Carbon & alloy steel · BS 970

EN8 (080M40) — Machining & Properties

Typical properties, what EN8 (080M40) is like on a machine tool, what it gets used for, and the tolerance and finishes we hold on it — from a shop that actually machines it, not a datasheet aggregator. Every figure here drives our own calculators.

7.85 g/cm³
Density (typical)
620 MPa
Tensile strength
HB 180
Hardness
Good
Machinability
11.5 µm/m·°C
Thermal expansion
200 GPa
Elastic modulus
±0.020mm
Achievable tolerance

Machining EN8 (080M40)

Machinability is rated good — a well-behaved material to machine with correctly chosen tooling and parameters. Tool and die steels (H13, D2, M2) are typically rough-machined in the annealed condition, hardened and tempered to working hardness, then finish ground or EDM’d to final dimension. Engaging us early in your design allows the sequence to be optimised for minimum distortion.

Our standard achievable tolerance on EN8 (080M40) is ±0.020mm under normal conditions, with tighter tolerances on critical features agreed at quotation. Standard finishes: Black oxide, zinc plate, powder coat. Full material traceability with MTR and CoC documentation on every order.

Typical applications

Shafts, keys, couplings, general engineering, automotive.

Use EN8 (080M40) in our free tools

Other carbon & alloy steel grades we machine: EN3 (070M20) · EN19 (709M40) · EN24 (817M40) · H13 (Hot Work)all 50 grades.

Reference tool. Values are typical for the grade and condition stated and vary by supplier, temper and batch — they are reference data, not a specification. The Material Test Report supplied with your order is the governing document for the material actually used. Figures are provided in good faith for early design guidance and are not a substitute for the published standard or your own engineering judgement. Always verify against the controlled standard and your drawing before manufacture. If a feature is critical, tell us at quotation stage and we'll confirm it explicitly.
Questions engineers actually ask

EN8 (080M40) — FAQ

What is the density of EN8 (080M40)?

7.85 g/cm³ (typical). That is 7850 kg/m³ — our metal weight calculator uses exactly this figure for EN8 (080M40).

What is the tensile strength of EN8 (080M40)?

Typically 620 MPa. Treat it as a typical value, not a specification — the Material Test Report supplied with your order states the actual certified figures for the batch.

Is EN8 (080M40) easy to machine?

Its machinability is rated good — a well-behaved material to machine with correctly chosen tooling and parameters.

What is EN8 (080M40) used for?

Typical applications: Shafts, keys, couplings, general engineering, automotive.

What tolerance can be held when machining EN8 (080M40)?

Our standard achievable tolerance on EN8 (080M40) is ±0.020mm under normal conditions (ISO 2768-f general tolerancing). Tighter tolerances on critical features can be agreed at quotation for specific geometries.

Can Dalloway machine EN8 (080M40)?

Yes — we machine EN8 (080M40) in-house on 3, 4 and 5-axis milling and CNC turning, from single prototypes to production, with MTR and CoC documentation standard. Typical finishes: Black oxide, zinc plate, powder coat.

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