Hard Hobbing

Hard Hobbing is a finish hobbing process for hardened gears.

There are two kinds of Hard Hobbing processes that use carbide hobs. One is "Finish Hobbing" in which hardened gears are "finished" after the initial tooth cutting. The other is "Hardened Solid Gear Hobbing" where hardened solid gear blanks are finished hobbed.

Kashifuji has developed an Auto Part Orientation Device utilizing a special non-contact sensor that quickly and accurately orientates gear teeth to the hob tool.

Finish Hobbing

Hardened Solid Gear Hobbing

Auto Part Orientation Device

Hobbing Video

Hard Hobbing (Finish Hobbing)

The Hard Hobbing process is replacing conventional gear grinding. Hard Hobbing produces high quality and accurate tooth forms in hardened gears at a low cost. Hard Hobbing is becoming widely used in not only gears with a tight radius which are difficult to finish grind, but also for large module gears. Moreover, Hard Hobbing is being employed in the gear finish production line where previously, the finishing processes were gear grinding and/or honing.

Small Diameter parts with limited clearance for a typical grinding wheel

Reduced interference area between
the part and hob cutter.

Smaller interference area of a hob cutter and the jig fixture.
In some cases, a grinding machine cannot
chuck a part due to larger grinding interference.

Increased part chucking rigidity
due to the lower jig fixture.