The smallest details can yield the biggest results. JEGS Valve Spring Shims are not the ordinary piece of heat treated steel most others call a valve spring shim. Our 0.030" and 0.060" thick valve spring shims are case hardened. Our 0.015" shims are made from blue tempered spring steel. These valve spring shims can easily withstand the abuse of a high-performance engine or a daily driver. Each kit includes 16pcs each of 0.015", 0.030", and 0.060" valve spring shims. .