How is drill poress size determined
by the largest diameter circular piece that can be drilled on center.
The spiral grooves in a drill body are used to
help form the cutting edge of the drill point; curl chips for easier removal; and, form channels through which the chips can escape from the hole.
Name the device employed to enlarage a taper shank drill so that it will fit the spindle opening.
The device used to permit a drill with a taper shank too large to fit the spindle opening is called a(n)
Cutting compounds or fluids are used to
cool the drill; improve the finish of a drilled hole; and, aid in the removal of chips.
List the three factors that must be considered when repointing a drill
lip clearance; length and angle of the lip; and proper location of the dead center.
What occurs when the cutting lips of a drill are not sharpened to the same lengths
the hole is larger than the drill and the drill and the drill press are strained.
The __________ should be used frequently when sharpening to ensure a correctly sharpened drill
drill point gage.
Large drills require a considerable amount of power and pressure to get started. They also have a tendency to drift off center. These conditions can be minimized by first drilling a __________ hole. This hole should be as large as, or slightly larger than, the width of the __________ of the drill point
pilot and dead center.
How is the depth of a drilled hole measured
using a drill press mounted with a depth stop or a depth gage.
The __________ is almost identical to the hand reamer except that the shank has been designed for machine use
A __________ expansion reamer provides rigidity and accuracy not possible with conventional expansion reamers.
How should a reamer be removed from a finished hole
remove the reamer from the hole before stopping the machine.
The cutting speed for a high-speed reamer is approximately __________ that for a similar - size drill
What is the name of the operation employed to cut a chamfer in a shole to receive a flat-head screw
__________ is the operation that machines a circular spot on a rough surface for the head of a bolt or nut
Name the following parts of a drill
margin, cutting lip, chisel edge/dead center, web, tang, shank body, and flutes.
What is a through hole
a hole that is drilled, reamed, milled, etc., completely through the substrate.
Common operations with a drill press
counterbore, countersink, reaming, spotfacing, tapping, drilling, boring...
Why is a hole counterbored
to enlarge the drilled hole to the proper depth and machine a square shoulder on the bottom to secure maximum clampong action from the fastener.
What should be done prior to tapping, and why
chamfering. It prevents burrs from fouling the tap. The die should be 1/32nd larger than the tap.
What else should a machinist do prior to drilling
look at the drill for flaws, measure, check the shank.