Abstract: A tungsten carbide surface is finished to an RMS surface roughness of about 25 nm (1.0 microinch) or less by abrasion using diamond grit particles. The tungsten carbide surface is abraded by a sequence of grit particle-containing abrasive members, such as abrasive films, pastes, or slurries, at least one of the members having an average grit particle diameter of about 2 &mgr;m or less. The finish is enhanced by oscillating the abrasive member back and forth over the tungsten carbide surface. A different speed is used for at least two consecutive films in the series, thereby generating scratches at different angles which can be distinguished. A superfinish, corresponding to a lack of visible scratches at 100× magnification, can be obtained by abrading the tungsten carbide surface with a diamond slurry or paste having grit particles with an average diameter of about 1 &mgr;m or less.

Abstract: A tungsten carbide surface is finished to an RMS surface roughness of about 25 nm (1.0 microinch) or less by abrasion using diamond grit particles. The tungsten carbide surface is abraded by a sequence of grit particle-containing abrasive members, such as abrasive films, pastes, or slurries, at least one of the members having an average grit particle diameter of about 2 .mu.m or less. The finish is enhanced by oscillating the abrasive member back and forth over the tungsten carbide surface. A different speed is used for at least two consecutive films in the series, thereby generating scratches at different angles which can be distinguished. A superfinish, corresponding to a lack of visible scratches at 100X magnification, can be obtained by abrading the tungsten carbide surface with a diamond slurry or paste having grit particles with an average diameter of about 1 .mu.m or less.

Abstract: A corner roller tape tension enhancer assembly for use with a corner roller in a belt driven magnetic tape cartridge. The assembly comprises a cylindrical corner roller having an outer wall for contact with a drive belt and an inner wall suitable for mounting the corner roller on an axial mounting structure. The assembly also comprises a fatigue resistant metal spring positioned against a portion of the corner roller for controlling magnetic tape tension and to produce a uniform tape tension with respect to drive force over a wide speed range.