When selecting a 1045 Chrome Plated Bar, translating "performance" into verifiable parameters, the following six items are crucial:
1. Base Material Chemical Composition: Medium-carbon structural steel with 0.42–0.50% carbon and 0.60–0.90% manganese, ensuring a yield strength ≥ 350 MPa and tensile strength of 580–750 MPa after tempering, providing both strength and ease of machining.
2. Surface Chrome Plating Thickness: Hydraulic shafts commonly use 20 μm (0.0008″) or thicker; for heavy-duty or marine environments, 25–30 μm (0.001″) is selected, increasing salt spray life from 48 h to 500 h.
3. Surface Hardness and Roughness:
Chromium plating HV 850-1000 (approximately HRC 63-68), providing a wear-resistant shell; after fine grinding, Ra ≤ 0.25 μm, reducing the frictional temperature rise of seals by 8–12%.
4. Diameter Tolerance and Straightness:
Standard grade h7 (-0/–0.025 mm to Ø51 mm), high-precision grade h6; straightness ≤ 0.3 mm/1000 mm, ensuring no jamming in long-stroke cylinders.
5. Induction Hardening (IHCP) Required: For applications requiring higher impact resistance, select the "tempering + induction hardening + chrome plating" version: surface hardness HRC 50-52, effective hardened layer ≥ 0.05 mm, dent resistance 3 times higher than non-hardened bars.
6. Dimensions and Supply Length: Standard outer diameter 19-127 mm, length 4-6 m; dimensions outside this range require custom rolling. Before placing an order, verify the machine's maximum processing diameter and material length to minimize waste from secondary sawing.
