Description of π YG 1 Spotting Uncoated Straight Diameter Cutting Tools - Enhanced Accuracy and Professional Results
NC spotting drill. 90 Degree point angle. Made of 8 percent cobalt and high speed steel. For more precise centering work on NC/CNC machine. A larger diameter in respect to the subsequent drilling tool permit to obtain the centering and chamfering simultaneously.
90 degrees is a big angle. According to McMaster, the starting angle should be slightly larger than the drilling angle. In any case, this 90 can only be used to a limited extent for me.
This is good for starting small drills in the right place. The 90 degree point makes it fairly easy to start the hole exactly along the marker line. I'm using this with an aluminum drill press, so I'm not sure how well it will work/hold up with harder materials. Update: I ended up replacing it with a Kobalt (Morse) brand drill bit because it was starting to dull. They don't work well, even if they're a bit boring.