29pcs Cobalt Drill Bit Set, M35 High Speed Steel Twist Jobber Length Kit with Metal Index Storage Case, Drill Bits for Metal, Stainless Steel, Cast Iron, Plastic and Wood

I bought a brand new box set of dewalt titanium-nitride coated drills and they werent enough to drill deep holes into the posts without spinning in place. The bits dulled very quickly. I then bought a set of cobalt twist drills for 10 bucks on amazon (ZHUREKER brand) and they cut into the metal just as well as a normal drill bit cuts into wood. dewalt bits- https://share.google/FgL8CLx26pXfwtxdT zhureker cobalt bits (i bought the 10 dollar set) - https://www.amazon.com/ZHUREKER-Cobalt-Drill-Bit-Set/dp/B0FGCP8QMJ I'm very experienced with drilling into many kinds of wood, and while i have next to no experience drilling into metal i know enough to tell when a bit is spinning in place more than it's cutting... I'm surprised to hear you say your bits are effective at making holes in hot wheels metal.