Review on 🔧 Irwin 316015 Cobalt Drill Set by Durioki Cordaro

Drills will not drill through hardened steel. Tried increasing the 3/16" hole to 1/4". A drilling speed of 500 rpm, a medium feed rate and lubricating oil were used. The drill bit immediately wore about 3/8 inch. Irwin and the supplier blamed the user instead of acknowledging the drill's failure. Initially I couldn't use an HSS drill bit and the same setting and it didn't help, but the original drill bit dulled but didn't wear down like an Irwin 8% cobalt bit. Eventually I managed to enlarge the hole with a competitor's cobalt chisel with the same setting. Also, instead of refunding my original purchase price, the seller charged me a 50% restocking fee. Never buy an Irwin tool again or buy from this seller.