Steel B50A470
JIS 50A470
B50A470 (JIS 50A470, near AISI M19) is a general-purpose non-oriented silicon electrical steel strip in 0.50 mm gauge, supplied fully annealed, stress-relief annealed or skin passed with a thin insulating coating.
Values for the Final Annealed condition
B50A470 tempers and conditions
B50A470 is supplied in 3 conditions, soft to hard. Final Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Stress-relief annealed after blanking | Pick when punching/edge stresses must be recovered: core loss drops and permeability rises by roughly 5–15 %, at the cost of softer, more distortion-prone laminations. | 255 | 400 | 34 | 138 HB | 4.3 % IACS |
Final AnnealedDefault fully processed, insulation coated (as supplied) | Standard as-shipped fully-processed condition: stamp laminations and stack directly, guaranteed P1.5/50 ≤ 4.70 W/kg at 0.50 mm. | 305 | 450 | 30 | 157 HB | 4.3 % IACS |
lightly cold-worked flatness pass | Occasionally supplied for improved flatness and punch burr control on high-speed presses; slightly higher strength and marginally higher core loss than the plain annealed coil. | 350 | 480 | 24 | 171 HB | 4.3 % IACS |
What is B50A470?
B50A470 (JIS 50A470, near AISI M19) is a general-purpose non-oriented silicon electrical steel strip in 0.50 mm gauge, supplied fully annealed, stress-relief annealed or skin passed with a thin insulating coating. It is used for motor stator and rotor laminations and small transformer cores where core loss, permeability, punchability and cost must be balanced; mechanical properties are 305 MPa yield, 450 MPa tensile and 30 % elongation, with service to 200 °C and a formability score of 72. Core loss is higher than thinner or higher-silicon grades, so move to 0.35 mm material for high-frequency or high-efficiency machines. B50A470 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 95% of steel grades. It melts at 1,500°C (2,732 °F). B50A470 has a yield strength of 305 MPa (44.2 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 84% of steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
What is B50A470 used for?
- Motor stator and rotor laminations
- Distribution transformer cores
- Generator and alternator laminations
- Pump and fan motor cores
- Reactor and choke cores
- Solenoid and relay cores
- Small E-I transformer laminations
Advantages
- Ductile — tolerates forming and impact — 30%, better than 93% of steel grades
- Forms and bends easily — 72/100, better than 88% of steel grades
Limitations
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Poor heat conductor — 28 W/m·K (16.2 BTU/hr·ft·°F), worse than 85% of steel grades
- Low strength — 305 MPa (44.2 ksi), worse than 84% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
- Low electrical conductivity — 4.3 % IACS, worse than 82% of steel grades
B50A470 properties
Typical room-temperature values for B50A470-Final Annealed; bars are the position among steel grades.
Physical3
B50A470 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 95% of steel grades. It melts at 1,500°C (2,732 °F).
Mechanical14
B50A470 has a yield strength of 305 MPa (44.2 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 84% of steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
B50A470 is rated for continuous service to 200°C (392 °F). It conducts heat at 28 W/m·K (16.2 BTU/hr·ft·°F), worse than 85% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
B50A470 conducts electricity at 4.3 % IACS, worse than 82% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (15/100), better than 75% of steel grades.
Sustainability4
Producing a kilogram of B50A470 takes about 32 MJ of energy and emits 2.4 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 20%.
Manufacturability6
B50A470's machinability is good (55/100, better than 62% of steel grades); weldability fair (50/100); formability very good (72/100).
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. B50A470 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with B50A470
Is B50A470 easy to machine?
Primarily progressive-die punched or laser/wire cut; keep punch clearance ~5–8 % of thickness and tools sharp, since burrs and cut-edge damage directly raise core loss.
Can B50A470 be welded?
Laser or micro-TIG tack welding of stacks is feasible but each weld bridges laminations and increases eddy-current loss — prefer interlocking, bonding or cleats.
Can B50A470 be formed, bent or molded?
Excellent blanking and light bending at 0.50 mm; avoid heavy cold work near tooth roots, and stress-relief anneal at 750–800 °C in a neutral, decarburising-free atmosphere if magnetics are critical.
Manufacturability
The process limits FabDigit applies to B50A470. Every B50A470 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
Sheet metal
| Formability | Better72 / 100 |
|---|---|
| Weldability | Poor50 / 100 |
| Bendable | Yes |
B50A470 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 |
|---|---|---|
| Cultra-low to avoid magnetic ageing | ≤ 0.01 | 0 |
| Siraises resistivity, lowers eddy-current loss | 1.4 – 2.3 | 1.9 |
| Al | 0.2 – 0.6 | 0.4 |
| Mn | 0.15 – 0.5 | 0.3 |
| P | ≤ 0.06 | 0.02 |
| S | ≤ 0.01 | 0 |
| N | ≤ 0 | 0 |
| Fe | balance |
What surface finishes work on B50A470?
Supplied with a thin semi-organic/inorganic insulating coating (C5/C6 type) that also acts as a punching lubricant; do not shot blast or pickle, and mask coating loss areas from corrosion in humid 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).
Plating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel B50A470 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- JIS
- 50A470
- Similar grades
- M19
How much does B50A470 cost?
B50A470 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.
B50A470 — frequently asked
What is B50A470 used for?
B50A470 is typically used for motor stator and rotor laminations, distribution transformer cores, generator and alternator laminations, pump and fan motor cores, reactor and choke cores and solenoid and relay cores. In short: workhorse electrical coil.
What is the yield strength of B50A470?
B50A470 has a typical yield strength of 305 MPa (44.2 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 84% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is B50A470 easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Primarily progressive-die punched or laser/wire cut; keep punch clearance ~5–8 % of thickness and tools sharp, since burrs and cut-edge damage directly raise core loss.
Can B50A470 be welded?
With care — weldability is rated fair (50/100). Laser or micro-TIG tack welding of stacks is feasible but each weld bridges laminations and increases eddy-current loss — prefer interlocking, bonding or cleats.
What surface finishes work on B50A470?
Supplied with a thin semi-organic/inorganic insulating coating (C5/C6 type) that also acts as a punching lubricant; do not shot blast or pickle, and mask coating loss areas from corrosion in humid storage.
Can B50A470 be formed, bent or molded?
Excellent blanking and light bending at 0.50 mm; avoid heavy cold work near tooth roots, and stress-relief anneal at 750–800 °C in a neutral, decarburising-free atmosphere if magnetics are critical.
What is the maximum service temperature of B50A470?
B50A470 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.
What is the difference between B50A470 Final Annealed and B50A470-SRA?
Final Annealed is the default condition — standard as-shipped fully-processed condition: stamp laminations and stack directly, guaranteed P1.5/50 ≤ 4.70 W/kg at 0.50 mm. SRA: pick when punching/edge stresses must be recovered: core loss drops and permeability rises by roughly 5–15 %, at the cost of softer, more distortion-prone laminations. Yield strength is 305 MPa in Final Annealed versus 255 MPa in SRA.
How much does B50A470 cost?
B50A470 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.
Can FabDigit make parts in B50A470?
Yes — B50A470 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
- JIS C 2552 — Non-oriented electrical steel strip — JSA (2019)
- EN 10106 — Cold rolled non-oriented electrical steel strip and sheet delivered in the fully processed state — CEN (2015)
- Baosteel Electrical Steel Product Catalogue (B50A series) — Baoshan Iron & Steel (2022)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys (magnetically soft materials) — ASM International (1990)
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.