OH Hollow Bar

“OH” Hollow Bar is an oil-hardening tool steel tubing designed to reduce time and costs in hollow bar applications.

Benefits of “OH” Hollow Bar

  • Spheroidize Annealing – Assures uniform grain, maximum machinability and eliminates hard spots.
  • Non-Deforming – Easy heat treatment with minimum of dimensional change.
  • Minimizes Machining – Drilling solid bars is not required.
  • Wear Resistance – This deep hardening steel provides excellent wear resistance with subsequent heat treatment.
  • Safe Hardening – Heat treating at recommended temperatures reduces cracks and minimizes deformation.


Heat Treatment

AC1 1340   Ar31320

AC3 1415    Ar1 1270

Normalize: Air cool from 1650-1700ºF

Anneal: Furnace cool from 1425-1400ºF

Spheroidize: Slow cool (about 5ºF/hr.) following austenitizing by extended heating at a temperature near the Acm point, or by isothermal transformation at 1275ºF following austenitizing.

Harden: Quench in water from 1425-1475ºF or quench in warm oil from 1500-1550ºF then temper to desired hardness.

Welding not recommended and should be avoided with thin wall requirements.

“OH” Hollow Bar Applications

The excellent wear and abrasion resistance of “OH” Hollow Bar make it valuable in applications such as:

  • Ball and Roller Bearings
  • Bushings
  • Collets and Accessory Parts
  • Hydraulic Valve Parts
  • Slitting Cutters and Roll Slitters
  • Rolls – feed, guide, forming, end, straightening, leveling, slitting, crushing
  • Mandrels
  • Wear Rings

Stock Size Range

Comes in OD sizes from 1.00″ – 10.497″ and ID sizes from 0.512″ – 7.833″ with larger sizes available on request. Comes in random lengths or cut-to-size pieces. Please indicate finished sizes with RFQs/orders.