page_title: Bore gauge
section_title: Telescopic gauges
hierarchical_section_title: Bore gauge / Transfer gauges / Telescopic gauges
context_page_description: A bore gauge is a collective term for the tools that are unique to the process of accurately measuring holes.
context_section_description: These are a range of gauges that are used to measure a bore's size, by transferring the internal dimension to a remote  measuring tool. They are a direct equivalent of inside calipers and require the operator to develop the correct feel to obtain repeatable results.
  The gauges are locked by twisting the knurled end of the handles, this action is performed to exert a small amount of friction on the telescopic portions of the gauge (the smaller diameter rods found at the T head of the gauge). To use, the gauge is inserted at a slight angle to the bore and gently locked to a size slightly larger than the bore while at that angle. Then, rocking the handle side-to-side, slowly move the handle across the bore to the other side. The rocking will first align the gauge with the bore axis and the act of moving the handle to the other side of the bore will bring it to the exact bore diameter. This action compresses the two anvils where they remain locked at the bores dimension after being withdrawn.
  The gauge is then removed and measured with the aid of a micrometer anvil heads, move the head of the gauge around while making the measurement to ensure you get the maximum reading. Grasp the gauge near the head to aid in your maneuvering of the gauge while adjusting the micrometer so it just stops the gauge's motion at one spot only. A bit of practice will quickly give you the idea.
caption: Telescopic gauge set
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