21December 2021
this is a portable drill this one has a cord you
have to plug into an electrical supply cordless models use their own internal batteries when
you can't bring the work to the drill you can take this drill to the work but don't expect
it to put large holes through very hard metal the biggest drill bit that'll fit in the Chuck
here is usually marked on the body of the drill along with the speeds at which it turns there
are usually two speeds but some drills can be set to any speed within their range a bench
mounted drill allows accurate drilling with more control more so than a portable drill
which is convenient but can be difficult to guide accurately a mounted drill can feed the
drill bit at a controlled rate and the work table secures the job at a constant angle to the
drill bit also this drill can be set to run at different drilling speeds this drill chuck
takes bits up to 13 millimeters in diameter drill-bits come in many closely-spaced sizes the
most common is the twist drill it has a point and a body usually with two spiral grooves and it's
shank is gripped in the jaws of the drill Chuck a Morse taper is a system for securing drills
Morse taper size changes according to drill size the shank of the drill bit is tapered
and it fits snugly into the drill spindle which has a similar taper this tang is also
located in the spindle and it drives the drill it's a quick way to change drills
without constantly adjusting the Chuck when there's already a hole drilled
in sheet metal that needs enlarging a multi fluted tapered hole drill will do
the job in about the same time it takes to say it a drilling speed chart should
be kept near the bench or pedestal drill it compares drill sizes and metals to show
the proper speed so to drill a 10 millimeter hole through this piece of aluminium the
drill speed should be 1,800 revs per minute
