Manufacturing Processes Multiple Choice Questions on “Broaching”.
1. What is broaching?
a) A machining process used for increasing the size of the existing hole
b) A machining process used for grinding hardened steel
c) A machining process used for making intricate holes accurately
d) A machining process for removal of a layer of material of desired and depth
Answer: d
Clarification: Broaching is a machining process for removal of a layer of material of desired and depth usually in one stroke by a slander rod or bar type cutter called as, having a series of cutting edges with a gradually increased protrusion.
2. What is the main advantage of broaching over shaping process?
a) Use of single point cutting tool which are inexpensive and can be grounded to any shape
b) Thin or fragile jobs can be conveniently machined because of lower cutting forces
c) Surfaces with obstruction can also be machined
d) Removal of the whole material in one stroke
Answer: d
Clarification: In shaping, attaining full depth requires a number of strokes to remove the material in thin layers step-by-step by gradually infeeding the single point tool. Whereas, broaching enables remove the whole material in just a single stroke by gradually rising teeth of the cutter called broach. Some are the advantages of shaping process and surfaces with obstruction cannot be machined by broaching.
3. For which of the following operations, broaching can be used?
a) Threading
b) Grinding
c) Spline cutting
d) Increasing the size of the existing hole for a certain length
Answer: c
Clarification: Machining by broaching is preferably used for making straight through holes of various forms and sizes of section, internal and external through straight or helical slots or grooves, external surfaces of different shapes, teeth of external and internal splines and small spur gears.
4. Why push type broaches are made shorter in length?
a) To reduce machining time
b) To increase the efficiency
c) For easy handling of the tool
d) To avoid buckling
Answer: d
Clarification: Both pull and push type broaches are made in the form of slander rod or bar of varying section having along its length one or more rows of cutting teeth with increasing . Also very high forces are generated during the machining. Therefore, push type broaches are made shorter in length to avoid buckling as they are subjected to compressive load.
5. Why chip breakers are provided on the broach?
a) To reduce machining time.
b) To increase the cutting force by breaking the chips
c) To reduce the friction between tool surface and the workpiece by breaking the chips
d) To break up the wide curling chips
Answer: d
Clarification: Small in-built chip breakers are alternately provided on the roughing teeth of the broaching to break up the wide curling chips and thus preventing them from clogging and increasing force and tool wear. Ductile materials need wider and frequent chip breakers.
6. Why neck section provided in the pull type broaches are made shorter in diameter?
a) To provide better surface finish
b) To remove chips easily
c) To allow failure in case of overloading
d) For holding purpose
Answer: c
Clarification: Neck is one of the essential elements of the broach. Smaller diameter means higher stress concentration. Therefore, in case of overloading neck section will fail first and while keeping the workpiece safe.
7. In broaching, generally the broach remains fixed and the workpiece travels providing cutting velocity.
a) True
b) False
Answer: b
Clarification: In broaching, the workpiece remains stationary throughout the process and the broach travels with the cutting velocity. The broach is also provided with small chip breakers to break up the chips.
8. How many types of broaches are there?
a) 3
b) 5
c) 8
d) 9
Answer: d
Clarification: Various types of broaches have been developed and are used for a wide range of applications. Types of broaches are as follows,
(1) Pull type (2) Push type (3) Ordinary cut type (4) Progressive cut type
(5) Solid type (6) Sectional type (7) Modular type (8) Profile sharpened type
(9) Form relieved type.
9. Which of the following broaches are re-sharpened by grinding at rake faces?
a) Form relieved type
b) Modular type
c) Profile sharpened type
d) Sectional type
Answer: a
Clarification: Form relieved type broaches are sharpened and re-sharpened by grinding at their rake faces. These broaches have more complex cutting edge geometry and varies point-to-point along the cutting edges. Here the product is the replica of the tool form.
10. Which of the following type of broaches are sharpened or re-sharpened by grinding at the flank surfaces?
a) Profile sharpened type
b) Sectional type
c) Segmented type
d) Ordinary cut type
Answer: a
Clarification: Profile sharpened type broaches are sharpened or re-sharpened by grinding at the flank surfaces. These cutters have simple geometry with same rake and clearance angles all over the cutting edge. These broaches are generally designed and used for machining flat surfaces or circular holes.