Steel Silicon Steel · temper · default condition
Steel Silicon Steel Annealed
Properties of the Annealed condition, compared with the other Silicon Steel tempers.
Default stocked condition: magnetic properties already developed, ready to punch and stack without further annealing.
What is Silicon Steel Annealed?
Silicon Steel Annealed is Silicon Steel in the Annealed temper — default stocked condition: magnetic properties already developed, ready to punch and stack without further annealing. Silicon Steel Annealed has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 80% of steel grades. Elongation at break is 20% and the elastic modulus is 200 GPa (29 Msi). Silicon Steel Annealed 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).
Advantages
- Forms and bends easily — 62/100, better than 78% of steel grades
Limitations
- 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
- Low strength — 320 MPa (46.4 ksi), worse than 80% of steel grades
- Difficult to machine — 38/100, worse than 80% of steel grades
Silicon Steel Annealed properties
Typical room-temperature values for Silicon Steel Annealed — 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 Annealed 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 Annealed has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 80% of steel grades. Elongation at break is 20% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
Silicon Steel Annealed 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 Annealed 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 Annealed 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 Annealed's machinability is fair (38/100, worse than 80% of steel grades); weldability fair (45/100); formability good (62/100).
Common Calculations5
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 Annealed
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 Annealed — frequently asked
What is Silicon Steel Annealed used for?
Silicon Steel Annealed 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 Annealed?
Silicon Steel Annealed has a typical yield strength of 320 MPa (46.4 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 80% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is Silicon Steel Annealed 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 Annealed 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 Annealed?
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 Annealed 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 Annealed?
Silicon Steel Annealed 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 Annealed?
Yes — Silicon Steel Annealed 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.