Steel Silicon Steel · grade
Steel Silicon Steel CRGO
Properties of the CRGO condition, compared with the other Silicon Steel tempers.
Use for transformer and reactor cores where flux runs along the rolling direction; lowest loss but strongly anisotropic.
What is Silicon Steel CRGO?
Silicon Steel CRGO is Silicon Steel in the CRGO grade — use for transformer and reactor cores where flux runs along the rolling direction; lowest loss but strongly anisotropic. Silicon Steel CRGO has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 380 MPa (55.1 ksi) — weaker than 80% of steel grades. Elongation at break is 8% and the elastic modulus is 130 GPa (18.9 Msi). Silicon Steel CRGO has a density of 7.65 g/cm³ (0.276 lb/in³), lighter than 97% of steel grades. It melts at 1,500°C (2,732 °F). Annealed is the default condition FabDigit quotes; CRGO is available on request or by drawing note.
Limitations
- Low stiffness — 130 GPa (18.9 Msi), worse than 99% of steel grades
- Limited ductility — 8%, worse than 95% 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 — 3.6 % IACS, worse than 85% of steel grades
Silicon Steel CRGO properties
Typical room-temperature values for Silicon Steel CRGO — 10 properties are specific to this condition; the rest are grade-level values shared by every Silicon Steel temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
Silicon Steel CRGO has a density of 7.65 g/cm³ (0.276 lb/in³), lighter than 97% of steel grades. It melts at 1,500°C (2,732 °F).
Mechanical12
Silicon Steel CRGO has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 380 MPa (55.1 ksi) — weaker than 80% of steel grades. Elongation at break is 8% and the elastic modulus is 130 GPa (18.9 Msi).
Thermal6
Silicon Steel CRGO 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 12 µm/m·K (6.67 µin/in·°F).
Electrical3
Silicon Steel CRGO conducts electricity at 3.6 % IACS, worse than 85% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (13/100), better than 66% of steel grades.
Sustainability4
Producing a kilogram of Silicon Steel CRGO takes about 34 MJ of energy and emits 2.3 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
Silicon Steel CRGO's machinability is fair (38/100, worse than 80% of steel grades); weldability fair (45/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other Silicon Steel tempers and conditions
Silicon Steel is also supplied in 7 other conditions. The full side-by-side table is on the Silicon Steel overview.
- AnnealedDefaultDefault stocked condition: magnetic properties already developed, ready to punch and stack without further annealing.320 MPa yield · 170 HB
- Cold RolledChoose when high stiffness/strength and tight thickness tolerance matter and the part will be annealed later, or for non-magnetic structural use of the strip.580 MPa yield · 222 HB
- CRNGOStandard motor/generator lamination material: isotropic in-plane magnetics, coated for interlaminar insulation.330 MPa yield · 180 HV
- Hot RolledLegacy/low-cost option for thick laminations, small transformers and pole pieces where loss targets are loose.330 MPa yield · 160 HB
- CRGOUse for transformer and reactor cores where flux runs along the rolling direction; lowest loss but strongly anisotropic.320 MPa yield · 190 HV
- Hi-B CRGOPremium transformer grade: sharper Goss texture plus tensile coating/laser scribing for the lowest core loss at high induction.315 MPa yield · 190 HV
Working with Silicon Steel CRGO
Is Silicon Steel easy to machine?
Silicon makes chips abrasive and burr-prone — use sharp carbide or coated HSS, generous flood coolant, and expect fast tool wear; thin strip is normally punched or laser/EDM cut rather than machined.
Can Silicon Steel be welded?
Weldable by TIG/laser/resistance after stripping core-plate, but the HAZ grows coarse or oxidized and raises core loss — keep welds off the flux path or stress-relief anneal afterwards.
Can Silicon Steel be formed, bent or molded?
Fully processed strip stamps and bends well with sharp, well-maintained tooling (clearance ~5 % of thickness); high-Si and grain-oriented grades are notch-sensitive and crack on tight bends.
