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NIMS Drill Press Test
Terms in this set (28)
the majority of material removal operations on a drill press involve
to obtain a clean hole, reduce burring, and prevent drill breakage when the drill starts breaking through the bottom of the work piece, the machinist must
decrease the spindle feed pressure
which type of drill press is used to drill very large pieces?
radial drill press
to drill brass or hard bronze, the machinist often grinds a small flat on the cutting lips of the drill. The flat on the cutting lip provides
a scraping action that prevents binding of the drill
most drills will tend to produce a hole that is
changing the tip angle of a drill is, in most cases, dependent on
what material can be drilled or reamed without any lubrication? (reference machinery handbook)
the feed rate for a twist drill is given in
inches per revolution (IPR)
the speed of a twist drill is given in
revolutions per minute (RPM)
what is the stock allowance for reaming a .3125 inch diameter? (reference machinery handbook)
to ream mild steel with a high-speed steel reamer, the cutting speed should be ________ that of drilling with the same size drill.
a bellmouth condition at the top of a reamed hole may be caused by
a misaligned reamer
the feed rate of a reaming operation is about ________ that of a drilling operation for the same tool diameter
when a reamer gradually starts to cut oversize, a root cause may be
all of the above
(chamfer after cutting edge runout, excessive stock allowance causing material pickup or galling, non-concentric shank, misalignment of the spindles)
which reamer has a back taper?
a high-speed steel twist drill is producing blue chips during a drill operation, which means that the
drill is rotating at an excessive RPM
incorrect drill point angles and clearances will generally produce drilled holes that are
only b and c
(out of round, oversize)
what generally happens when the web thickness is excessive?
the feed pressure is excessive
an excessive lip clearance angle may cause a twist drill to
chip or break out at the cutting edges
a drilling operation is experiencing frequent drill breakage. the twist drill has the proper point geometry, including web thickness and lip clearance angles. a possible solution to the drill breakage problem could be
decrease the feed rate
which of the following parameters affect the final diameter created by a twist drill?
all of the above
(cutting speed, the lubrication applied, the type of material, the way the cutting lips and web are ground)
which of the following may be a root cause of a twist drill that binds in the hole?
only a and c
(the clearance on the margin is worn, the chips are packed in the hole and the flute of the twist drill)
which of the following sets of twist drill are arranged from the largest diameter to the smallest diameter?
7/16, K, C, 18, 78
link to standard drill sizes (chart): http://www.gearhob.com/eng/design/drill_eng.htm
which of the following statements is not a fundamental characteristic of the web?
*note - web is defined as the central portion of the body that joins the lands. the end of the web forms the chisel edge on a two-flute drill
the web stays the same width throughout the whole length of the drill
link to drill bit anatomy: http://www.ctddrill.com/drillAnatomy.php
which of the following included point angles are found on general-purpose twist drills?
the flutes of a twist drill
facilitate chip removal
which of the following statements define the margin of a twist drill?
the cylindrical portion of the land that is not cut away to provide clearance
which of the following statements is not a safe drill press procedure?
having the vise on the right side of the operator
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