Hard wire has been cold drawn to the required diameter and not subjected to any subsequent treatment process. The steel is usually used without heat treatment or with only tempering to relieve stresses.
Piano wire, on the other hand, is produced in the form of rods. It has a higher than usual content of sulfur and phosphorus intended. For these purposes, such steel is sometimes alloyed with lead and tellurium. However, due to its high concentration of sulfur and phosphorus, it has lower ductility and toughness than those or regular carbon steel and as well as poor weldability.
|Applications||Spring, spoke, shock absorber, shot peening, umbrella rib, concrete steel nail, shutter spring, bed spring, pin, etc.|
|Diameter Range||0.4 - 8.0 mm|
|Raw Material Grades||JIS G3502, JIS G3506, SAE 1040-1080, SWRH 42A/B-SWRH 82A/B, SWRS 62A-82B|