Y12

Data verified

Y12 is China’s standard sulfur-phosphorus free-cutting steel (GB/T 8731), the domestic equivalent of the 1215 concept. It is produced in large volumes for automatic-lathe parts across Chinese machining shops.

AISI1215 (near)

JISSUM family (near)

GBY12 (GB/T 8731)

CategoryCarbon Steel

Chemical composition

Element	Content (%)
C	0.08–0.16
Si	≤0.15
Mn	0.70–1.00
P	0.08–0.15
S	0.23–0.33

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

Properties

Tensile strength	380–460 MPa (hot rolled, typ.)
Density	7.85 g/cm³

Heat treatment

Used as-rolled or cold drawn; no hardening response.

Equivalent grades

Standard	Designation
aisi	1215 (near)
jis	SUM family (near)
gb	Y12 (GB/T 8731)

Compare side by side: Y12 vs 1215 · Y12 vs 12L14

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

Applications & Processing

Applications: Standard fasteners, turned fittings, small shafts, electronic and appliance hardware.

Processing: Excellent machinability; not weldable; keep out of structural and pressure service.

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Source: GB/T 8731 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.