Drill Size Chart for Number and Letter GaugesExplore further
2018-9-9u2002·u2002These specialist drill bits are used for drilling centreholes at two different angles, 60 degrees and90 degrees. They are commonly used to drill lathe centres and spotting drills, i.e.marking holes to guide twist drilling. The drill size chart below contains all commonly used centre drill bit sizes. Size designation Drill diameter [inches (mm)]
Get Price