Steel M36 H&T 67-68 HRC
Hardness band
AISI/SAE M36 · UNS T11336 · EN S6-5-2-5 · JIS SKH55 · GB W8Mo5Cr4V2Co5
H&T 67-68 HRC = hardened & Tempered to maximum hardness
Pick only for light-feed finishing or form tools cutting very abrasive material, where edge wear dominates over chipping.
Values for the H&T 67-68 HRC condition
Other M36 tempers and conditions
M36 is listed in 4 conditions; see the grade overview at M36.
- Annealed
- H&T + Nitrided
- H&T 67-68 HRC
- Hardened & Tempered
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault soft-annealed bar/flat as supplied for machining | Standard mill-supplied condition: machine and rough-grind the tool blank before hardening. | 550 | 880 | 14 | 248 HB | — |
Hardened & Tempered then surface-nitrided / steam-tempered | Choose for taps, hobs and gear cutters needing extra surface hardness and anti-galling on top of the hardened core. | 1,950 | 2,050 | 0.5 | 66 HRC | 2.6 % IACS |
H&T 67-68 HRCThis page Hardened & Tempered to maximum hardness | Pick only for light-feed finishing or form tools cutting very abrasive material, where edge wear dominates over chipping. | 2,000 | 2,100 | 0.5 | 68 HRC | 2.6 % IACS |
1200–1230 °C austenitize, oil/salt quench, triple temper 540–560 °C to 65–67 HRC | Normal working condition for cutting tools: maximum practical hot hardness and wear resistance. | 2,100 | 2,500 | 0.5 | 66 HRC | — |
What is M36 H&T 67-68 HRC?
M36 H&T 67-68 HRC is M36 heat treated to H&T 67-68 HRC — pick only for light-feed finishing or form tools cutting very abrasive material, where edge wear dominates over chipping. M36 H&T 67-68 HRC has a yield strength of 2,000 MPa (290 ksi) and a tensile strength of 2,100 MPa (305 ksi) — stronger than 100% of steel grades. Elongation at break is 0.5% and the elastic modulus is 220 GPa (31.9 Msi). M36 H&T 67-68 HRC has a density of 8.19 g/cm³ (0.296 lb/in³), heavier than 98% of steel grades. It melts at 1,400°C (2,552 °F). Annealed is the default condition FabDigit quotes; H&T 67-68 HRC is available on request or by drawing note.
Advantages
- High strength — 2,000 MPa (290 ksi), better than 100% of steel grades
- High service temperature — 620°C (1,148 °F), better than 99% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- Limited ductility — 0.5%, worse than 100% of steel grades
- Difficult to machine — 5/100, 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
- High embodied carbon — 4.6 kg CO₂/kg, worse than 96% of steel grades
M36 H&T 67-68 HRC properties
Typical room-temperature values for M36 H&T 67-68 HRC; 22 are specific to this condition. Other listed values are M36 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
M36 H&T 67-68 HRC has a density of 8.19 g/cm³ (0.296 lb/in³), heavier than 98% of steel grades. It melts at 1,400°C (2,552 °F).
Mechanical14
M36 H&T 67-68 HRC has a yield strength of 2,000 MPa (290 ksi) and a tensile strength of 2,100 MPa (305 ksi) — stronger than 100% of steel grades. Elongation at break is 0.5% and the elastic modulus is 220 GPa (31.9 Msi).
Thermal6
M36 H&T 67-68 HRC is rated for continuous service to 620°C (1,148 °F). It conducts heat at 21 W/m·K (12.1 BTU/hr·ft·°F), worse than 95% of steel grades. Thermal expansion is 11 µm/m·K (6.11 µin/in·°F).
Electrical2
M36 H&T 67-68 HRC has an electrical resistivity of 6.5×10⁻⁷ Ω·m.
Chemical & Environmental2
Corrosion resistance is poor (16/100), better than 79% of steel grades.
