Steel SECC · supply condition · default condition
Steel SECC-HR
Properties of the HR condition, compared with the other SECC tempers.
Choose hot-rolled stock when thickness and cost matter more than surface quality; tolerances and finish are coarser, with cold rolling or coating applied in later processing steps.
What is SECC-HR?
SECC-HR is SECC supplied in the HR condition — choose hot-rolled stock when thickness and cost matter more than surface quality; tolerances and finish are coarser, with cold rolling or coating applied in later processing steps. SECC-HR has a yield strength of 220 MPa (31.9 ksi) and a tensile strength of 305 MPa (44.2 ksi) — weaker than 98% of steel grades. Elongation at break is 38% and the elastic modulus is 205 GPa (29.7 Msi). SECC-HR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,500°C (2,732 °F).
Advantages
- Ductile — tolerates forming and impact — 38%, better than 98% of steel grades
- 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
- Forms and bends easily — 85/100, better than 96% of steel grades
- Good corrosion resistance — 30/100, better than 95% of steel grades
Limitations
- Hard to polish — 35/100, worse than 99% of steel grades
- Low strength — 220 MPa (31.9 ksi), worse than 98% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- High embodied carbon — 2.5 kg CO₂/kg, worse than 82% of steel grades
SECC-HR properties
Typical room-temperature values for SECC-HR. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
SECC-HR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,500°C (2,732 °F).
Mechanical12
SECC-HR has a yield strength of 220 MPa (31.9 ksi) and a tensile strength of 305 MPa (44.2 ksi) — weaker than 98% of steel grades. Elongation at break is 38% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
SECC-HR 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
SECC-HR conducts electricity at 11 % IACS, better than 98% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (30/100), better than 95% of steel grades.
Sustainability4
Producing a kilogram of SECC-HR takes about 35 MJ of energy and emits 2.5 kg of CO₂ — more than 86% of steel grades. Typical recycled content is 25%.
Manufacturability7
SECC-HR's machinability is good (65/100, better than 93% of steel grades); weldability very good (80/100); formability excellent (85/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other SECC tempers and conditions
SECC is also supplied in 11 other conditions. The full side-by-side table is on the SECC overview.
- HRDefaultChoose hot-rolled stock when thickness and cost matter more than surface quality; tolerances and finish are coarser, with cold rolling or coating applied in later processing steps.summary only
- GalvanizedDefault stocked SECC coil/sheet: SPCC base, electroplated zinc both sides, chromate passivated, standard temper — general enclosure and bracket work.220 MPa yield · 45 HRB
Working with SECC-HR
Is SECC easy to machine?
Soft and gummy — punch, laser or shear rather than mill; use sharp tools, high rake and light feeds to avoid burrs and zinc smearing, and expect coating loss on all cut edges.
Can SECC be welded?
Excellent resistance spot/projection welding (use ~10–20 % higher current and more frequent tip dressing than bare CR); MIG/TIG needs fume extraction and post-weld zinc-rich touch-up because zinc burns off in the heat-affected zone.
Can SECC be formed, bent or molded?
Very good cold formability in A/S tempers — bends to 1T–2T, deep drawing possible in the soft temper; the zinc layer acts as a mild lubricant but heavy draws can flake it, so galling and die pick-up should be checked.
What surface finishes work on SECC?
Take as-supplied chromate or anti-fingerprint finish for indoor use; phosphate grade or a light alkaline clean plus conversion coat for powder coating; touch up cut edges, welds and drilled holes with zinc-rich primer for humid service.
SECC 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 |
|---|---|---|
| CSPCC base per JIS G3141 | ≤ 0.15 | 0.06 |
| Mn | ≤ 0.6 | 0.3 |
| P | ≤ 0.1 | 0.02 |
| S | ≤ 0.04 | 0.02 |
| Zn coatingElectroplated zinc, ≥99 % Zn; typical coating mass 20/20 g/m² per side (≈2.8 µm), range 8–40 g/m² per JIS G3313 designations E8–E40 | — | — |
| Febase steel | balance | — |
SECC-HR — frequently asked
What is SECC-HR used for?
SECC-HR is typically used for industrial enclosures, computer and server chassis, electrical cabinets and panels, appliance side and back panels, mounting brackets and trays and rack-mount hardware. In short: electro-galvanized commercial coil.
What is the yield strength of SECC-HR?
SECC-HR has a typical yield strength of 220 MPa (31.9 ksi) and a tensile strength of 305 MPa (44.2 ksi) — weaker than 98% of steel grades. Strength varies by condition: see the 12 listed tempers.
Is SECC-HR easy to machine?
Reasonably — machinability is rated good (65/100, better than 93% of steel grades). Soft and gummy — punch, laser or shear rather than mill; use sharp tools, high rake and light feeds to avoid burrs and zinc smearing, and expect coating loss on all cut edges.
Can SECC-HR be welded?
Yes — weldability is rated very good (80/100). Excellent resistance spot/projection welding (use ~10–20 % higher current and more frequent tip dressing than bare CR); MIG/TIG needs fume extraction and post-weld zinc-rich touch-up because zinc burns off in the heat-affected zone.
What surface finishes work on SECC-HR?
Take as-supplied chromate or anti-fingerprint finish for indoor use; phosphate grade or a light alkaline clean plus conversion coat for powder coating; touch up cut edges, welds and drilled holes with zinc-rich primer for humid service.
Can SECC-HR be formed, bent or molded?
Very good cold formability in A/S tempers — bends to 1T–2T, deep drawing possible in the soft temper; the zinc layer acts as a mild lubricant but heavy draws can flake it, so galling and die pick-up should be checked.
What is the maximum service temperature of SECC-HR?
SECC-HR 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 SECC-HR and SECC-1?
HR is the default condition — choose hot-rolled stock when thickness and cost matter more than surface quality; tolerances and finish are coarser, with cold rolling or coating applied in later processing steps. SECC-1: full-hard as-rolled temper — highest strength and flatness, essentially only for flat blanks, shearing and very light forming. Yield strength is 220 MPa in HR versus 540 MPa in SECC-1.
Can FabDigit make parts in SECC-HR?
Yes — SECC-HR is available for sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- JIS G 3313 — Electrolytic zinc-coated steel sheet and strip — JSA (2021)
- JIS G 3141 — Cold-reduced carbon steel sheet and strip (SPCC base) — JSA (2021)
- GB/T 15675 / GB/T 5213 equivalents for — SAC (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials (zinc coatings) — ASM International (2005)
- Electro-galvanized coil (SECC/SECC-N/SECC-AF) product data — Nippon Steel / POSCO / 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.