What surface finishes work on Silicon Steel?
Normally used as supplied with inorganic/organic core-plate (C-3/C-5/C-6) or phosphate insulation; bare edges need varnish, oil or paint since the steel rusts readily. Not anodizable.
Silicon Steel 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 |
|---|---|---|
| Si≈0.5–1.5 % low grades, 2.5–3.5 % high grades and all grain-oriented | 0.5 – 3.5 | 3 |
| Cdecarburized to <0.005 % in fully processed strip | 0 – 0.03 | 0 |
| Mn | 0.05 – 0.5 | 0.2 |
| Alresistivity/grain-growth control in NGO; AlN inhibitor in GO | 0.05 – 0.6 | 0.3 |
| P | ≤ 0.06 | 0.02 |
| SMnS inhibitor in conventional GO | ≤ 0.02 | 0.01 |
| N | ≤ 0.01 | 0 |
| Snoptional grain-boundary segregant in some GO grades | ≤ 0.1 | — |
| Fe | balance | — |
Silicon Steel CRGO — frequently asked
What is Silicon Steel CRGO used for?
Silicon Steel CRGO is typically used for transformer cores, electric motor stator and rotor laminations, generator and alternator cores, inductor and choke cores, current and instrument transformer cores and solenoid and relay armatures. In short: superior magnetic properties.
What is the yield strength of Silicon Steel CRGO?
Silicon Steel CRGO has a typical yield strength of 320 MPa (46.4 ksi) and a tensile strength of 380 MPa (55.1 ksi) — weaker than 80% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is Silicon Steel CRGO easy to machine?
Not especially — machinability is rated fair (38/100, worse than 80% of steel grades). Silicon makes chips abrasive and burr-prone — use sharp carbide or coated HSS, generous flood coolant, and expect fast tool wear; thin strip is normally punched or laser/EDM cut rather than machined.
Can Silicon Steel CRGO be welded?
With care — weldability is rated fair (45/100). Weldable by TIG/laser/resistance after stripping core-plate, but the HAZ grows coarse or oxidized and raises core loss — keep welds off the flux path or stress-relief anneal afterwards.
What surface finishes work on Silicon Steel CRGO?
Normally used as supplied with inorganic/organic core-plate (C-3/C-5/C-6) or phosphate insulation; bare edges need varnish, oil or paint since the steel rusts readily. Not anodizable.
Can Silicon Steel CRGO be formed, bent or molded?
Fully processed strip stamps and bends well with sharp, well-maintained tooling (clearance ~5 % of thickness); high-Si and grain-oriented grades are notch-sensitive and crack on tight bends.
What is the maximum service temperature of Silicon Steel CRGO?
Silicon Steel CRGO 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 Silicon Steel Annealed and Silicon Steel-SRA?
Annealed is the default condition — default stocked condition: magnetic properties already developed, ready to punch and stack without further annealing. SRA: apply after punching, bending or slitting to recover permeability and remove the loss penalty from cut edges and burrs. Yield strength is 320 MPa in Annealed versus 300 MPa in SRA.
Can FabDigit make parts in Silicon Steel CRGO?
Yes — Silicon Steel CRGO is available for sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A677 — Nonoriented Electrical Steel Fully Processed Types — ASTM (2020)
- ASTM A683 — Nonoriented Electrical Steel Semiprocessed Types — ASTM (2019)
- ASTM A876 — Flat-Rolled, Grain-Oriented, Silicon-Iron, Fully Processed Types — ASTM (2019)
- IEC 60404-8-4 — Cold-rolled non-oriented electrical steel sheet and strip — IEC (2013)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels (Soft Magnetic Materials) — ASM International (1990)
- Selection of Electrical Steels for Magnetic Cores — AK Steel / Cleveland-Cliffs (2019)
- Electrical steel product catalogue (NGO / GO / Hi-B) — Baosteel (2023)
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.