | 0.3 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Niresidual, max | ≤ 0.25 | — |
| Curesidual, max | ≤ 0.3 | — |
| Monot intentionally added (unlike Cr12MoV) | ≤ 0.3 | — |
| Fe | balance | — |
Cr12 Q&T 55-58 HRC — frequently asked
What is Cr12 Q&T 55-58 HRC used for?
Cr12 Q&T 55-58 HRC is typically used for cold blanking and piercing dies, thread-rolling dies, wire and tube drawing dies, shear and slitter blades, cold-forming rolls and punches for thin sheet. In short: cold-work die tool.
What is the yield strength of Cr12 Q&T 55-58 HRC?
Cr12 Q&T 55-58 HRC has a typical yield strength of 1,550 MPa (225 ksi) and a tensile strength of 1,800 MPa (261 ksi) — stronger than 97% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is Cr12 Q&T 55-58 HRC easy to machine?
Not especially — machinability is rated not recommended (10/100, worse than 100% of steel grades). Machine only in the annealed state with rigid setups, low speeds and coated carbide/TiAlN tooling; abrasive carbides cause fast edge wear, and above ~58 HRC use CBN grinding or EDM.
Can Cr12 Q&T 55-58 HRC be welded?
Not readily — weldability is rated not recommended (12/100). Essentially not weldable in service; repair welding requires 400–500 °C preheat, matching high-Cr electrode, immediate post-weld temper and slow cooling to avoid quench cracks.
What surface finishes work on Cr12 Q&T 55-58 HRC?
Takes a fine ground/lapped finish but coarse carbides limit true mirror polish; protect with nitriding, hard chrome or PVD TiN/CrN and oil rust-preventive during storage.
Can Cr12 Q&T 55-58 HRC be formed, bent or molded?
Hot forge 1050–1100 °C, stop above 900 °C, cool slowly in furnace then spheroidize anneal 840–870 °C; virtually no cold forming capability.
What is the maximum service temperature of Cr12 Q&T 55-58 HRC?
Cr12 Q&T 55-58 HRC 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.
Can FabDigit make parts in Cr12 Q&T 55-58 HRC?
Yes — Cr12 Q&T 55-58 HRC is available for CNC machining with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- GB/T 1299 (Alloy tool steels) — SAC (2014)
- ASTM A681 Standard Specification for Tool Steels Alloy (D3) — ASTM (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (tool steels) — ASM International (1990)
- ASM Handbook Vol.16 — Machining (tool steel machinability ratings) — ASM International (1989)
- X210Cr12 / 1.2080 cold work tool steel datasheet — Böhler / Voestalpine (2020)
- Cr12/Cr12MoV — Mysteel / 1688 (2025)
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.