Steel CRGO · temper · default condition
Steel CRGO Annealed
Properties of the Annealed condition, compared with the other CRGO tempers.
Standard commercial condition: magnetic properties and coating are final, use as-slit/as-punched with only a light stress-relief anneal after cutting.
What is CRGO Annealed?
CRGO Annealed is CRGO in the Annealed temper — standard commercial condition: magnetic properties and coating are final, use as-slit/as-punched with only a light stress-relief anneal after cutting. CRGO Annealed has a yield strength of 305 MPa (44.2 ksi) and a tensile strength of 345 MPa (50 ksi) — weaker than 84% of steel grades. Elongation at break is 10% and the elastic modulus is 125 GPa (18.1 Msi). CRGO Annealed has a density of 7.65 g/cm³ (0.276 lb/in³), lighter than 97% of steel grades. It melts at 1,480°C (2,696 °F).
Limitations
- Low stiffness — 125 GPa (18.1 Msi), worse than 99% 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
- Limited ductility — 10%, worse than 91% of steel grades
- High embodied carbon — 2.6 kg CO₂/kg, worse than 86% of steel grades
CRGO Annealed properties
Typical room-temperature values for CRGO Annealed — 8 properties are specific to this condition; the rest are grade-level values shared by every CRGO temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
CRGO Annealed has a density of 7.65 g/cm³ (0.276 lb/in³), lighter than 97% of steel grades. It melts at 1,480°C (2,696 °F).
Mechanical12
CRGO Annealed has a yield strength of 305 MPa (44.2 ksi) and a tensile strength of 345 MPa (50 ksi) — weaker than 84% of steel grades. Elongation at break is 10% and the elastic modulus is 125 GPa (18.1 Msi).
Thermal6
CRGO 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
CRGO Annealed conducts electricity at 3.6 % IACS, worse than 85% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (18/100), better than 83% of steel grades.
Sustainability4
Producing a kilogram of CRGO Annealed takes about 40 MJ of energy and emits 2.6 kg of CO₂ — more than 91% of steel grades. Typical recycled content is 15%.
Manufacturability7
CRGO Annealed's machinability is fair (45/100, worse than 65% 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.
Other CRGO tempers and conditions
CRGO is also supplied in 3 other conditions. The full side-by-side table is on the CRGO overview.
- AnnealedDefaultStandard commercial condition: magnetic properties and coating are final, use as-slit/as-punched with only a light stress-relief anneal after cutting.305 MPa yield · 180 HV
- Cold RolledSemi-finished mill condition (or customer-supplied hard strip): high strength and hardness but poor magnetic properties — must be decarburized/high-temperature annealed before use as a core.570 MPa yield · 26 HRC
Working with CRGO Annealed
Is CRGO easy to machine?
Normally slit, punched, guillotined or laser/EDM cut rather than machined; the ceramic-like coating and Si content are abrasive, so use carbide/coated tooling and sharp, well-maintained dies to avoid burrs that short laminations.
Can CRGO be welded?
TIG/laser welding is possible for core clamping tabs but locally destroys texture, coating and interlaminar insulation and raises core loss — keep welds off the flux path.
Can CRGO be formed, bent or molded?
Formability is limited and highly anisotropic; restrict to shearing, slitting and gentle radii along the rolling direction, then stress-relief anneal (~800 °C, decarburizing-free atmosphere) to recover punching-induced loss.
What surface finishes work on CRGO?
Supplied ready-coated (C-5/C-6 phosphate-type insulating layer); do not pickle or blast; protect cut edges with varnish, oil or core-plate paint against rust.
CRGO 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 – 3.4 | 3.1 |
| Cafter decarburization anneal | ≤ 0.01 | 0 |
| Mn | 0.03 – 0.2 | 0.1 |
| SMnS inhibitor in CGO route | ≤ 0.01 | 0 |
| P | ≤ 0.03 | 0.01 |
| AlAlN inhibitor in HiB route | ≤ 0.04 | 0.03 |
| N | ≤ 0.01 | 0.01 |
| Cuinhibitor addition in some HiB routes | ≤ 0.6 | 0.1 |
| Fe | balance | — |
CRGO Annealed — frequently asked
What is CRGO Annealed used for?
CRGO Annealed is typically used for power transformer cores, distribution transformer cores, wound and stacked core laminations, reactor and choke cores, instrument and current transformer cores and large rotating-machine laminations. In short: grain-oriented electrical coil.
What is the yield strength of CRGO Annealed?
CRGO Annealed has a typical yield strength of 305 MPa (44.2 ksi) and a tensile strength of 345 MPa (50 ksi) — weaker than 84% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is CRGO Annealed easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Normally slit, punched, guillotined or laser/EDM cut rather than machined; the ceramic-like coating and Si content are abrasive, so use carbide/coated tooling and sharp, well-maintained dies to avoid burrs that short laminations.
Can CRGO Annealed be welded?
Not readily — weldability is rated poor (30/100). TIG/laser welding is possible for core clamping tabs but locally destroys texture, coating and interlaminar insulation and raises core loss — keep welds off the flux path.
What surface finishes work on CRGO Annealed?
Supplied ready-coated (C-5/C-6 phosphate-type insulating layer); do not pickle or blast; protect cut edges with varnish, oil or core-plate paint against rust.
Can CRGO Annealed be formed, bent or molded?
Formability is limited and highly anisotropic; restrict to shearing, slitting and gentle radii along the rolling direction, then stress-relief anneal (~800 °C, decarburizing-free atmosphere) to recover punching-induced loss.
What is the maximum service temperature of CRGO Annealed?
CRGO 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 CRGO Annealed and CRGO-HiB?
Annealed is the default condition — standard commercial condition: magnetic properties and coating are final, use as-slit/as-punched with only a light stress-relief anneal after cutting. HiB: choose for lowest core loss and highest induction (e.g. 30Q120/27QG100 class) in energy-efficient distribution and power transformers; mechanical properties as annealed. Yield strength is 305 MPa in Annealed versus 300 MPa in HiB.
Can FabDigit make parts in CRGO Annealed?
Yes — CRGO Annealed is available for sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A876 — Flat-Rolled, Grain-Oriented, Silicon-Iron, Electrical Steel, Fully Processed Types — ASTM International (2018)
- IEC 60404-8-7 — Magnetic materials: grain-oriented steel sheet and strip — IEC (2020)
- ASM Handbook Vol. 2 — Properties of Magnetically Soft Materials — ASM International (1990)
- Grain-oriented electrical steel (TRAN-COR H / conventional GO) product data — Cleveland-Cliffs (AK Steel) (2022)
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.