Tungsten carbide Ball Plug Gages are quick and easy to use because they can be inserted at any angle. "Go" gages go freely and "no go" gages won't bind. They are particularly effective for giving a feel for bell-mouth, barrel or taper problems. These gages are widely used for spherical seat and bearing race "go" and "no go" gages.
Ball gages are available in 4,550+ sizes from 1.050” in 0.0001” increments.  Custom length stems are available both straight and with bends. GD also has the capability to braze gage balls to stranded wire cable.
GD standard gages feature polished tungsten carbide balls available in four tolerance classes which are mounted on stainless steel shanks.  GD offers both single and double ended ball gages, with or without handles.  For convenience defining your requirements, the following files are available: Single ended no handle, Single ended with handle, Double-ended with handle.  Please contact GD if you have questions or send the completed form for a quote.

APPLICATION:
Gage hole sizes
Identify ball-mouth, barrel, or taper conditions of a hole
Measuring radius accuracy
Determine true radius
Measure pitch diameters
Measure hole center distances
I.D. and O.D. gaging
Radius to face measurements
Calibiration of mechanical calipers
STANDARD SIZES: 0500 - .750" diameter

MATERIAL:
Balls - tungsten carbide
Stems - 316 stainless steel or tool steel
Handles - aluminum; colored - red/silver/green
Bushing - brass/bronze

The GO Ball Plug Gage is able to pass inside the bore diameter, and has a positive unilateral tolerance. If the proper GO Ball Plug Gage is used and does not pass into bore diameter, then the bore is not yet within specification.
The NO-GO Ball Plug Gage is not able to pass inside the specified bore tolerance and has a negative unilateral tolerance its self. If the NO-GO Ball Plug Gage is able to pass into the bore diameter, the bore diameter is past its specified tolerance. Referance: American Gage Society Standard Tolerances