Drill bit sizes are
written as irreducible fractions
. So, instead of 78/64 inch, or
1 14/64 inch, the size is noted
as 1 7/32 inch. Below is a cart
providing the decimal-fraction
equivalents that are most relevant
to fractional-inch drill bit sizes
(that is, 0 to 1 by 64ths). (Decimal places for .
If you know the size of the screw,
you can locate the size of the
drill bit by looking at the opposite
end from the sharp point of the bit.
It's likely engraved there.
Standard metric sizes are
defined in ISO 2936:2014
"Assembly tools for screws and nuts
—Hexagon socket screw keys", also
known as DIN 911. The full set of
defined sizes are: 0.7 mm, 0.9 mm,
1.3 mm. 1.5 to 5 mm in 0.5 mm increments.
They're great for being able to
be quickly swapped out if you
an adapter, and even without an
adapter that hex shank is a lot easier
for your drill chuck to grab onto when
using very small bits like 1/16”
& smaller.
You'll see a list of numbers from
to 10 or 20. These are used to
set the clutch to deliver a torque range.
The higher the number on the collar,
the higher the torque and the larger the
fastener that can be driven.
To adjust your clutch, align the
arrow to a lower setting and start
driving a screw.
Take a loose screw and
compare it to the size of
the bit you need to use,
using the screw's core rather
than its flute. A bit that is very
slightly smaller than the screw
will ensure a proper fit. Choosing
a bit that is too small means that
the screw will get stuck so take care
to choose carefully.
In hex, four digits of a binary
number can be represented by
a single hex digit. Dividing a
binary number into 4-bit sets
means that each set can have
a possible value of between 0000
and 1111, allowing 16 number
combinations from 0 to 15. With
the base value as 16, the maximum
value of a digit is 15.
