STPG370 vs A106 Gr.A?

Counterpart grades for pressure pipe: tensile classes match (≥370 MPa) and chemistry windows overlap closely. Certificates are often cross-accepted for non-certified work; for code-stamped piping the named standard governs.

Grades · Pipe & Tube Steel · STPG370

STPG370

Data verified

STPG370 is the JIS G3454 carbon steel pipe for pressure service at the 370 MPa tensile level — the Japanese counterpart class to ASTM A106 Grade A. It is a fully chemistry-controlled pipe grade (unlike the SS structural grades) for pressure piping up to about 350 °C.

DINP235TR1 type (near)

AISIA106 Gr.A type (near)

JISSTPG370 (JIS G3454)

CategoryPipe & Tube Steel

Chemical composition

Element	Content (%)
C	≤0.25
Si	≤0.35
Mn	0.30–0.90
P	≤0.040
S	≤0.040

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

Properties

Tensile strength	≥370 MPa
Yield strength	≥215 MPa
Density	7.85 g/cm³
Product form	Carbon steel pipe for pressure service (JIS G3454)

Heat treatment

As manufactured (seamless or electric-resistance welded); normalize after hot forming where the piping code requires.

Equivalent grades

Standard	Designation
din	P235TR1 type (near)
aisi	A106 Gr.A type (near)
jis	STPG370 (JIS G3454)
gb	20 (near)

Compare side by side: STPG370 vs STPG410 · STPG370 vs STKM13A

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

Applications & Processing

Applications: Pressure piping, plant and power piping, steam and process lines, general pressure-service tube.

Processing: Good weldability; bevel and weld with standard carbon-steel pipe practice. Hydrostatic or NDT requirements follow the purchaser’s piping code, not the grade itself.

FAQ

STPG370 vs A106 Gr.A?: Counterpart grades for pressure pipe: tensile classes match (≥370 MPa) and chemistry windows overlap closely. Certificates are often cross-accepted for non-certified work; for code-stamped piping the named standard governs.

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Source: JIS G3454 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.