Grinding

Question 1

What are the two major types of grinding?

Answer 1

Offhand grinding (grinder or work piece held by hand).
Precision grinding (includes a variety of operations done to machine work to extremely close tolerances)

Question 2

What are the six basic precision grinding operations?

Answer 2

Cylindrical Grinding
Plunge-cut Grinding
Form Grinding
Internal Grinding
Surface Grinding
Centerless Grinding

Question 3

Explain what grain size is.

Answer 3

The size of the grains of abrasive affect finish, amount of material to be removed.
Basically, grit sizes are determined by screens with mesh openings/inch, i.e.,
30 = a 30 opening/inch grid.
600 = a 600 opening/inch grid.

Question 4

Match each grit to its coarseness.

6–24
30–60
70–180
220–600

fine
coarse
very fine
medium

Answer 4

6–24: coarse
30–60: medium
70–180: fine
220–600: very fine.

Question 5

What is a vitrified bond and what is the advantage?

Answer 5

about 75% of all grinding wheels use a vitrified bond (clay baked in oven — turns to glass)

advantage of the vitrified bond is that it:
* is not affected by oil or water.
* strong, yet releases grains for sharpening

Question 6

What is grade?

Answer 6

the relative strength of the bond and how easily the grains can break away (more
bond—harder the grade.)