Steel M47
AISI/SAE M47 · UNS T11347
M47 covers two materials that share the designation: the lowest-cost semi-processed non-oriented electrical sheet in the M-series under ASTM A683, specified where magnetic performance is secondary to price, and M47 high-speed steel (UNS T11347), whose annealed values are listed here — 570 MPa yield, 890 MPa tensile, 255 HB (25 HRC), 218 GPa modulus, 24 W/m·K.
Reference datasheet — M47 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the ANN condition
M47 tempers and conditions
M47 is supplied in 5 conditions, soft to hard. ANN is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Electrical sheet after quality-development anneal (customer full anneal) | Condition in which magnetic properties are actually realised — soft, grain-grown laminations after the ~790 °C decarburising/annealing cycle. | 210 | 340 | 33 | 100 HB | — |
Semi-processed non-oriented electrical sheet | Lowest-cost lamination sheet for small motors and ballasts, supplied hard-rolled for punching and annealed by the laminator afterwards. | 320 | 430 | 22 | 125 HB | 7.8 % IACS |
ANNDefault Annealed | Standard mill-supplied condition for machining or grinding tool blanks before hardening. | 570 | 890 | 18 | 25 HRC | 24 W/m·K |
Hardened & tempered to maximum hardness | Top-hardness setting (higher austenitizing temperature) for finishing cutters on abrasive materials where toughness can be sacrificed. | 2,000 | 2,100 | 0.5 | 68 HRC | 2.8 % IACS |
Hardened & triple tempered | Normal service condition: austenitize ~1190–1210 °C, quench, temper 3 × 1 h at ~540–550 °C for high red hardness. | 2,300 | 1 | 66 HRC | 21 W/m·K |
Supply forms, finishes and certifications
Ways M47 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
HT+PVD | Hardened & tempered + PVD coated | Surface finish |
What is M47?
M47 covers two materials that share the designation: the lowest-cost semi-processed non-oriented electrical sheet in the M-series under ASTM A683, specified where magnetic performance is secondary to price, and M47 high-speed steel (UNS T11347), whose annealed values are listed here — 570 MPa yield, 890 MPa tensile, 255 HB (25 HRC), 218 GPa modulus, 24 W/m·K. The tool grade is cut soft and hardened to 65–68 HRC; the sheet grade is punched cold and annealed. Machinability is about 30 % of AISI 1212 and only in the annealed state, maximum service temperature is 400 °C, and corrosion resistance is low. M47 has a density of 8.03 g/cm³ (0.29 lb/in³), heavier than 96% of steel grades. It melts at 1,250°C (2,282 °F). M47 has a yield strength of 570 MPa (82.7 ksi) and a tensile strength of 890 MPa (129 ksi) — stronger than 74% of steel grades. Elongation at break is 18% and the elastic modulus is 218 GPa (31.6 Msi).
What is M47 used for?
- low-cost fractional-hp motors
- toys
- small solenoids
Advantages
- Polishes to a fine finish — 75/100, better than 94% of steel grades
Limitations
- Low fracture toughness — 35 MPa·√m (31.9 ksi·√in), worse than 94% of steel grades
- High embodied carbon — 3.6 kg CO₂/kg, worse than 94% of steel grades
- Poor heat conductor — 24 W/m·K (13.9 BTU/hr·ft·°F), worse than 90% of steel grades
- Difficult to machine — 30/100, worse than 89% of steel grades
- Low electrical conductivity — 3.2 % IACS, worse than 87% of steel grades
M47 properties
Typical room-temperature values for M47-ANN; bars are the position among steel grades.
Physical3
M47 has a density of 8.03 g/cm³ (0.29 lb/in³), heavier than 96% of steel grades. It melts at 1,250°C (2,282 °F).
Mechanical15
M47 has a yield strength of 570 MPa (82.7 ksi) and a tensile strength of 890 MPa (129 ksi) — stronger than 74% of steel grades. Elongation at break is 18% and the elastic modulus is 218 GPa (31.6 Msi).
Thermal6
M47 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 11 µm/m·K (6.11 µin/in·°F).
Electrical3
M47 conducts electricity at 3.2 % IACS, worse than 87% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (15/100), better than 75% of steel grades.
