Master Ball Sets

Master Ball SetsMaster Ball Sets
Master Balls are made of the finest grade tungsten carbide and are therefore highly resistant to corrosion, humidity and abrasion. Size and sphericity tolerances are held to 0.000010″ and are certified to the National Institute of Standards and Technologies.  All Master Balls are widely used in gage and tool rooms, and in inspection and production departments engaged in close-tolerance measurements.

APPLICATION: Calibration of O.D./I.D. gages and compactors
Checking flatness and parallelism
Measure the depth, internal taper and diameter
SIZES: English: 1/16″ through 1″ in 1/32″ increments (31 balls/set)
Metric: 1mm through 25mm in 1mm increments (25 balls/set)
MATERIAL: Tungsten Carbide
Diameter tolerance:
Micro finish:
+/- .000010
1 micro
RA 88-92
+/- .3 Microns (.000012″)
.2 Microns (.000008″)
.02 Micron RMS (.8″)
RA 88-92


  1. Can be sold individually or in sets
  2. Balls/Sets are certified and traceable to National Institute of Standards and Technologies masters.
  3. Recalibration and certifications with charts are available on an individual or a set basis
  4. Both sets and individual master balls/recalibrated on a routine basis.