Taper Gaging
Taper Plug Gages
Morse, Jarno, Brown & Sharpe and National Machine tapers
Plug gages for checking tapered holes — spindle noses, sockets, sleeves and tooling seats. Each taper standard is ground to its own rate of taper and inspected in our ISO/IEC 17025 accredited laboratory.
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Taper plug gages check the size, angle and contact of an internal taper — the tapered bore in a spindle nose, socket, sleeve or tooling seat. Unlike a cylindrical plug, the fit is judged along the taper rather than at a single diameter, so the gage verifies both the rate of taper and where the mating part seats.
Taper standards we supply
- Morse — the most common machine-tool taper, used in drill presses, lathe tailstocks and spindles.
- Jarno — a simple numbered series where the taper rate stays constant across sizes.
- Brown & Sharpe — a shallower taper long used in milling machine collets and arbors.
- National Machine — the steep taper used where the tool must release cleanly from the spindle.
How they are supplied
Gages are furnished with a certificate of accuracy traceable to NIST. Final inspection is completed in an environmentally controlled ISO/IEC 17025 accredited laboratory. Ring gages for checking the mating external taper are available on the Taper Ring Gages page.