Metal Improvement Company provide specialised metal finishing services including heat treatment, surface finishing and in particular, shot peening. Shot peening is a process used to produce a compressive residual stress layer and modify mechanical properties of metals. It entails impacting a surface with shot (round metallic, glass or ceramic particles) with force sufficient to create plastic deformation. It is similar to sandblasting, except that it operates by the mechanism of plasticity rather than abrasion: each particle functions as a ball-peen hammer. In practice, this means that the process removes less material, and less dust created. It was common practice for blacksmiths to hammer peen the concave side of leaf springs; this process enhanced the life of the springs, although the exact mechanism was unknown.

Peening a surface spreads it plastically, causing changes in the mechanical properties of the surface. Shot peening is often called for in aircraft repairs to relieve tensile stresses built up in the grinding process and replace them with beneficial compressive stresses. Metal Improvement Company (MIC), established in 1945, is an internationally recognized industry leader in the aerospace, automotive, power generation, oil and gas, chemical processing, medical and general engineering industries, providing advanced technologies to enhance the performance of metals and materials.