What is Hollow Chrome Plated Bar

Hollow Chrome Plated Bar (also known as Hollow Chromed Shaft) is a high-precision tubular component manufactured by applying a hard chrome plating layer to the inner and/or outer surfaces of seamless hollow steel tubes. Unlike solid chrome plated rods, its hollow structure offers lightweight advantages while retaining excellent wear resistance and precision, making it a key component in hydraulic/pneumatic systems, linear motion mechanisms, and high-speed rotating equipment. It is widely used in scenarios requiring both high strength, corrosion resistance, and weight reduction—such as hydraulic cylinder piston rods, automated machinery shafts, and aerospace actuators.

• Core Performance Advantages

  • Dual-Sided Protection & Durability: Chrome plating on inner and outer surfaces provides excellent corrosion resistance (resists moisture, chemicals, and dust) and wear resistance—extending service life by 2-3 times compared to unplated hollow bars. The plating layer’s strong adhesion prevents peeling even under high-frequency reciprocating motion.

  • Lightweight & High Strength: Hollow structure reduces weight by 30-50% vs. solid chrome plated rods, optimizing equipment energy efficiency without compromising mechanical performance (yield strength ≥355MPa for standard materials). Ideal for portable machinery and aerospace applications with weight constraints.

  • Precision & Motion Stability: Ultra-low surface roughness (Ra≤0.1μm for high-end models) and excellent straightness minimize friction with seals, bearings, and guide sleeves, reducing system energy consumption by 10-15% and ensuring smooth motion even at high speeds (up to 5m/s).

  • Corrosion & Temperature Resistance: Adapts to extreme working conditions (-40℃~120℃) with customized materials and plating processes. For harsh environments (e.g., marine, chemical), 316 stainless steel base material + hard chrome plating achieves 720-hour salt spray resistance.

  • Easy Installation & Maintenance: Oxide-free surface and precise dimensional tolerance allow direct assembly with cylinders, flanges, and bearings—eliminating secondary processing. The smooth chrome surface reduces contaminant adhesion, lowering maintenance frequency by 40%.

Manufacturing Excellence & Quality Control

Precision Grinding & Polishing

High-precision centerless grinding creates an ultra-smooth base surface, ensuring optimal chrome adhesion and dimensional accuracy before the plating process begins.

Micro-Crack Chrome Plating

Advanced micro-crack chromium plating process ensures superior adhesion, enhanced corrosion resistance, and uniform coating distribution across the entire surface.

Rigorous Testing Protocol

Comprehensive quality verification including salt spray testing (ASTM B117), hardness measurement, dimensional accuracy checks, and ultrasonic flaw detection.

Typical Applications

Hydraulic & Pneumatic Systems

Cylinder piston rods requiring smooth operation and corrosion resistance

Heavy Equipment Components

Pins, shafts, and structural elements in construction and mining machinery

Specialized Machinery

Agricultural equipment, cranes, dump trucks, and industrial automation systems