Sustainability4
Producing a kilogram of M36 H&T 67-68 HRC takes about 70 MJ of energy and emits 4.6 kg of CO₂ — more than 97% of steel grades. Typical recycled content is 30%.
Manufacturability8
M36 H&T 67-68 HRC's machinability is not recommended (5/100, 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 M36 H&T 67-68 HRC
Is M36 easy to machine?
Machine only in the annealed state with rigid setups, low speeds and carbide or coated tooling; hard-state work must be done by grinding (soft grade, friable Al2O3 or CBN wheels, plenty of coolant to avoid burn/cracks).
Can M36 be welded?
Essentially non-weldable for structure; edge repair only by preheated (500–550 °C) TIG or laser with matching HSS filler followed by immediate re-tempering.
Can M36 be formed, bent or molded?
Hot work at 1050–1150 °C with slow, controlled cooling and full anneal at 850–900 °C; no cold forming — hardening is 1200–1230 °C in vacuum/salt, quench, then triple temper 540–560 °C with a −70 °C or subzero step optional.
What surface finishes work on M36?
No native corrosion protection: use black oxide, steam temper, phosphate or PVD TiN/TiCN/TiAlN over a hardened, fine-ground surface; keep oiled in storage.
M36 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 | 0.8 – 0.9 | 0.85 |
| Mn | 0.15 – 0.4 | 0.28 |
| Si | 0.2 – 0.45 | 0.3 |
| Cr | 3.75 – 4.5 | 4.1 |
| Mo | 4.5 – 5.5 | 5 |
| W | 5.5 – 6.5 | 6 |
| V | 1.75 – 2.25 | 2 |
| Cocobalt addition gives the red-hardness advantage over M2/M35 | 7.75 – 8.75 | 8.25 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
M36 H&T 67-68 HRC — frequently asked
What is M36 H&T 67-68 HRC used for?
M36 H&T 67-68 HRC is typically used for motor laminations, distribution transformer cores, milling cutters and end mills, gear hobs and shaper cutters, twist drills and taps for tough alloys and form tools and broaches. In short: non-oriented electrical coil.
What is the yield strength of M36 H&T 67-68 HRC?
M36 H&T 67-68 HRC has a typical yield strength of 2,000 MPa (290 ksi) and a tensile strength of 2,100 MPa (305 ksi) — stronger than 100% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is M36 H&T 67-68 HRC easy to machine?
Not especially — machinability is rated not recommended (5/100, worse than 100% of steel grades). Machine only in the annealed state with rigid setups, low speeds and carbide or coated tooling; hard-state work must be done by grinding (soft grade, friable Al2O3 or CBN wheels, plenty of coolant to avoid burn/cracks).
Can M36 H&T 67-68 HRC be welded?
Not readily — weldability is rated not recommended (5/100). Essentially non-weldable for structure; edge repair only by preheated (500–550 °C) TIG or laser with matching HSS filler followed by immediate re-tempering.
What surface finishes work on M36 H&T 67-68 HRC?
No native corrosion protection: use black oxide, steam temper, phosphate or PVD TiN/TiCN/TiAlN over a hardened, fine-ground surface; keep oiled in storage.
Can M36 H&T 67-68 HRC be formed, bent or molded?
Hot work at 1050–1150 °C with slow, controlled cooling and full anneal at 850–900 °C; no cold forming — hardening is 1200–1230 °C in vacuum/salt, quench, then triple temper 540–560 °C with a −70 °C or subzero step optional.
What is the maximum service temperature of M36 H&T 67-68 HRC?
M36 H&T 67-68 HRC is rated for continuous use to about 620°C (1,148 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in M36 H&T 67-68 HRC?
Yes — M36 H&T 67-68 HRC is available for sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A600 — Standard Specification for Tool Steel High Speed — ASTM International (2016)
- 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)
- Cobalt high-speed steel bar datasheets (Erasteel / Böhler HSS grades) — Erasteel, voestalpine Böhler (2022)
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.