Steel 27W140
EN 27W140
27W140 is a 0.27 mm thin-gauge, high-silicon non-oriented electrical steel supplied as coil or slit strip with C-5 inorganic, C-6 semi-organic, self-bonding or bare surfaces, plus a stress-relief-annealed condition.
Reference datasheet — 27W140 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.
27W140 tempers and conditions
27W140 is supplied in one standard condition, SRA.
Supply forms, finishes and certifications
Ways 27W140 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
BARE | Uncoated (bare) fully processed strip | Surface finish |
FP-C6 | Fully processed, semi-organic (C-6 type) insulating coating | Surface finish |
SB | Self-bonding coating | Surface finish |
FP-C5Default | Fully processed, inorganic (C-5 type) insulating coating | Coating |
What is 27W140?
27W140 is a 0.27 mm thin-gauge, high-silicon non-oriented electrical steel supplied as coil or slit strip with C-5 inorganic, C-6 semi-organic, self-bonding or bare surfaces, plus a stress-relief-annealed condition. The thin gauge and high silicon content cut eddy-current loss, so it is specified for high-frequency and high-efficiency rotating machines, normally as precision-blanked stator and rotor laminations. Ductility is limited (10 % elongation, formability 45/100) and bare corrosion resistance is low (18/100), with the insulation limiting service to 200 °C. Where 0.27 mm gauge is not required, 0.35 mm grades such as 35A250 are the cheaper option. 27W140 has a density of 7.6 g/cm³ (0.275 lb/in³), lighter than 98% of steel grades. It melts at 1,500°C (2,732 °F). 27W140 has a yield strength of 370 MPa (53.7 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 70% of steel grades. Elongation at break is 10% and the elastic modulus is 190 GPa (27.6 Msi).
What is 27W140 used for?
- high-speed motors
- servo motors
- aerospace generators
Limitations
- Hard to polish — 40/100, worse than 96% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Poor heat conductor — 22 W/m·K (12.7 BTU/hr·ft·°F), worse than 93% of steel grades
- Low electrical conductivity — 2.9 % IACS, worse than 93% of steel grades
- Limited ductility — 10%, worse than 91% of steel grades
27W140 properties
Typical room-temperature values; bars are the position among steel grades.
Physical3
27W140 has a density of 7.6 g/cm³ (0.275 lb/in³), lighter than 98% of steel grades. It melts at 1,500°C (2,732 °F).
Mechanical11
27W140 has a yield strength of 370 MPa (53.7 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 70% of steel grades. Elongation at break is 10% and the elastic modulus is 190 GPa (27.6 Msi).
Thermal6
27W140 is rated for continuous service to 200°C (392 °F). It conducts heat at 22 W/m·K (12.7 BTU/hr·ft·°F), worse than 93% of steel grades. Thermal expansion is 11.8 µm/m·K (6.56 µin/in·°F).
Electrical3
27W140 conducts electricity at 2.9 % IACS, worse than 93% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (18/100), better than 83% of steel grades.
Sustainability4
Producing a kilogram of 27W140 takes about 34 MJ of energy and emits 2.5 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
27W140's machinability is poor (33/100, worse than 86% of steel grades); weldability fair (40/100); formability fair (45/100).
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. 27W140 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 27W140
Is 27W140 easy to machine?
Rarely machined — process by precision blanking/punching with carbide or PM tooling and tight clearance (~5 % of thickness); the abrasive high-Si strip wears dies fast and burrs must be minimal to keep core loss low.
Can 27W140 be welded?
Laser or TIG tacking of stacks is possible but weld beads short-circuit laminations and locally destroy magnetic performance; prefer interlocking, adhesive bonding or banding.
Can 27W140 be formed, bent or molded?
Good punchability but limited bendability at 0.27 mm high-Si; avoid tight bends, control coil set and de-burr, and stress-relief anneal at 750–820 °C in protective atmosphere if forming stresses are significant.
27W140 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 |
|---|---|---|
| Siraises resistivity, lowers eddy-current loss | 2.9 – 3.5 | 3.2 |
| Alfurther resistivity increase, deoxidiser | 0.3 – 1 | 0.6 |
| Mn | 0.1 – 0.5 | 0.25 |
| Ckept ultra-low to avoid magnetic ageing | ≤ 0.01 | 0 |
| S | ≤ 0.01 | 0 |
| P | ≤ 0.03 | 0.01 |
| N | ≤ 0 | 0 |
| Fe | balance |
What surface finishes work on 27W140?
Supplied pre-coated (inorganic C-5, semi-organic C-6 or self-bonding); no anodising. Bare strip must be oiled or varnished, and cut edges of any variant should be impregnated/varnished against rust.
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
How much does 27W140 cost?
27W140 is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
27W140 — frequently asked
What is 27W140 used for?
27W140 is typically used for high-speed motors, servo motors and aerospace generators. In short: thin-gauge low-loss lamination; built for high-frequency motors; self-bonding coating option.
What is the yield strength of 27W140?
27W140 has a typical yield strength of 370 MPa (53.7 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 70% of steel grades.
Is 27W140 easy to machine?
Not especially — machinability is rated poor (33/100, worse than 86% of steel grades). Rarely machined — process by precision blanking/punching with carbide or PM tooling and tight clearance (~5 % of thickness); the abrasive high-Si strip wears dies fast and burrs must be minimal to keep core loss low.
Can 27W140 be welded?
With care — weldability is rated fair (40/100). Laser or TIG tacking of stacks is possible but weld beads short-circuit laminations and locally destroy magnetic performance; prefer interlocking, adhesive bonding or banding.
What surface finishes work on 27W140?
Supplied pre-coated (inorganic C-5, semi-organic C-6 or self-bonding); no anodising. Bare strip must be oiled or varnished, and cut edges of any variant should be impregnated/varnished against rust.
Can 27W140 be formed, bent or molded?
Good punchability but limited bendability at 0.27 mm high-Si; avoid tight bends, control coil set and de-burr, and stress-relief anneal at 750–820 °C in protective atmosphere if forming stresses are significant.
What is the maximum service temperature of 27W140?
27W140 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 27W140 cost?
27W140 is a standard-cost steel ($$), cheaper than about 71% 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
- GB/T 2521.1 Cold-rolled non-oriented electrical steel strip (2016)
- IEC 60404-8-4 Cold-rolled non-oriented electrical steel sheet and strip — IEC (2013)
- ASTM A677 / A683 Non-oriented electrical steel, fully processed and semi-processed — ASTM (2020)
- ASM Handbook Vol.1 — Magnetically Soft Materials — ASM International (1990)
- Thin-gauge high-grade non-oriented electrical steel strip data (0.20–0.30 mm classes) — Baosteel / Shougang (2023)
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.