IRWIN Lettered and Numbered Drill Bits information:
Letter and numbered drill bits were developed to make up the gaps in betwee... read more
How do I resharpen Speedbor flat bits?
Use a small file to sharpen the top of the cutting edge and inside the spur... read more
Are Irwin cobalt drill bits coated like the titanium ones? If the cobalt bits are rockwell hardness 66 - 67 HRc, what hardness are the titanium bits? Once you sharpen a cobalt bit and the gold coating is gone, is it just a regular bit?
Cobalt bits are not coated, they are cobalt steel through and through. At t... read more