I. Base Material

Item	Technical Parameters
Base Material Grade	17-4PH Precipitation Hardening Stainless Steel
Chinese National Standard Grade	05Cr17Ni4Cu4Nb
UNS Grade	S17400
DIN Grade	1.4542
Surface Treatment	Chrome Plated
Chrome Plated Coating Thickness	Diameter ≤φ20: 15μm; Diameter＞φ20: 20μm, thickness customizable as required
Surface Hardness of Chrome Plated Layer	HV800～1100
Common Diameter Range	φ3.0mm～φ300mm
Diameter Tolerance	Standard grade: h8, h9; High precision grade: h7, f7, g6, h6
Roundness	≤1/2 of diameter tolerance
Straightness	≤0.10mm/1000mm
Standard Length	Fixed length of 3 meters for φ40mm and below; fixed length of 6 meters for sizes above φ40mm, custom fixed lengths available for large specifications
End Face Requirements	Flat ends with chamfering and deburring

II. Chemical Composition of Base Material (Mass Fraction wt%)

C	Si	Mn	P	S	Cr	Ni	Cu	Nb
≤0.07	≤1.00	≤1.00	≤0.040	≤0.030	15.00～17.50	3.00～5.00	3.00～5.00	0.15～0.45

III. Mechanical Properties

Condition	Tensile Strength ≥MPa	Yield Strength ≥MPa	Elongation ≥	Hardness HRC
A (Solution Annealed)	1255	1105	3%	≤38
H900	1310	1180	10%	40–45
H1025	1060	1000	12%	35–39
H1075	1000	865	13%	33–37
H1150	930	725	16%	28–32

IV. Machining Process & Surface Roughness

Process Type	Complete Process Flow	Surface Roughness
Process 1	Hot-rolled base material → Precision Drawing → Centerless Precision Grinding → Polishing → Chrome Plated → Secondary Polishing	Ra ≤0.2μm
Process 2	Hot-rolled base material → Peeling & Straightening → Centerless Precision Grinding → Polishing → Chrome Plated → Secondary Polishing	Ra ≤0.2μm
Process 3	Forged Round Bar → Turning Finishing → Centerless Precision Grinding → Polishing → Chrome Plated → Secondary Polishing	Ra ≤0.2μm

V. Coating & Physical Properties

Item	Parameter Description
Coating Adhesion	No peeling or flaking, qualified in bending resistance test
Corrosion Resistance	The base material features high strength and inherent corrosion resistance; Chrome Plated provides additional protection, greatly improving wear resistance, rust prevention and anti-aging performance
Coefficient of Friction	Dense and smooth surface for low-friction operation, featuring impact resistance, scratch resistance and high wear resistance
Magnetism of Base Material	Magnetic

VI. Application Scenarios
High-end hydraulic and pneumatic components, high-strength mold shafts, aerospace precision parts, food and medical equipment, marine anti-corrosion structural components, heavy-load wear-resistant piston rods, high-strength transmission shafts for corrosive environments.