The fillets at the root of the gear are usually the areas of high stress and should be shot-peened. However, it has also been found that the fine indentations produced by shot-peening on the face of the gear teeth act as tiny oil reservoirs which help to give better lubrication, reduce fretting and scoring, and reduce operating temperature. Gears which have to be held to very close tolerances may be lapped after shot-peening or the gear face can be masked if desired.

Gears are frequently shot-peened after carburizing, as shown in the chart below. One of our customers found that the life of a case-hardened drive gear stressed to 80,000 psi was increased from 200,000 cycles of fatigue life before shot-peening to 30,000,000 cycles after shot-peening. We recommend the used of special hardness (55-65 RC) shot for peening case-hardened carburized gears in order to give a higher magnitude of compressive stress.

New technology in Peening by Engineered Abrasives has been tried, tested and proven on parts which after going through the Peening process has eliminated gear teeth pitting. This is a patented pending process.

• Gears, Shafts, Housings, Etc.
• Peening Medias that are used are Ceramic, Glassbead or Steel Shot

Types of Gears and Shafts for Peening and Deburring to improve Fatigue Life

Engineered Abrasives' machines are designed and set-up to peen critical areas of the part to meet our customers demands.