I. Basic Material

Item	Technical Parameter
Material Grade	431
Chinese National Standard Grade	17Cr16Ni2 (1Cr17Ni2)
UNS Grade	S43100
DIN Grade	1.4057

II. Chemical Composition (Mass Fraction wt%)

C	Si	Mn	P	S	Cr	Ni
≤0.20	≤1.00	≤1.00	≤0.040	≤0.030	15.00～17.00	1.50～2.50

III. Mechanical Properties

Item	Mechanical Property
Tensile Strength Rm	≥860 MPa
0.2% Proof Strength Rp0.2	≥655 MPa
Elongation after Fracture A	≥15%
Brinell Hardness	260～300 HB

IV. Dimensional Accuracy Specifications

Item	Technical Requirements
Common Diameter Range	φ3.0mm ～ φ300mm
Diameter Tolerance	Standard: h8, h9; High Precision: h7, f7, g6, h6
Roundness	≤1/2 of diameter tolerance
Straightness	≤0.10mm/1000mm
Standard Length	φ40mm and below: 3 meters; Over φ40mm: 6 meters available (custom fixed lengths supported)
End Face Requirements	Flat ends, chamfered and deburred

V. Processing Technology & Surface Roughness

Process Type	Complete Process Flow	Surface Roughness
Process 1	Hot-rolled base material → Precision drawing → Centerless precision grinding	Ra 0.4～0.8μm
Process 2	Hot-rolled base material → Peeling and straightening → Centerless precision grinding	Ra 0.4～0.8μm
Process 3	Hot-rolled base material → Peeling and straightening → Centerless precision grinding → Polishing	Ra ≤0.2μm
Process 4	Hot-rolled base material → Quenching and tempering → Peeling and straightening → Centerless precision grinding → Polishing	Ra ≤0.2μm
Process 5	Hot-rolled base material → Peeling and straightening → Surface quenching → Centerless precision grinding → Polishing	Ra ≤0.2μm

VI. Physical Properties and Surface Quality

Item	Parameter Description
Material Density	7.71 g/cm³
Magnetism	Magnetic
Surface Appearance Quality	Free of cracks, peeling, pinholes, scale, rust and impact bruises

VII. Application Scenarios
Pump shafts, valve stems, piston rods, aerospace components, marine equipment, high-strength corrosion-resistant precision shafts, wear-resistant precision structural parts.