Tapered Plain Plug Gauges

S.G. Prittie manufactures a range of tapered plain plug gauges to Australian and International Standards. We stock a range of standard tapered plugs to suit pipe threads, machine tapers and a range of medical gauges. Special gauges are also available as made to order gauges. All of our gauges are made from hardened tool steel to ensure long life and are supplied with a manufacturers certificate of conformance (COC).

Product options

Design to suit your product
Grade 420 stainless steel – Medical gauges
Special blank dimensions available
NATA Calibration – ISO 17025
Storage case for a single gauge or for a gauge set

Applicable standards


Why this product is used

Tapered plain plug gauges are used to check diameter at a reference length. Steps on the gauge indicate a tolerance band. If the end face of the part is between the max. and min. steps this condition indicates a conforming part.

Tapered plain plug gauges are also used as “blueing gauges”. This process involves applying dye to the tapered part of the bore, then apply the plug gauge and gently rotate. Remove the plug and check the contact pattern. The bore taper is adjusted to match the plug gauge.

  • Customisation

    Customisation is offered on most gauges. We can add a new feature to a standard gauge, manufacture a revised design based on a standard gauge, or design a new gauge to suit your application.

  • Support

    We offer design and technical support for all our gauges, as well as support for measurement and calibration inquiries. Contact us via phone or email.

  • Delivery

    We offer express or economy delivery and can send products to local, interstate and overseas locations. We’re also happy to use your own delivery supplier.

  • Manufacturing

    We are an Australian business located in Airport West Victoria. Quality is a priority and we have ISO 9001 and ISO 17025 management systems in place.


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Gauge Type Range Available Range Stocked
ISO 5356/1 8.5, 11.5, 15, 22, 23 & 30 Made to order
ISO 594/1 Made to order Made to order
NPTF 1/16” – 4.0” Made to order
Morse Taper No.2 – No.5 Made to order
Machine taper NT30 – NT50 Made to order


How often do I need to calibrate my gauge?

There is no fixed time, calibration frequency is based on how often the gauge is used and the conditions that the gauge is exposed to. Frequent use and abrasive materials will require more frequent calibration, low use in a clean environment will allow less frequent calibration. Usually the user determines the calibration frequency.

Can a gauge be made to my own specification?

Yes, we can design special plain ring gauges for your manufacturing process.

If you need assistance selecting the correct gauge or have technical questions please contact us.

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