Steel En34
En34 is a low-alloy nickel case-hardening steel in the BS 970 family, supplied annealed (A), normalized (N), cold drawn (CD), case hardened (CH) and quenched and tempered (QT).
Reference datasheet — En34 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 N condition
En34 tempers and conditions
En34 is supplied in 5 conditions, soft to hard. N 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 |
|---|---|---|---|---|---|---|
Solution annealed | Choose for maximum softness before heavy machining, cold forming or deep upsetting of blanks that will later be carburized. | 300 | 500 | 28 | 150 HB | — |
NDefault Normalized | Standard stock condition for carburizing blanks: uniform fine grain, good machinability, core properties before case hardening. | 400 | 620 | 21 | 180 HB | — |
Cold drawn | Pick for close-tolerance bright bar for pins, spindles and screw-machine parts where the part is finished before case hardening. | 550 | 690 | 13 | 205 HB | — |
Quenched and tempered | Used when a tough medium-strength part is needed without a case, or to characterise the refined core of carburized components. | 590 | 780 | 16 | 24 HRC | — |
Carburized and hardened | The service condition for gears, pins and cams: 0.5–1.5 mm hard case at ~58–62 HRC over a tough 250–320 HB nickel-steel core. | 600 | 800 | 13 | 60 HRC | — |
What is En34?
En34 is a low-alloy nickel case-hardening steel in the BS 970 family, supplied annealed (A), normalized (N), cold drawn (CD), case hardened (CH) and quenched and tempered (QT). It is used for lightly stressed carburized parts that need a tough core rather than maximum strength: the default condition gives 400 MPa yield, 620 MPa tensile, 21 % elongation and 180 HB (89 HRB), with machinability 60, weldability 62 and formability 58 — the best all-round workability in this group. Core strength is well below En30B or En39, and the steel has no corrosion resistance, so plated or oiled protection is required. Step up to En30B when core loads are high. En34 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). En34 has a yield strength of 400 MPa (58 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of steel grades. Elongation at break is 21% and the elastic modulus is 207 GPa (30 Msi).
What is En34 used for?
- gears
- pins
- small shafts
Limitations
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
En34 properties
Typical room-temperature values for En34-N; bars are the position among steel grades.
Physical3
En34 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical14
En34 has a yield strength of 400 MPa (58 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of steel grades. Elongation at break is 21% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
En34 is rated for continuous service to 300°C (572 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
En34 conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (13/100), better than 66% of steel grades.
Sustainability4
Producing a kilogram of En34 takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability7
En34's machinability is good (60/100, better than 83% of steel grades); weldability good (62/100); formability good (58/100).
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. En34 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with En34
Is En34 easy to machine?
Machine in the normalized or annealed state with carbide at 100–160 m/min; gummy chips respond well to sharp positive tooling and generous coolant — finish all cutting before carburizing, then grind.
Can En34 be welded?
Low carbon equivalent gives good arc weldability with low-hydrogen consumables and 100–150 °C preheat; never weld through a carburized case, and re-carburize or stress-relieve after welding.
Can En34 be formed, bent or molded?
Hot forge 1150–850 °C then normalize at 880–910 °C; annealed bar cold-heads and bends acceptably, cold-drawn bar needs generous bend radii.
En34 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 |
|---|---|---|
| Clow carbon for a tough core prior to carburizing | 0.1 – 0.18 | 0.14 |
| Si | 0.1 – 0.35 | 0.25 |
| Mn | 0.35 – 0.75 | 0.55 |
| Ninickel is the principal alloying addition of the En34 type | 1.25 – 2 | 1.6 |
| Crresidual/optional in some mill practices | ≤ 0.3 | 0.15 |
| Mosmall Mo addition in Ni-Mo variants of this En number | ≤ 0.25 | 0.1 |
| S | ≤ 0.05 | 0.03 |
| P | ≤ 0.05 | 0.03 |
| Fe | balance |
What surface finishes work on En34?
No inherent corrosion resistance — protect with black oxide, phosphate + oil, zinc or nickel plating (bake to avoid hydrogen embrittlement after case hardening); hardened cases grind and polish to a fine bearing finish.
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
How much does En34 cost?
En34 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.
En34 — frequently asked
What is En34 used for?
En34 is typically used for gears, pins and small shafts. In short: most machinable carburizing grade; weldable before case hardening; tough core, light duty.
What is the yield strength of En34?
En34 has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is En34 easy to machine?
Reasonably — machinability is rated good (60/100, better than 83% of steel grades). Machine in the normalized or annealed state with carbide at 100–160 m/min; gummy chips respond well to sharp positive tooling and generous coolant — finish all cutting before carburizing, then grind.
Can En34 be welded?
Yes — weldability is rated good (62/100). Low carbon equivalent gives good arc weldability with low-hydrogen consumables and 100–150 °C preheat; never weld through a carburized case, and re-carburize or stress-relieve after welding.
What surface finishes work on En34?
No inherent corrosion resistance — protect with black oxide, phosphate + oil, zinc or nickel plating (bake to avoid hydrogen embrittlement after case hardening); hardened cases grind and polish to a fine bearing finish.
Can En34 be formed, bent or molded?
Hot forge 1150–850 °C then normalize at 880–910 °C; annealed bar cold-heads and bends acceptably, cold-drawn bar needs generous bend radii.
What is the maximum service temperature of En34?
En34 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.
What is the difference between En34-N and En34-CH?
N is the default condition — standard stock condition for carburizing blanks: uniform fine grain, good machinability, core properties before case hardening. CH: the service condition for gears, pins and cams: 0.5–1.5 mm hard case at ~58–62 HRC over a tough 250–320 HB nickel-steel core. Yield strength is 400 MPa in N versus 600 MPa in CH.
How much does En34 cost?
En34 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
- BS 970: Wrought steels for mechanical and allied engineering purposes (En-series / Part 3 case-hardening steels) — BSI (1991)
- Handbook of Comparative World Steel Standards — ASTM International (2016)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 4 — Heat Treating (carburizing and case hardening) — ASM International (1991)
- 20CrNi/20CrMnTi — Mysteel (2025)
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.