Review on DelitonGude Cobalt Metric Suitable Steels by Chris Endricko

These are quality drill bits that are good for drilling in harder steels including stainless steel but are also good for general applications, especially at this price point. The quality of the grinding is no worse than what I've seen. I would describe the finish of the grooves and the cutting edge as "polished", hence the durability. They have the standard 118° point angle that is common on these smaller sizes. With a diameter of approx. 3.0 mm and more, they have an (also excellent) sharpening angle of 135°. HSS-E, also known as M35 or HSS-Co 5% is excellent for harder materials as it can handle the heat generated during cutting without going soft. It's overkill for softer materials like wood, plastic or aluminum but that doesn't stop it from working very well and this price is about what you would expect for 10 pieces of regular high speed steel (HSS M2). before shipment. . With careful use, each of them will last a long time. This 10 pack is probably a lifetime supply for me. Note that these are METRIC bits, they measure exactly 2.50mm (0.0984") which is about 5k larger than 3/32" (0.0938") but still close enough for many purposes. I find it handy to have a set of metric bits because sometimes you need a metric hole and other times they're right in between another size that's better for the job.