Bordo #28 Gauge Bright HSS Jobber Drill 2013-28

28 Gauge Bright HSS Twist
Bordo Wire Gauge Quick Silver M2-HSS Twist Drills.
118º Split Point (crankshaft point).
Split point is self centering and reduces the need for end thrust. Friction at workpiece is reduced.
118º point angles are ideal for use in materials such as mild steel and cast iron.
The 118º point creates easily controlled chips which are wide and thin.
Bright Finish Twist Drills have no surface treatment and are supplied in the as-ground condition.
These tools are suitable for general purpose use, particularly for non-ferrous applications.
Gauge size drill calculations are generally made utilising a reference book or table.
For example, to drill a hole which is 10 thou (thousandth of an inch = .001) bigger than a 1/8? bolt, the user must first work out that 1/8? is 125 thou, so the required hole size is 135 thou. Using a reference table establishes that you would need a number 29.
Number drill bit gauge sizes are analogous to, but different from, American wire gauge.
Number gauge is most commonly used from size 80 (the smallest) to size 1 (the largest) followed by letter gauge size A (the smallest) to size Z (the largest).
Number gauge is actually defined down to size 97, but these smallest sizes are very rarely used.

(2013-28)