Glass grinding bit

A glass grinding bit, comprising:

• a generally tubular, monolithic plastic body having a first end, a second end, a central longitudinal axis and a tubular wall;
• an outer surface formed as part of said body in alignment with said longitudinal axis and defining an outer surface of said tubular wall;
• an interior blind cavity formed as part of said body in alignment with said longitudinal axis and in concentric relationship with said tubular wall outer surface, said cavity defining an inner surface of said tubular wall that is spaced from said tubular wall outer surface;
• an apertured bore-defining structure extending inwardly from said tubular wall and terminating at a central bore disposed in alignment with said longitudinal axis for receiving a drive shaft;
• a grinding sleeve on said tubular wall outer surface;
• said grinding sleeve having an inner surface in permanent interfacial contact with said tubular wall outer surface and an abrasive outer grinding surface;
• a threaded bore in said body extending transversely from said tubular wall outer surface to said central bore;
• and
• a set screw in said transverse bore for securing said grinding bit to a drive shaft.

A collection of glass grinding bits, each comprising:

• a generally cylindrical, monolithic plastic body having a first end, a second end and a central longitudinal axis;
• a central bore formed as part of said body in alignment with said longitudinal axis for receiving a drive shaft;
• an outer surface formed as part of said body in alignment with said longitudinal axis and in concentric relationship with said central bore;
• a grinding sleeve on said body outer surface;
• said grinding sleeve having an inner surface in permanent interfacial contact with said body outer surface and an abrasive outer grinding surface having a characteristic surface roughness;
• a threaded bore in said body extending transversely from said body outer surface to said central bore;
• and
• a set screw in said transverse bore for securing said grinding bit to a drive shaft;
• and further wherein said body of each of said grinding bits of said collection is transparent or translucent, and comprises a colored plastic whose color is different from the color of other grinding bits of said collection and which signifies the characteristic surface roughness of the outer grinding sleeve associated with said grinding bit.