2015
John O’Neil
Dallas, TX
The presentation will cover the following: 1) Microscopic study of the tool marks created by a twist drill bit in the bottom of a drilled hole and on the chips left behind by the drilling process; 2) Twist drill bit sizes defined by the four systems used in the United States; 3) The color of twist drill bits and what they mean; 4) Variations in point angles and measuring it; 5) Standardized nomenclature of the twist drill bit. After this presentation, the examiner will have a better understanding of a twist drill bit and how to exclude, include and/or identify the submitted drill bit.