Alloy and special steel bright bars
Alongside our free cutting, mild steel, EN8D and EN8M bright bars, we supply a full range of alloy steels. Chromium, molybdenum, nickel and vanadium additions give these grades higher hardenability, strength, toughness and wear resistance than plain carbon steels. Cold drawing adds close tolerance and a bright, machining-ready surface.
Through-hardening alloy grades
| Grade | Equivalent | Key alloying (typical %) | Typical use |
|---|---|---|---|
| EN19 | 42CrMo4 · AISI 4140 · 709M40 | C 0.35–0.45, Cr 0.9–1.5, Mo 0.2–0.4 | High-tensile shafts, spindles, bolts, gears |
| 4135 | 34CrMo4 · AISI 4135 | C 0.33–0.38, Cr 0.8–1.1, Mo 0.15–0.25 | Medium-section high-strength parts |
| EN24 | 40NiCr2Mo2 · AISI 4340 · 817M40 | C 0.36–0.44, Ni 1.3–1.7, Cr 1.0–1.4, Mo 0.2–0.35 | Heavy-duty shafts, crankshafts, aero & auto parts |
| EN18 | 40Cr4 · AISI 5140 · 530M40 | C 0.35–0.45, Cr 0.85–1.15 | Shafts, gears, steering parts |
| EN16 | 35Mn6Mo3 · 605M36 | C 0.30–0.40, Mn 1.3–1.8, Mo 0.2–0.35 | Gears, connecting rods, high-tensile studs |
| EN31 | 100Cr6 · AISI 52100 · 535A99 | C 0.90–1.20, Cr 1.0–1.6 | Bearings, rollers, gauges, punches, dies |
| EN47 | 50CrV4 · AISI 6150 · 735A51 | C 0.45–0.55, Cr 0.8–1.2, V ≥ 0.15 | Springs, torsion bars, high-fatigue parts |
| EN9 | C55 · AISI 1055 · 070M55 | C 0.50–0.60, Mn 0.5–0.8 | Wear parts, sprockets, cams, blades |
Case-hardening grades
| Grade | Equivalent | Key alloying (typical %) | Typical use |
|---|---|---|---|
| 16MnCr5 | EN 10084 · ≈ AISI 5115 | C 0.14–0.19, Mn 1.0–1.3, Cr 0.8–1.1 | Gears, pinions, cam followers, shafts |
| 8620 | 20NiCrMo2 · SAE 8620 | C 0.18–0.23, Ni 0.4–0.7, Cr 0.4–0.6, Mo 0.15–0.25 | Gears, ring gears, kingpins, shafts |
| EN353 | 15NiCr1Mo12 · 815M17 | C ≈ 0.20, Ni 1.0–1.5, Cr 0.75–1.25, Mo 0.08–0.15 | Heavy-duty transmission gears |
| EN354 | 20NiCrMo13 · 820M17 | C ≈ 0.20, Ni 1.5–2.0, Cr 0.75–1.25, Mo 0.10–0.20 | Heavy-duty gears, pinions, shafts |
Typical ranges for reference — exact limits vary by standard and mill. Each supply is backed by the mill test certificate; please confirm chemistry against your drawing.
Choosing an alloy grade
- High-tensile shafts and bolts: EN19 / 4140, or EN24 for heavier sections and higher toughness.
- Bearings, rollers and wear parts: EN31.
- Springs and fatigue-loaded parts: EN47.
- Gears and pinions needing a hard surface: 16MnCr5, 8620, EN353 or EN354 (carburised).
Frequently asked questions
Is EN19 the same as 4140 and 42CrMo4?
Close equivalents — Cr-Mo steels with about 0.40% carbon, used for high-tensile shafts, spindles and bolts, usually hardened & tempered.
Through-hardening vs case-hardening — what's the difference?
EN19, EN24 and EN31 harden through the section. 16MnCr5, 8620, EN353 and EN354 are low-carbon and are carburised for a hard surface over a tough core — ideal for gears.
Can you supply hardened & tempered bars?
Yes — alloy grades such as EN19 / 4140 can be supplied annealed or Q&T on request. Tell us the hardness or tensile range you need.