Material Type

Piston rods are usually made of high-strength, wear-resistant and corrosion-resistant steels, such as CK45, 40Cr, 42CrMo4, 20MnV6, SS430, SS304, etc. These materials have good mechanical properties and processing properties, and are suitable for manufacturing high-precision piston rods.

Material Properties

CK45: Medium carbon steel with good mechanical properties and processing properties, with a hardness of 15-20 HRC after normalizing treatment, and a hardness of up to 28-30 HRC after quenching and tempering.

42CrMo4: Alloy steel with higher strength and toughness, suitable for high dynamic use.

20MnV6: After hardening and hard chrome plating, it is suitable for high stability and heavy load use.

Chemical composition

Take CK45 as an example, its chemical composition includes carbon (C) 0.40-0.50%, manganese (Mn) 0.60-0.90%, silicon (Si) 0.035%, sulfur (S) 0.035%, phosphorus (P) 0.035%.

Mechanical properties

Tensile strength: ≥630 MPa.

Yield strength: ≥380 MPa.

Elongation: ≥15%.

Surface treatment and quality control

Surface treatment

Hard chrome plating: The thickness of hard chrome plating is usually 20-50 microns, the hardness is ≥850HV, and the surface roughness Ra ≤0.2 microns.

Induction hardening: The surface hardness is increased by induction hardening, and the hardness can reach 50-55 HRC.

Quality control

Dimensional accuracy: The diameter tolerance meets the ISO f7 standard.

Straightness: Straightness ≤0.2 mm/m.

Roundness: The roundness error does not exceed half of the outer diameter tolerance.

Corrosion resistance

Hard chrome plating and induction hardening treatment significantly improve the corrosion resistance and wear resistance of the piston rod, and can pass the salt spray test to ensure long-term use in harsh environments.