CH 23 Drilling and Related Processes

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

Web

A spade drill is used for what drilling application?

1" and larger holes in thick materials

The point angle is most often ground at an 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

A hole saw would not be used in which of the following applications?

Drill a blind, 2" diameter hole in steel.

A gun drill is used for what applications?

Drilling deep holes

The body of the drill contains two or more helical gooves call _____ for chip removal.

Flutes

Which of the following is not a material for drill bits?

HSS with Al2O3 coating

The angle that the flutes make with the center line of the drill is called:

Helix angle

Select the statement that is false for the chisel edge of a twist drill.

If tends to be self-centering.

Which of the following statements is false for producing holes by trepanning?

It is used only in mass-production operations.

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

Multispindle Drill Head

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 twist drill was invented in 1863 by whom?

Stephen Morse

Which of the following statements is false for the reaming process?

The process will make the hole concentric with an axis of rotation.

The drill process is has a high MRR.

True

What is the most common type of drill bit?

Twist Drill

What is the 3rd step in the four steps needed to obtain an accurate hole in a workpiece?

boring

The purpose of a counterboring operation is to produce a ____.

flat bottom recess for a bolt head or nut.

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

margins