... .Grade:G500/G1000 ISO qulified company Production name1/4 inch steel ball for bicycle spare partssize1/4",3/16",5/32 ... balls are case-hardened only(surface heat treatment),low carbon steel balls offer considerable saving in all those applications which do ... use of through hardened balls2,the most common applications include furniture wheels,bearings for darwers,locks,grease,nipples,sliding,blocks,toys ...