Review on SPKLINE Cobalt Jobber Length Stainless Cutting Tools for Industrial Drill Bits by Bob Walters

These bits worked fine initially. Using these coupled with cutting fluid, I drilled through my RV's chassis to install leveling bushings. Pre-drill pilot holes before switching to these bits. The first hole went very smoothly, but the second hole was about halfway through (mind you, I was drilling 1/4" steel) when the drill suddenly broke right above the chuck. The other half of the bit went out of frame. The second bat went through most of the work when part of the bat was shaved off like pencil shavings making it less than 5/16 in. For the price I wasn't expecting flawless performance but these were rubbish beats.