What is CS Hollow Bar?

Carbon steel hollow bar is a thick-wall seamless tube used as bar stock for machining. It is a round bar with the centre already removed. The wall thickness is substantial, typically 10mm to 50mm, unlike thin-wall pipe or tubing. This makes it a direct substitute for solid bars in applications requiring a bored hole.

A hollow bar plays an important role in saving time and money. Drilling a 100mm deep hole through a solid bar takes time. The drill bit wears. Chips must be cleared. Coolant is consumed. Starting with a hollow bar eliminates all of these problems. You just face the ends and machine the features. The bore is already there, with consistent quality throughout.

The seamless manufacturing process produces a uniform bore with no weld seam. The material properties are consistent from OD to ID. This matters for parts under stress or rotation. Bushings, rollers and sleeves all benefit from starting with a quality hollow bar.

Grades Available

We stock carbon steel hollow bars in these commonly used grades:

  • SAE 1020: General purpose low carbon grade. Good machinability and weldability. Use for non-critical bushings, spacers and parts not requiring heat treatment. Economical choice for moderate-strength applications.
  • SAE 1045: Medium carbon heat-treatable grade. Can be hardened and tempered to achieve 58-62 HRC surface hardness. Use for gears, shafts, pins and wear parts requiring hardness. Most common grade for machined components.
  • EN8 (080M40): British standard medium carbon steel. Good balance of strength and machinability. Equivalent to 1040. Commonly specified for general engineering applications in India.
  • EN9 (070M55): Higher carbon grade for improved wear resistance. Harder than EN8 after heat treatment. Use for applications requiring better surface hardness and abrasion resistance.

Applications of Carbon Steel Hollow Bars

Carbon steel hollow bars serve applications where machined parts require a through-bore:

Machined Components

Bushings, sleeves, spacers and machined parts are the main applications for hollow bars. Any component that would otherwise require boring a solid bar benefits from starting hollow. Hydraulic cylinder parts, bearing housings, coupling sleeves and guide bushings all use this material. It saves time and the shop saves money on every part.

Rollers

Conveyor rollers and industrial rollers start from hollow bar stock. The tube mounts on a shaft through the bore. EN8 and 1045 grades provide good wear resistance for the roller surface. Heat treatment can harden the OD for heavy-duty applications while the bore remains machinable for shaft fit.