When choose 10S20 over 11SMn30?

When the turned part must be case hardened afterwards. 11SMn30’s higher sulfur and near-zero silicon make carburizing unreliable; 10S20 is the EN grade designed for machine-then-carburize production.

Grades · Carbon Steel · 1.0721 (10S20)

1.0721 (10S20)

Data verified

10S20 (1.0721) is a case-hardening free-cutting steel under EN 10087: moderate sulfur (0.15–0.25%) balances machinability against the ability to carburize small parts that need a wear-resistant case — a combination plain free-cutting grades cannot offer.

DIN1.0721 (10S20)

CategoryCarbon Steel

Chemical composition

Element	Content (%)
C	0.07–0.13
Si	≤0.40
Mn	0.70–1.10
P	≤0.06
S	0.15–0.25

Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.

Properties

Case hardness (carburized)	55–62 HRC (typ.)
Tensile strength	360–480 MPa (delivery-condition dependent)
Density	7.85 g/cm³

Heat treatment

Can be case carburized (880–930 °C, quench, low temper) despite the sulfur content; also widely used as-drawn without heat treatment.

Equivalent grades

Standard	Designation
din	1.0721 (10S20)

Compare side by side: 1.0721 (10S20) vs 1215 · 1.0721 (10S20) vs Y12

Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.

Applications & Processing

Applications: Small carburized turned parts: bushings, bolts, levers, fittings and low-duty gear-type components.

Processing: Machines well before carburizing; case depth control needs care because sulfur affects case uniformity — keep to shallow cases (0.3–0.8 mm).

FAQ

When choose 10S20 over 11SMn30?: When the turned part must be case hardened afterwards. 11SMn30’s higher sulfur and near-zero silicon make carburizing unreliable; 10S20 is the EN grade designed for machine-then-carburize production.

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Source: EN 10087 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.