Steel C15R
EN C15R
C15R is a low-carbon (~0.15 % C) case-hardening steel to EN 10084, supplied with a specified hardenability band (R) and 0.02–0.04 % S to improve chip breaking.
Reference datasheet — C15R 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 +A condition
C15R tempers and conditions
C15R is supplied in 8 conditions, soft to hard. +A is the default FabDigit quotes; the values on this page are for it.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
+ADefault Annealed | Standard stock condition for machining and cold forming before carburizing. | 250 | 420 | 30 | 125 HB | — |
Treated for shearability | For wire and bar that must be cold-sheared or cold-headed without cracking. | 260 | 430 | 30 | 130 HB | 10.5 % IACS |
Hot rolled | Cheapest mill condition for parts that will be normalized or carburized anyway. | 280 | 460 | 26 | 135 HB | 10.5 % IACS |
Normalized | Uniform fine ferrite-pearlite grain before carburizing; best baseline toughness. | 285 | 450 | 28 | 135 HB | — |
Treated to ferrite-pearlite structure with specified hardness range | Choose when a controlled microstructure/hardness band is needed for stable machining results. | 290 | 460 | 27 | 150 HB | 10.5 % IACS |
Treated to specified hardness range | Ordered when the machine shop needs a guaranteed narrow hardness band on incoming bar. | 320 | 500 | 24 | 160 HB | 10.5 % IACS |
Carburized and hardened | Final service condition: hard wear-resistant case (~0.2–0.8 mm) over a tough low-carbon core. | 400 | 650 | 13 | 60 HRC | — |
Cold drawn | Close tolerance bright bar for pins, shafts and screw-machine parts needing higher as-supplied strength. | 450 | 560 | 12 | 165 HB | — |
What is C15R?
C15R is a low-carbon (~0.15 % C) case-hardening steel to EN 10084, supplied with a specified hardenability band (R) and 0.02–0.04 % S to improve chip breaking. It is chosen where a hard carburized wear surface over a tough core is required, and is stocked as hot-rolled and bright-drawn bar and wire in +U, +A, +N, +FP, +S, +TH and +C conditions. Core properties are modest — about 250 MPa yield, 420 MPa tensile, 30 % elongation and 125 HB — so load capacity comes from the case, not the base steel. Bare surfaces rust and welding after carburizing is not allowed; C15E is the alternative where the sulphur addition is unwanted. C15R has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,460°C (2,660 °F). C15R has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 420 MPa (60.9 ksi) — weaker than 94% of steel grades. Elongation at break is 30% and the elastic modulus is 205 GPa (29.7 Msi).
What is C15R used for?
- Carburized gears
- Pins
- Cam followers
- Small shafts
Advantages
- Forms and bends easily — 90/100, better than 98% of steel grades
- Ductile — tolerates forming and impact — 30%, better than 93% of steel grades
- Readily welded — 92/100, better than 93% of steel grades
- High electrical conductivity — 10.5 % IACS, better than 89% of steel grades
- Conducts heat well — 50 W/m·K (28.9 BTU/hr·ft·°F), better than 87% of steel grades
Limitations
- Low strength — 250 MPa (36.3 ksi), worse than 94% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
C15R properties
Typical room-temperature values for C15R-+A; bars are the position among steel grades.
Physical3
C15R has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,460°C (2,660 °F).
Mechanical16
C15R has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 420 MPa (60.9 ksi) — weaker than 94% of steel grades. Elongation at break is 30% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
C15R is rated for continuous service to 400°C (752 °F). It conducts heat at 50 W/m·K (28.9 BTU/hr·ft·°F), better than 87% of steel grades. Thermal expansion is 11.8 µm/m·K (6.56 µin/in·°F).
Electrical3
C15R conducts electricity at 10.5 % IACS, better than 89% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of C15R takes about 25 MJ of energy and emits 2.1 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability6
C15R's machinability is fair (52/100, better than 52% of steel grades); weldability excellent (92/100); formability excellent (90/100).
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. C15R is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C15R
Is C15R easy to machine?
Gummy when soft-annealed — use sharp positive-rake tools, high speed and good chip control; the 0.02–0.04 % S in the R grade gives noticeably better chip breaking and finish than C15E.
Can C15R be welded?
Excellent weldability by all arc, resistance and laser processes with CE ≈ 0.25; no preheat below ~30 mm, but never weld after carburizing.
Can C15R be formed, bent or molded?
Very good cold formability in +A/+S: deep drawing, cold heading, bending to tight radii; hot forge at 1050–1200 °C, normalize afterwards.
C15R 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 |
|---|---|---|
| C | 0.12 – 0.17 | 0.15 |
| Si | ≤ 0.4 | 0.25 |
| Mn | 0.3 – 0.6 | 0.45 |
| P | ≤ 0.04 | 0.02 |
| SR = controlled sulphur range for machinability | 0.02 – 0.04 | 0.03 |
| Crresidual | ≤ 0.4 | 0.1 |
| Niresidual | ≤ 0.4 | 0.1 |
| Moresidual; Cr+Mo+Ni ≤ 0.63 typical | ≤ 0.1 | 0.03 |
| Fe | balance |
What surface finishes work on C15R?
No natural corrosion resistance — zinc plate, phosphate + oil, black oxide or paint; case-hardened surfaces polish and grind well but must be re-passivated/oiled.
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 C15R in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does C15R cost?
C15R 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.
C15R — frequently asked
What is C15R used for?
C15R is typically used for carburized gears, pins, cam followers and small shafts. In short: free-cutting case-hardening steel; machines better than C15E; specified hardenability band.
What is the yield strength of C15R?
C15R has a typical yield strength of 250 MPa (36.3 ksi) and a tensile strength of 420 MPa (60.9 ksi) — weaker than 94% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is C15R easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Gummy when soft-annealed — use sharp positive-rake tools, high speed and good chip control; the 0.02–0.04 % S in the R grade gives noticeably better chip breaking and finish than C15E.
Can C15R be welded?
Yes — weldability is rated excellent (92/100). Excellent weldability by all arc, resistance and laser processes with CE ≈ 0.25; no preheat below ~30 mm, but never weld after carburizing.
What surface finishes work on C15R?
No natural corrosion resistance — zinc plate, phosphate + oil, black oxide or paint; case-hardened surfaces polish and grind well but must be re-passivated/oiled.
Can C15R be formed, bent or molded?
Very good cold formability in +A/+S: deep drawing, cold heading, bending to tight radii; hot forge at 1050–1200 °C, normalize afterwards.
What is the maximum service temperature of C15R?
C15R 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.
What is the difference between C15R +A and C15R-CH?
+A is the default condition — standard stock condition for machining and cold forming before carburizing. CH: final service condition: hard wear-resistant case (~0.2–0.8 mm) over a tough low-carbon core. Yield strength is 250 MPa in +A versus 400 MPa in CH.
How much does C15R cost?
C15R 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 10084 — Case hardening steels: technical delivery conditions — CEN (2008)
- EN 10277 — Bright steel products — CEN (2018)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (carburizing) — ASM International (1991)
- Stahlschlüssel / Key to Steel — 1.1140 C15R — Verlag Stahlschlüssel (2023)
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.