Steel C4C
EN 1.0303
C4C (1.0303) is an extra-low-carbon (about 0.04 % C) cold-heading quality wire-rod steel supplied in +U, +A, +AC, +C and +AC+C conditions.
Reference datasheet — C4C is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the +U condition
C4C tempers and conditions
C4C is supplied in 5 conditions, soft to hard. +U is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Spheroidized rod for the most severe cold-heading/extrusion ratios and for parts to be redrawn afterwards. | 175 | 300 | 43 | 85 HB | — |
Annealed | Pick when maximum softness/ductility is wanted before very heavy upsetting or deep cold extrusion of low-carbon parts. | 180 | 300 | 42 | 88 HB | — |
+UDefault Hot rolled | Standard mill supply condition for wire rod; already soft enough for light-to-moderate heading, or for further drawing. | 210 | 330 | 38 | 95 HB | — |
Spheroidize annealed then cold drawn | The classic fastener-wire condition: annealed for maximum heading ductility, then lightly drawn to size and surface finish. | 355 | 420 | 16 | 120 HB | — |
Cold drawn | Drawn wire/bar with tight size tolerance and higher strength from work hardening; use when the part needs only modest further deformation. | 400 | 460 | 12 | 132 HB | — |
What is C4C?
C4C (1.0303) is an extra-low-carbon (about 0.04 % C) cold-heading quality wire-rod steel supplied in +U, +A, +AC, +C and +AC+C conditions. Its value is ductility rather than strength — roughly 210 MPa yield, 330 MPa tensile, 38 % elongation and 95 HB — so heads and shanks survive severe multi-station upsetting without cracking. Weldability is excellent, but strength is low, machinability is poor (score 42) and there is no corrosion resistance, so parts are plated, galvanized or case-hardened. C2C is the choice when even greater cold-forming reserve is needed. C4C has a density of 7.87 g/cm³ (0.284 lb/in³), heavier than 92% of steel grades. It melts at 1,500°C (2,732 °F). C4C has a yield strength of 210 MPa (30.5 ksi) and a tensile strength of 330 MPa (47.9 ksi) — weaker than 98% of steel grades. Elongation at break is 38% and the elastic modulus is 207 GPa (30 Msi).
What is C4C used for?
- cold-headed bolts and screws
- rivets
- wire fasteners
- cold-formed pins
Advantages
- Forms and bends easily — 96/100, better than 100% of steel grades
- Conducts heat well — 58 W/m·K (33.5 BTU/hr·ft·°F), better than 99% of steel grades
- High electrical conductivity — 11.5 % IACS, better than 99% of steel grades
- Ductile — tolerates forming and impact — 38%, better than 98% of steel grades
- Readily welded — 95/100, better than 97% of steel grades
Limitations
- Low strength — 210 MPa (30.5 ksi), worse than 98% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
C4C properties
Typical room-temperature values for C4C-+U; bars are the position among steel grades.
Physical3
C4C has a density of 7.87 g/cm³ (0.284 lb/in³), heavier than 92% of steel grades. It melts at 1,500°C (2,732 °F).
Mechanical16
C4C has a yield strength of 210 MPa (30.5 ksi) and a tensile strength of 330 MPa (47.9 ksi) — weaker than 98% of steel grades. Elongation at break is 38% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
C4C is rated for continuous service to 400°C (752 °F). It conducts heat at 58 W/m·K (33.5 BTU/hr·ft·°F), better than 99% of steel grades. Thermal expansion is 11.9 µm/m·K (6.61 µin/in·°F).
Electrical3
C4C conducts electricity at 11.5 % IACS, better than 99% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of C4C takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
C4C's machinability is fair (42/100, worse than 73% of steel grades); weldability excellent (95/100); formability excellent (96/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. C4C is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C4C
Is C4C easy to machine?
Soft and gummy — use sharp positive-rake tools, high speed, generous coolant and chip-breaking geometry; expect stringy chips and poor surface unless cold-drawn.
Can C4C be welded?
Excellent weldability by any process (RSW, MIG, TIG, projection); carbon equivalent well under 0.20 so no preheat or PWHT needed.
Can C4C be formed, bent or molded?
Outstanding cold heading/extrusion ductility — tolerates multi-station upsetting and severe reductions; phosphate + soap or polymer lubricant recommended for drawing.
C4C 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 |
|---|---|---|
| Cextra-low carbon, EN 10263-2 | ≤ 0.06 | 0.04 |
| Sialuminium-killed practice; Si often kept low | ≤ 0.3 | 0.1 |
| Mn | 0.2 – 0.45 | 0.3 |
| P | ≤ 0.03 | 0.01 |
| S | ≤ 0.03 | 0.01 |
| Curesidual | ≤ 0.25 | 0.1 |
| Altotal Al, killed/grain-refined | ≥ 0.02 | 0.04 |
| Fe | balance |
What surface finishes work on C4C?
No anodizing; protect by zinc or zinc-nickel electroplating, hot-dip galvanizing, mechanical zinc or Dacromet/zinc-flake; can be carburized or nitrocarburized for surface hardness.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel C4C in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.0303
How much does C4C cost?
C4C is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
C4C — frequently asked
What is C4C used for?
C4C is typically used for cold-headed bolts and screws, rivets, wire fasteners and cold-formed pins. In short: cold-heading quality rod; very high forming ductility; low strength as-formed.
What is the yield strength of C4C?
C4C has a typical yield strength of 210 MPa (30.5 ksi) and a tensile strength of 330 MPa (47.9 ksi) — weaker than 98% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is C4C easy to machine?
Not especially — machinability is rated fair (42/100, worse than 73% of steel grades). Soft and gummy — use sharp positive-rake tools, high speed, generous coolant and chip-breaking geometry; expect stringy chips and poor surface unless cold-drawn.
Can C4C be welded?
Yes — weldability is rated excellent (95/100). Excellent weldability by any process (RSW, MIG, TIG, projection); carbon equivalent well under 0.20 so no preheat or PWHT needed.
What surface finishes work on C4C?
No anodizing; protect by zinc or zinc-nickel electroplating, hot-dip galvanizing, mechanical zinc or Dacromet/zinc-flake; can be carburized or nitrocarburized for surface hardness.
Can C4C be formed, bent or molded?
Outstanding cold heading/extrusion ductility — tolerates multi-station upsetting and severe reductions; phosphate + soap or polymer lubricant recommended for drawing.
What is the maximum service temperature of C4C?
C4C is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does C4C cost?
C4C is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- EN 10263-2 — Steel rod, bars and wire for cold heading and cold extrusion, Part 2: non-heat-treatable steels — CEN (2017)
- EN 10027-2 — Numerical designation system for steels (1.0303) — CEN (2015)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels and High-Performance Alloys — ASM International (1990)
- Machinery's Handbook (machinability ratings, carbon steels) — Industrial Press (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.