metal removal

Question 1

milling?

Answer 1

The milling is a metal removal operation by means of a multi-point rotary cutter attached to the machine spindle which advances in the material fixed on the machine bed. In this operation, the cutter takes the cutting motion and the workpiece usually takes the feed motion. Milling is typically used to produce parts that are not axially symmetric and have many features, such as holes, slots, pockets, and even three dimensional surface contours.

Question 2

metal cutting parameters?

Answer 2

• relative motion between tool and workpiece
• shape of tool
• material of tool and work piece

Question 3

feed?

Answer 3

relative motion of tool in turning on miiling machines

Question 4

speed?

Answer 4

rotation of object in RPM.

speed=N*pie*Do

N= spindle speed

Question 5

depth of cut?

Answer 5

Do -D_F /2

Question 6

+ve rake?

Answer 6

 Sharp & pointed tool  HSS are given +ve rake angle  Low strength materials  Not preferred for high speed operations

Question 7

-ve rake?

Answer 7

 Greater tool strength  Enhances surface finish  Carbide tools are given –ve rake angles Usually for high speed cutting

Question 8

turning?

Answer 8

• center lathe machine
• work piece in chuck
• tool in tool post
• tail stock to hold work piece
• feed is cross or longitudinal
• single point

Question 9

facing?

Answer 9

• cross feed
• Removing metal from the end of the workpiece to produce a flat surface perpendicular to the axis of the machine.
• single point

Question 10

drilling?

Answer 10

• tool is fixed to tail stock
• longitudinal feed
• multipoint
• Making a hole

Question 11

counter sinking?

Answer 11

• longitudinal feed
• single point
• to make an entrance for the drill bit

Question 12

tapering?

Answer 12

• To make a conical shape
• single point
• longitudinal
• tanx=D₁ - D₂ /2L

Question 13

boring?

Answer 13

• longitudinal
• single point
• to increase a hole’s diameter

Question 14

inner threading?

Answer 14

• To make an inner threading for a nut to be assembled with a screw.
• longitudinal
• single point

Question 15

chamfering?

Answer 15

• To convert sharp edges to an angular shapes
• vertical milling machine
• longitudinal
• multipoint

Question 16

undercut?

Answer 16

• cross
• To decrease the diameter of a certain part at the middle of the WP.
• single point

Question 17

cutoff?

Answer 17

• cross
• To cut the product from a shaft.
• single point

Question 18

knurling?

Answer 18

• cross
• To make criss-cross shapes.
• random point

Question 19

up/conventional milling?

Answer 19

• tool cuts to the right
• feed is to the left
• high force
• bad surface finish and tool life
• gears and slots at low cost

Question 20

climb milling?

Answer 20

• cutting and feed have same direction
• cutting is counterclockwise
• for large objects

Question 21

counter boring?

Answer 21

• Impression to accommodate the head of the screw.
• single point
  *

Question 22

counter sinking?

Answer 22

• To make an entrance for the drill bit
• single point

Question 23

reaming?

Answer 23

• Finishing holes with standard diameters
• multipoint

Question 24

tapping?

Answer 24

• In case of inner threading inside a hole.
• multipoint

Question 25

broaching?

Answer 25

• linear motion
• for complex cuts

Question 26

grinding?

Answer 26

• removing thin layer
• tool: grinding wheel
• used for its accuracy, great surface finish and machining complex cutoffs

Question 27

abrasive type?

Answer 27

• coarce=big
• fine = small

Question 28

grain size?

Answer 28

• small amount of particles = rough object
• big amount of particles = fine obj.

Question 29

grade?

Answer 29

• abc= soft
• xyz= hard