Steel C8C +U+C
Supply condition · default condition
EN 1.0213
+U+C = cold drawn from untreated (as-rolled) condition
Standard stocked cold-drawn wire/bar: bright surface, close diameter tolerance and work-hardened strength for moderate-upset fasteners.
Values for the +U+C condition
Other C8C tempers and conditions
C8C is listed in 4 conditions; see the grade overview at C8C.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Pick when maximum cold-heading upset ratio and lowest die load are needed before drawing or forming. | 190 | 320 | 36 | 95 HB | — |
Hot rolled | Base hot-rolled wire rod as delivered from the rolling mill, for customers doing their own drawing or annealing. | 215 | 340 | 32 | 100 HB | — |
Spheroidize annealed then cold drawn | Best choice for severe multi-station cold heading/extrusion: annealed ductility retained with drawn size accuracy and lower strength than +U+C. | 335 | 410 | 14 | 120 HB | — |
+U+CDefaultThis page Cold drawn from untreated (as-rolled) condition | Standard stocked cold-drawn wire/bar: bright surface, close diameter tolerance and work-hardened strength for moderate-upset fasteners. | 385 | 460 | 11 | 135 HB | — |
What is C8C +U+C?
C8C +U+C is C8C supplied in the +U+C condition — standard stocked cold-drawn wire/bar: bright surface, close diameter tolerance and work-hardened strength for moderate-upset fasteners. C8C +U+C has a yield strength of 385 MPa (55.8 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 65% of steel grades. Elongation at break is 11% and the elastic modulus is 205 GPa (29.7 Msi). C8C +U+C 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
- High electrical conductivity — 11 % IACS, better than 98% of steel grades
- Readily welded — 95/100, better than 97% of steel grades
- Forms and bends easily — 82/100, better than 94% of steel grades
- Conducts heat well — 51 W/m·K (29.5 BTU/hr·ft·°F), better than 92% of steel grades
Limitations
- Limited ductility — 11%, worse than 89% of steel grades
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
C8C +U+C properties
Typical room-temperature values for C8C +U+C; 15 are specific to this condition. Other listed values are C8C reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
C8C +U+C 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).
Mechanical15
C8C +U+C has a yield strength of 385 MPa (55.8 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 65% of steel grades. Elongation at break is 11% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
C8C +U+C is rated for continuous service to 300°C (572 °F). It conducts heat at 51 W/m·K (29.5 BTU/hr·ft·°F), better than 92% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
C8C +U+C conducts electricity at 11 % IACS, better than 98% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of C8C +U+C takes about 27 MJ of energy and emits 2.1 kg of CO₂ — less than 59% of steel grades. Typical recycled content is 30%.
Manufacturability8
C8C +U+C's machinability is fair (45/100, worse than 65% of steel grades); weldability excellent (95/100); formability very good (82/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C8C +U+C
Is C8C easy to machine?
Soft and gummy — use sharp positive-rake tools, high speed and flood coolant to avoid built-up edge and stringy chips; expect poor chip breaking versus resulfurized grades.
Can C8C be welded?
Excellent by resistance, MIG/MAG, TIG and projection welding; carbon equivalent ~0.15 so no preheat or PWHT is required.
Can C8C be formed, bent or molded?
Designed for multi-station cold heading and cold extrusion; use phosphate + soap or polymer lubricant and specify +AC before high upset ratios to prevent head cracking.
What surface finishes work on C8C?
No corrosion resistance of its own — electro-zinc, hot-dip galvanizing, zinc-flake or phosphate+oil is standard; carburizing/carbonitriding can be added for surface hardness.
C8C 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 |
|---|---|---|
| Ccast/ladle analysis per EN 10263-2 | 0.06 – 0.1 | 0.08 |
| Silow-Si variants specified for galvanizing/wire drawing | ≤ 0.3 | 0.1 |
| Mn | 0.3 – 0.6 | 0.45 |
| P | ≤ 0.03 | 0.02 |
| S | ≤ 0.03 | 0.02 |
| Curesidual limit, restricted for cold-heading quality | ≤ 0.25 | 0.1 |
| Fe | balance | — |
C8C +U+C — frequently asked
What is C8C +U+C used for?
C8C +U+C is typically used for cold-headed fasteners, wire products, cold-formed pins and rivets and small precision cold-forged parts. In short: dedicated cold-heading grade; weldability score 95; poor free-machining behaviour.
What is the yield strength of C8C +U+C?
C8C +U+C has a typical yield strength of 385 MPa (55.8 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 65% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is C8C +U+C easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Soft and gummy — use sharp positive-rake tools, high speed and flood coolant to avoid built-up edge and stringy chips; expect poor chip breaking versus resulfurized grades.
Can C8C +U+C be welded?
Yes — weldability is rated excellent (95/100). Excellent by resistance, MIG/MAG, TIG and projection welding; carbon equivalent ~0.15 so no preheat or PWHT is required.
What surface finishes work on C8C +U+C?
No corrosion resistance of its own — electro-zinc, hot-dip galvanizing, zinc-flake or phosphate+oil is standard; carburizing/carbonitriding can be added for surface hardness.
Can C8C +U+C be formed, bent or molded?
Designed for multi-station cold heading and cold extrusion; use phosphate + soap or polymer lubricant and specify +AC before high upset ratios to prevent head cracking.
What is the maximum service temperature of C8C +U+C?
C8C +U+C is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10263-2 Steel rod, bars and wire for cold heading and cold extrusion — steels not intended for heat treatment — CEN (2017)
- EN 10027-2 Designation systems for steels — numerical system (1.0213) — CEN (2015)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels and High-Performance Alloys — ASM International (1990)
- Machinery's Handbook (machinability ratings, low-carbon steels) — Industrial Press (2020)
- GB/T 6478 (ML08 comparable grade) — SAC (2015)
- Mysteel / SMM · (2026)
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.