ME 26532 exam 3- drilling and related processes

A spade drill is used for what drilling application?

1' and larger diameter holes in thick material

The point angle is most often ground at a angle of _____ degrees.

118

A point angle of _______ degrees is often used to drill more ductile materials.

135

Drilling makes up about _______ % of all machining operations.

25

What is the name of a drilling machine with multiple spindles that produces multiple holes simultaneously in a work piece?

Multi-spindle drill head

The twist drill was invented in 1863 by whom?

Stephen Morse

What is the most common type of drill bit?

Twist drill

What is the center column or backbone of a twist drill called?

Web

drill bit materials

Yes: carbide inserts, HSS with TiN coating, HSS, solid carbide NOT: HSS with Al2O3 coating

what is the third step in 4 to obtains an accurate hole in a work piece

boring

A gun drill is used for what applications?

drilling deep holes

A hole saw is used for thin materials and can be used to:

drilling holes in thin materials (1/16 and less) drilling a 2" diameter hole through 1" thick plastic drilling a 1-1/8 " diameter hole in sheet metal NOT drilling a blind, 2" diameter hole in steel

The purpose of counter boring is to produce a _____--.

flat bottom recess for a bolt head or nut.

The body of the drill contains two or more helical groves called _______ for chip removal.

flutes

The angles that the flutes make with the center line of the drill is called?

helix angle

During the drilling operations, the drill is guided in the hole by the _____ rubbing against the walls of the hole.

margins

What is the process called where the drill is fed into the work, removed slightly, fed again and the cycle repeated until the hole is finished?

peck drilling

The drill process has a high MRR

true

Statements of the chisel edge of a twist drill:

true: It forms a small hole at the center as part of the drilling operation due to the negative rake angle, it has a high trust force high heat generation has a low cutting speed due to being close to the hole center False: it tends to be self centering

Trepanning

true: it uses less power to operate drill removes a ring of material to produce the hole works well for producing deep holes false: is only used in mass-production operations

reaming process

true: removes a small amount of material from the hole, reaming is a process that can be performed by hand or machinery (mass-production), reaming finishes the hole to an exact diameter NOT: the process will make the hole concentric with an axis of rotation