Gears and wheel sprockets are low profile components, but that understated physical form belies an innate knack for handling near unendurable loads. Geometrically detailed, these essential mechanical parts are machined from the finest materials. Manufactured, machined, and balanced, the parts are then heat treated so that they can tolerate high loading factors. Flame hardening is the preferred metal-toughening service on this occasion, but what are the advantages of this technique?

Directional Flame Hardening 

Tight engineering tolerances manufacture dimensionally accurate single-piece gears and wheel sprockets. Teeth mesh, power is transferred, and torque is governed. A quick application of engineering principles is enough to determine these meshing teeth as the site of all mechanical loading, so this outlying area is where the heat treatment process is required. Subsequently, the hardening flame directs case hardening energy straight to the teeth, the site of known wear. Additionally, dimensional tolerances are maintained here, for the flame hardening process does not distort the geometry of the balanced gear.

Highlighting the Effects of Wear 

The guilty culprit in most wear and tear studies is the point where physical contact is made. Gears mostly brush off contact caused wear by using fine lubricants, but these oily substances are mostly there to mitigate frictional influences. Consequently, flame hardening is used to comprehensively reinforce the triangular pitched rim, thus creating a case hardened ring of beveled and pitched gear contacts. Hardened in this manner, the triangular outer rim is now fully capable of enduring the abrasions and impacts that take place when gears dynamically interact.
Targeted Tempering and Highlighted Hardening


There’s a vast range of gear types available on the engineering market. Some products work in tandem with each other, so a quantifiable stress factor is a burden, but it’s manageable. But then there are worm gears and rack and pinion parts, plus a whole range of helical gears. The latter product stretches the meshing interface and adds an angular component to the mix. In order to make these different outer tooth configurations wear-resistant, flame hardening techniques change the fundamental structure of the triangular edges, from each peak to each trough, so that the wear resistance of each heat treated gear wheel is supplemented.

The meshing outer edges of these gears and wheel sprockets represent the harshest focal point in any mechanical power transmission system, so they require protection in the form of a flame hardening heat treatment procedure. Meanwhile, the rest of the wheel, its main body, remains ductile and workable.