ISO 7.2 Gauge No.4

This gauge is a 1:16 taper plain ring gauge and is suitable for checking the major diameter and the related useful thread length of taper external (R) threads. The gauge incorporates a step equal to the total tolerance (AS ISO 7.2 – 2008 p8).

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

NATA Calibration – ISO 17025
Storage case for a single gauge or for a gauge set
Full range of gauges for ISO 7.2 available

Applicable standards

AS ISO 7.2 – 2008 Pipe threads where pressure-tight joints are made on the threads. Note previous standard was AS 1722 Part 1 – 1975, also previously referred to a BSPT.

Why this product is used

Tapered plain ring gauges are an efficient way to check tapered external diameters for conformance. Simply apply the gauge to the part by hand until it stops. If the end face of the part is between the max. and min. steps this condition indicates a conforming part.

  • 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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Thread type Range in stock Range manufactured
ISO 7 – No. 4 1/8” - 4” 1/8” - 6”


Is BSPT still a current standard?

No, the current standard is ISO 7.

BSPT was replaced by AS1722 Part 1, then AS1722 Part 1 was replaced by ISO 7.

Is AS1722 Part 1 the same as ISO 7?

It is very close but there are some variations, call us for more detail.

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.

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

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