ROK-IT Spherical Bore Plug Gages

ROK-IT Spherical plug gages -No jamming or swelling in the bore – If the ‘GO’ end rocks over centre and the ‘NOGO’ stops, the bore is within tolerance. Fast and simple.
Exceptional gauge life – less friction means less wear. Single Ended or Double ended gage. Versatility – Instantly reveals conditions of ovality, barrelling and taper. Even back taper in a blind bore. 80$lighter – No unnecessary metal so you can use with ease of effort.

ROK-IT gauges can be purchased as either double ended ‘GO’ and ‘NOGO’ with a standard 100mm ( 4in ) handle, or in the larger diameters often with single ended handles also 100mm long.
ROK-IT gauges below 16mm ( 0.630 in ) diameter are supplied with a ‘taperlock’ design handle, giving an effective length of 90mm ( 3 1/2 in )
If the bore is very long we can supply an articulated ‘deep bore’ handle to the length required.
ROK-IT gauges over 300mm ( 12 ins ) in diameter will be supplied in the single ended design, but with two handles equi-spaced for ease of use.

hen ordering, please provide:

  • Tolerances, e.g. GO—3.500”/NO GO 3.501”.
  • Class required: e.g. XX, X, Y, Z.
  • Gage design: e.g. Whether single ended or double ended; For deep bore model specify length of parallel rods (allow approx. 3” for handling).
  • Special marking required on gage, e.g. any code which you may wish to imprint, space permitting.
  • Single ended gages—Do you want “GO” or “NO GO”.

At no extra charge:

  • All metric sizes
  • Handles etched with size only
  • Extra charge for additional etchings
  • Gage handles

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ROK-IT bore gage offers spherical form which eliminates the limitations the use of a plain cylindrical plug gage. 

  • RC-63 Hardened steel
  • Gages to finer limits: 30 to 50 X greater life: Gages entire bore surface (line contact instead of point contact)
  • Gage cannot jam in bore
  • Can be used as an approach gage
  • Can check recesses
  • Enters bore from any angle
  • Gage in 1/5th the time
  • Checks shallow counterbores and blind holes
  • Little or no skill required

Click below to Download the ROK-IT Spherical Bore Gage ordering information



  • It will positively “accept” or “reject” down to the finest limits.
  • It is extremely light and easy to handle.
  • 4” diameter double ended gage weighs 1 lb.
  • A blind operator can inspect bores with ROK-IT.
  • It is not possible for the gage to seize or jam in the work.
  • Gages can enter bore at angles as in the case of a component in a machine where quill is in the way.
  • It reveals back taper in blind bores. ROK-IT gages work without having to line up gage perpendicular to bore. Hence it is self centering.
  • ROK-IT gages are easily and quickly inspected with “Supermike” or any comparator (use flat anvil only).

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