What is Honed Tube?

A honed tube is a precision seamless tube with an internally polished bore. The inside surface gets finished through a honing process that creates an extremely smooth finish. Hydraulic cylinders need this smoothness for proper seal function.

Inside a hydraulic cylinder, a piston moves back and forth under high pressure. Seals ride against the cylinder wall. If that wall is rough, the seals wear out fast and leak. The cylinder loses efficiency. With a honed bore, the seals glide smoothly. They last longer and the system holds pressure better.

Standard seamless tubes cannot achieve this level of finish through normal manufacturing. The honing step increases time and cost, but for cylinder applications, the mirror-like internal surface is needed.

Honing Process

Honing uses abrasive stones mounted on a rotating and reciprocating tool. The tool moves in and out while spinning. This combined motion creates a distinctive cross-hatch pattern on the bore surface. Those tiny grooves in the cross-hatch pattern hold oil. When the piston moves, a thin oil film stays on the wall. This lubricates the seals. Without the cross-hatch, the bore would be too slick and oil would scrape off completely. The seals would run dry and fail.
The honing process does several things at once:

  • Removes material to achieve precise ID tolerance
  • Corrects bore geometry (roundness, straightness, taper)
  • Creates the cross-hatch pattern for oil retention
  • Achieves surface finish of Ra 0.2-0.4 μm

MS Honed Tubes Specifications

Our honed tube specifications meet the requirements for hydraulic and pneumatic cylinder manufacturing:

Diameter 40 to 1000 mm
Length 20 meters
Straightness 0.5 / 1000
Roughness (Ra) 0.2 to 0.4 µ
Tolerance EXT DIN 2391
Tolerance INT ISO H8

Applications

Here is where MS honed tubes get used:

Hydraulic Cylinders

This is the main application. Hydraulic cylinders convert fluid pressure into linear force. The cylinder barrel must hold high pressure while allowing smooth piston movement. Construction equipment like excavators and loaders uses dozens of hydraulic cylinders. Industrial presses, injection moulding machines and material handling equipment all rely on hydraulic power. Each cylinder needs a honed tube as its barrel.

Pneumatic Cylinders

Air cylinders work at lower pressures than hydraulic systems. But they still need smooth bores for the durability of the seal. Assembly lines use pneumatic actuators for pick-and-place operations. Packaging machines, sorting systems and automated equipment depend on pneumatic cylinders. The honed surface ensures consistent, leak-free operation over millions of cycles.