Sustainability4
Producing a kilogram of M47 takes about 58 MJ of energy and emits 3.6 kg of CO₂ — more than 95% of steel grades. Typical recycled content is 35%.
Manufacturability8
M47's machinability is poor (30/100, worse than 89% of steel grades); weldability poor (20/100); formability poor (15/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. M47 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with M47
Is M47 easy to machine?
Machine only in the annealed state (≈255 HB, ~30 % of AISI 1212) with rigid setups and cobalt/carbide tooling; after hardening it is a grind-only material — use soft-grade CBN or SG alumina wheels and copious coolant to avoid grinding burn.
Can M47 be welded?
Not a structural weld metal; repair welding of tool edges only, with 500–550 °C preheat, matching Co-HSS or Ni-based filler and an immediate re-temper.
Can M47 be formed, bent or molded?
Hot work between about 1100 and 900 °C with slow furnace cooling; no meaningful cold formability — the A683 electrical-sheet variant, by contrast, is punched cold and then annealed.
M47 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 |
|---|---|---|
| Chigh-speed tool steel M47, ASTM A600 / UNS T11347 | 1.05 – 1.15 | 1.1 |
| Mn | 0.15 – 0.4 | 0.3 |
| Si | 0.2 – 0.65 | 0.4 |
| Cr | 3.5 – 4.25 | 3.85 |
| Mo | 9.25 – 10 | 9.6 |
| W | 1.15 – 1.85 | 1.5 |
| V | 1.15 – 1.35 | 1.25 |
| Co | 4.75 – 5.25 | 5 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| FeBalance. NOTE: the ASTM A683 'M47' electrical sheet of the same name is an unrelated low-carbon Fe–Si sheet (C ≤ 0.03, Si+Al ≈ 0.5–1.5 %, Mn ≈ 0.3), specified by core loss rather than chemistry. | balance |
What surface finishes work on M47?
Cannot be anodized; standard finishes are steam/black oxide, nitriding (thin case, watch edge brittleness) or PVD TiN/TiAlN applied below the 540 °C temper, plus oil film for storage.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel M47 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- T11347
How much does M47 cost?
M47 is a high-cost steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
M47 — frequently asked
What is M47 used for?
M47 is typically used for low-cost fractional-hp motors, toys and small solenoids. In short: cheapest M-series lamination grade; price over magnetic performance; grind-only when hardened.
What is the yield strength of M47?
M47 has a typical yield strength of 570 MPa (82.7 ksi) and a tensile strength of 890 MPa (129 ksi) — stronger than 74% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is M47 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 89% of steel grades). Machine only in the annealed state (≈255 HB, ~30 % of AISI 1212) with rigid setups and cobalt/carbide tooling; after hardening it is a grind-only material — use soft-grade CBN or SG alumina wheels and copious coolant to avoid grinding burn.
Can M47 be welded?
Not readily — weldability is rated poor (20/100). Not a structural weld metal; repair welding of tool edges only, with 500–550 °C preheat, matching Co-HSS or Ni-based filler and an immediate re-temper.
What surface finishes work on M47?
Cannot be anodized; standard finishes are steam/black oxide, nitriding (thin case, watch edge brittleness) or PVD TiN/TiAlN applied below the 540 °C temper, plus oil film for storage.
Can M47 be formed, bent or molded?
Hot work between about 1100 and 900 °C with slow furnace cooling; no meaningful cold formability — the A683 electrical-sheet variant, by contrast, is punched cold and then annealed.
What is the maximum service temperature of M47?
M47 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.
What is the difference between M47-ANN and M47 HT-68?
ANN is the default condition — standard mill-supplied condition for machining or grinding tool blanks before hardening. HT-68: top-hardness setting (higher austenitizing temperature) for finishing cutters on abrasive materials where toughness can be sacrificed. Yield strength is 570 MPa in ANN versus 2,000 MPa in HT-68.
How much does M47 cost?
M47 is a high-cost steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM A600 — Standard Specification for Tool Steel High Speed — ASTM International (2016)
- ASTM A683 — Standard Specification for Nonoriented Electrical Steel, Semiprocessed Types — ASTM International (2019)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 16: Machining — ASM International (1989)
- Tool Steels, 5th ed. (Roberts, Krauss, Kennedy) — ASM International (1998)
- SAE J438 / UNS T11347 designation data — SAE International (2017)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.