Chrome Plated C20 Tube

The Chrome Plated C20 Tube is precision-ground and hard chrome plated from premium C20 (20# / AISI 1020) low-carbon seamless steel tube in a non-heat-treated condition. C20 low-carbon steel features excellent plasticity, toughness and outstanding weldability, making it easy to process. As a hollow piston rod or cylinder barrel tube, it maintains high OD accuracy and surface performance while significantly reducing weight and enabling internal fluid passage. It is widely used in construction machinery, agricultural equipment, automotive components and general industrial medium/low-pressure hydraulic systems requiring excellent weldability with weight or flow optimization—an economical and practical solution for lightweight welded structures and cost efficiency.

• Outer Diameter: Mainly φ25–300 mm, larger custom sizes accepted

• Length: ≤8000 mm, custom lengths available

• Straightness: ≤0.2 mm/M

• Tolerance Grades: IT6–IT9

• OD Tolerance: According to ISO f7/f8/g6/h7/h8/h9; customized tolerances available upon request

• Ovality: Half of the tolerance value ISO f7

• Heat Treatment: None; customization options include Carburizing, Quenched & Tempered and Induction Hardening

• Core Hardness: ≤170 HB (approx. 130–170 HB)

• Surface Treatment: Hard Chrome Plated; customization options: EN Plating / Zinc Plating / Laser Cladding / Carburizing / Thermal Spraying / Ceramic Coating

• Chrome Thickness: ≥10 μm, mainly 20–40 μm; can be over 100 μm for high-standard requirements

• Chrome Layer Hardness: 850–1150 HV (Vickers 100 gf)

• Surface Roughness: Ra≤0.2 μm, Rt≤2 μm

• Weldability: Excellent (C20 low carbon content ensures outstanding weldability, typically without special preheating; post-weld stress relieving is recommended for critical components)

• Packing: Anti-rust oil + cardboard tube/plastic sleeve + wooden case

• Hollow structure effectively reduces weight, lowering equipment load and energy consumption, supporting lightweight design trends

• Can serve as a hydraulic fluid passage, simplifying system design and saving space and piping costs

• C20 low-carbon steel base offers excellent ductility, toughness and superior weldability—ideal for welded structural components

• Strict f7 OD tolerance and low ovality ensure precise sealing and smooth operation

• Hard chrome layer at 850–1150 HV delivers reliable wear and corrosion resistance

• An economical low-carbon steel chrome plated tube combining excellent manufacturability with high value

• Full customization of wall thickness, internal bore, heat treatment and surface finishing to meet diverse OEM requirements

In addition to standard specifications, we offer:

• Custom OD, ID and wall thickness

• Custom lengths

• Tolerance grades and non-standard OD tolerances

• Higher straightness and internal bore precision requirements

• Heat treatment options: Carburizing, Q&T, Induction Hardening

• Surface treatment alternatives: zinc plating, electroless nickel, laser cladding, carburizing, thermal spray, ceramic coating

• Special chrome layer thickness

• Enhanced corrosion resistance and dedicated packing solutions

Limits and Fits Table

The table below provides shaft deviation values for commonly used tolerance grades f7, f8, g6, h7, h8, and h9 to assist your selection according to seal fits.

Chemical Composition

The table presents the standard chemical composition of frequently used materials such as CK45, 25Mn, 20#, ST52, 40Cr, 42CrMo4, 20MnV6 and 38MnVS6 for your reference.

Mechanical Properties

The following table lists reference tensile strength, yield strength, elongation and impact energy values for CK45 (hot-rolled, cold-drawn, Q&T), 25Mn, 20#, ST52, Q345D, 40Cr, 42CrMo4, 20MnV6 and 38MnVS6 under various conditions.