Steel SGHC-R
Grade
JIS SGHC · EN DX51D
R = regular (normal) spangle surface finish
Default as-solidified large spangle; cheapest, for unpainted structural use.
Values for the R condition
Other SGHC tempers and conditions
SGHC is listed in 5 conditions; see the grade overview at SGHC.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
RThis page Regular (normal) spangle surface finish | Default as-solidified large spangle; cheapest, for unpainted structural use. | 240 | 310 | 32 | 95 HB | 11 % IACS |
Chromate (or Cr-free) passivated surface treatment | Passivated to suppress white rust during storage and shipping. | 240 | 310 | 32 | 95 HB | 11 % IACS |
Annealed | Thin protective oil film for stacking/stamping; must be degreased before painting. | 240 | 310 | 32 | 95 HB | 11 % IACS |
Thermomechanically controlled processed | Fine spangle for a more uniform surface before painting or for visible panels. | 245 | 315 | 31 | 97 HB | 11 % IACS |
Skin-passed (temper-rolled) condition | Temper-rolled to remove yield-point elongation and stretcher strains before forming. | 255 | 320 | 30 | 100 HB | 11 % IACS |
What is SGHC-R?
SGHC-R is SGHC in the R grade — default as-solidified large spangle; cheapest, for unpainted structural use. SGHC-R has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 310 MPa (45 ksi) — weaker than 96% of steel grades. Elongation at break is 32% and the elastic modulus is 205 GPa (29.7 Msi). SGHC-R has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,495°C (2,723 °F).
Advantages
- Conducts heat well — 52 W/m·K (30 BTU/hr·ft·°F), better than 98% of steel grades
- High electrical conductivity — 11 % IACS, better than 98% of steel grades
- Good corrosion resistance — 40/100, better than 98% of steel grades
- Ductile — tolerates forming and impact — 32%, better than 95% of steel grades
- Forms and bends easily — 78/100, better than 91% of steel grades
Limitations
- Hard to polish — 20/100, worse than 100% of steel grades
- Low strength — 240 MPa (34.8 ksi), worse than 96% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
SGHC-R properties
Typical room-temperature values for SGHC-R; 21 are specific to this condition. Other listed values are SGHC reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
SGHC-R has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,495°C (2,723 °F).
Mechanical14
SGHC-R has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 310 MPa (45 ksi) — weaker than 96% of steel grades. Elongation at break is 32% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
SGHC-R is rated for continuous service to 200°C (392 °F). It conducts heat at 52 W/m·K (30 BTU/hr·ft·°F), better than 98% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
SGHC-R conducts electricity at 11 % IACS, better than 98% of steel grades.
Chemical & Environmental3
Corrosion resistance is fair (40/100), better than 98% of steel grades.
Sustainability4
Producing a kilogram of SGHC-R takes about 28 MJ of energy and emits 2.4 kg of CO₂ — less than 56% of steel grades. Typical recycled content is 25%.
Manufacturability7
SGHC-R's machinability is good (62/100, better than 89% of steel grades); weldability good (60/100); formability very good (78/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with SGHC-R
Is SGHC easy to machine?
Soft and gummy — shear, punch or laser-cut rather than machine; use sharp tooling and keep zinc dust/fume controlled, deburr and re-protect cut edges.
Can SGHC be welded?
Resistance spot and MIG/MAG weldable but zinc vapour causes porosity and toxic fume — increase gap/heat input, use forced extraction, and repair welds with zinc-rich paint or spray zinc.
Can SGHC be formed, bent or molded?
Good bending and roll-forming with generous radii (≥1t for thin gauges); avoid deep draws where the hot-rolled commercial-quality base has limited n/r values, and expect some coating powdering at tight radii.
What surface finishes work on SGHC?
Chromate/Cr-free passivation or phosphate pre-treatment before powder coating or PVDF/polyester paint; do not anodize; degrease oiled coils before painting and touch up all sheared edges.
SGHC 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 |
|---|---|---|
| Cbase steel, JIS G3302 commercial quality | ≤ 0.15 | 0.06 |
| Sitypical of DX51D limits | ≤ 0.5 | 0.03 |
| Mn | ≤ 0.8 | 0.35 |
| P | ≤ 0.05 | 0.02 |
| S | ≤ 0.05 | 0.01 |
| Zn coatingcontinuous hot-dip zinc layer, 60–275 g/m² total both sides (Z06–Z27); coating alloy ≥98.5 % Zn with small Al addition | — | — |
| Febalance of base steel | balance | — |
SGHC-R — frequently asked
What is SGHC-R used for?
SGHC-R is typically used for roofing, ducting, appliance housings and structural panels. In short: galvanized commercial-quality sheet; DX51D equivalent; coating replaces paint.
What is the yield strength of SGHC-R?
SGHC-R has a typical yield strength of 240 MPa (34.8 ksi) and a tensile strength of 310 MPa (45 ksi) — weaker than 96% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is SGHC-R easy to machine?
Reasonably — machinability is rated good (62/100, better than 89% of steel grades). Soft and gummy — shear, punch or laser-cut rather than machine; use sharp tooling and keep zinc dust/fume controlled, deburr and re-protect cut edges.
Can SGHC-R be welded?
Yes — weldability is rated good (60/100). Resistance spot and MIG/MAG weldable but zinc vapour causes porosity and toxic fume — increase gap/heat input, use forced extraction, and repair welds with zinc-rich paint or spray zinc.
What surface finishes work on SGHC-R?
Chromate/Cr-free passivation or phosphate pre-treatment before powder coating or PVDF/polyester paint; do not anodize; degrease oiled coils before painting and touch up all sheared edges.
Can SGHC-R be formed, bent or molded?
Good bending and roll-forming with generous radii (≥1t for thin gauges); avoid deep draws where the hot-rolled commercial-quality base has limited n/r values, and expect some coating powdering at tight radii.
What is the maximum service temperature of SGHC-R?
SGHC-R 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.
Sources
- JIS G 3302 — Hot-dip zinc-coated steel sheet and strip — JSA (2019)
- EN 10346 — Continuously hot-dip coated steel flat products (DX51D) — CEN (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials (zinc coatings) — ASM International (2005)
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.