Steel 30Q140
EN 30Q140
30Q140 is a 0.30 mm conventional grain-oriented silicon steel whose Goss texture concentrates magnetic performance along the rolling direction; it is stocked as mill coil, cut-to-length sheet and stress-relief-annealed laminations.
Reference datasheet — 30Q140 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.
30Q140 tempers and conditions
30Q140 is supplied in one standard condition, SRA.
Supply forms, finishes and certifications
Ways 30Q140 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
CTL | Cut-to-length / slit laminations | Surface finish |
MILLDefault | Mill finish coil/strip | Surface finish |
What is 30Q140?
30Q140 is a 0.30 mm conventional grain-oriented silicon steel whose Goss texture concentrates magnetic performance along the rolling direction; it is stocked as mill coil, cut-to-length sheet and stress-relief-annealed laminations. Transformer builders choose it for low core loss in a fixed flux path, typically as mitre-cut stacked laminations or wound strip cores. The strip is brittle and strongly anisotropic (12 % elongation, formability 30/100), rated to 150 °C maximum service, and tolerates no deep drawing or transverse bending. 27Q120 is the next step down in gauge and loss. 30Q140 has a density of 7.65 g/cm³ (0.276 lb/in³), lighter than 97% of steel grades. It melts at 1,470°C (2,678 °F). 30Q140 has a yield strength of 310 MPa (45 ksi) and a tensile strength of 350 MPa (50.8 ksi) — weaker than 83% of steel grades. Elongation at break is 12% and the elastic modulus is 120 GPa (17.4 Msi).
What is 30Q140 used for?
- Distribution transformer cores
- Reactor and choke cores
- Wound strip transformer cores
- Mitre-cut stacked core laminations
- Cut-to-length core sheet
Limitations
- Low stiffness — 120 GPa (17.4 Msi), worse than 99% of steel grades
- Limited service temperature — 150°C (302 °F), worse than 99% of steel grades
- Hard to polish — 40/100, worse than 96% of steel grades
- Poor heat conductor — 23 W/m·K (13.3 BTU/hr·ft·°F), worse than 92% of steel grades
- High embodied carbon — 2.6 kg CO₂/kg, worse than 87% of steel grades
30Q140 properties
Typical room-temperature values; bars are the position among steel grades.
Physical3
30Q140 has a density of 7.65 g/cm³ (0.276 lb/in³), lighter than 97% of steel grades. It melts at 1,470°C (2,678 °F).
Mechanical9
30Q140 has a yield strength of 310 MPa (45 ksi) and a tensile strength of 350 MPa (50.8 ksi) — weaker than 83% of steel grades. Elongation at break is 12% and the elastic modulus is 120 GPa (17.4 Msi).
Thermal6
30Q140 is rated for continuous service to 150°C (302 °F). It conducts heat at 23 W/m·K (13.3 BTU/hr·ft·°F), worse than 92% of steel grades. Thermal expansion is 11.8 µm/m·K (6.56 µin/in·°F).
Electrical3
30Q140 conducts electricity at 3.6 % IACS, worse than 85% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (20/100), better than 87% of steel grades.
Sustainability4
Producing a kilogram of 30Q140 takes about 35 MJ of energy and emits 2.6 kg of CO₂ — more than 87% of steel grades. Typical recycled content is 15%.
Manufacturability7
30Q140's machinability is fair (35/100, worse than 84% of steel grades); weldability poor (30/100); formability poor (30/100).
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. 30Q140 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 30Q140
Is 30Q140 easy to machine?
Work is precision shearing, blanking and slitting; dies need carbide or coated edges and a clearance of about 5–8 % of thickness to limit burr height and the width of the shear-stressed zone.
Can 30Q140 be welded?
Avoid welding where possible; hold cores with clamping frames or banding, and if spot or TIG tacking is unavoidable, follow with a full stress-relief anneal — welds still raise loss locally.
Can 30Q140 be formed, bent or molded?
Suitable only for flat blanking and large-radius winding of wound cores; transverse bending cracks the strip. A stress-relief anneal at 800–840 °C in protective atmosphere after forming restores magnetic properties.
30Q140 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 |
|---|---|---|
| Sikey element for Goss texture and high resistivity | 2.9 – 3.4 | 3.1 |
| Cresidual after decarburization annealing; lower means less aging | ≤ 0.01 | 0 |
| Mn | 0.03 – 0.2 | 0.1 |
| SMnS inhibitor residue | ≤ 0.01 | 0.01 |
| P | ≤ 0.03 | 0.02 |
| AlAlN inhibitor | ≤ 0.04 | 0.02 |
| N | ≤ 0.01 | 0.01 |
| Cuused as inhibitor element in some processes | ≤ 0.6 | 0.2 |
| Fe | balance |
What surface finishes work on 30Q140?
Delivered with a C-5 type phosphate inorganic insulating coating and normally needs no further painting; sheared bare edges can be varnished or oiled to prevent 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 30Q140 cost?
30Q140 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.
30Q140 — frequently asked
What is 30Q140 used for?
30Q140 is typically used for distribution transformer cores, reactor and choke cores, wound strip transformer cores, mitre-cut stacked core laminations and cut-to-length core sheet. In short: baseline grain-oriented transformer steel; low loss along rolling direction; not for formed parts.
What is the yield strength of 30Q140?
30Q140 has a typical yield strength of 310 MPa (45 ksi) and a tensile strength of 350 MPa (50.8 ksi) — weaker than 83% of steel grades.
Is 30Q140 easy to machine?
Not especially — machinability is rated fair (35/100, worse than 84% of steel grades). Work is precision shearing, blanking and slitting; dies need carbide or coated edges and a clearance of about 5–8 % of thickness to limit burr height and the width of the shear-stressed zone.
Can 30Q140 be welded?
Not readily — weldability is rated poor (30/100). Avoid welding where possible; hold cores with clamping frames or banding, and if spot or TIG tacking is unavoidable, follow with a full stress-relief anneal — welds still raise loss locally.
What surface finishes work on 30Q140?
Delivered with a C-5 type phosphate inorganic insulating coating and normally needs no further painting; sheared bare edges can be varnished or oiled to prevent rust.
Can 30Q140 be formed, bent or molded?
Suitable only for flat blanking and large-radius winding of wound cores; transverse bending cracks the strip. A stress-relief anneal at 800–840 °C in protective atmosphere after forming restores magnetic properties.
What is the maximum service temperature of 30Q140?
30Q140 is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 30Q140 cost?
30Q140 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
- IEC 60404-8-7 Magnetic materials — grain-oriented steel sheet and strip — IEC (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys (Fe-Si electrical steels) — 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.