RG 750 Radius Gauges

The  RG 750 Radius Gauges are a smaller version of the RG 3600’s. They measure any curvature with a radius from 2.5″(64mm) to 30″(750mm). The short distance between the outer contact points (5″ for the IRG 750 & 6″ for the ORG 750), means shorter arc-length for roll & bump-roll test radius and of course all those smaller jobs where the RG 3600’s won’t fit.

The measuring tolerance of the RG 750 gauges is +/- .5% for all measurements. In most cases this is only suitable as a reference measurement. The RG 750 gauges are NOT recognized by any international standards organization. There is no calibration certificate for the RG 750 radius gauges. All gauges are tested and adjusted to a maximum tolerance of +/- .5% on all measurements before leaving the factory.

Arc Master Radius Gauges should be used for REFERENCE only. They are NOT registered with any Industry Standards Organization.

IMPORTANT: What you should do when you first receive your radius gauge.

To ensure proper calibration of your radius gauge, we recommend that at first use, check the gauge on a sample arc and record the measurement. This sample arc should have a radius of 20” or larger. The larger the radius sample your gauge is checked on, the more accurate the check. Make a note of the radius measurement on the sample arc and refer to this sample arc for all your regular radius checks.

(The RG 750 Radius Gauges do not come with the Variable Arc.)

IRG 750


                         from 2.5”(64mm) to 30”(750mm) in Metric & Imperial.


It works the same way as the IRG-3600, but on a smaller scale.

There are no arms to unfurl to take your measurement. The IRG-750 stores as you see it here, ready for use.

Also, there is no locking knob. We added what we call “Sliding Tension” into the gauge. The IRG-750’s smooth action still makes it easy to take a quick measurement, but it will more readily hold its reading afterwards.  Watch the IRG 750 video for a demonstration.

Measure rolled pipe, plate, angles, bump-rolled metal sheet & plate, complex contours, wooden arcs, etc…



ORG 750

The   ORG-750 MEASURES ANY OUTSIDE RADIUS from 2.5”(64mm) to 30”(750mm) in Metric & Imperial.

It works the same way as the ORG-3600, but on a smaller scale.

The ORG-750 has the same features as the IRG-750 but measures the OUTSIDE of an arc. These gauges compliment the 3600’s because they require such a short arc length to obtain a radius measurement.

Both of these gauges are made of 5052 Aluminum and can easily achieve an accuracy of +/- 0.5% on all radius measurements. At 12”(300mm) that would be +/- .06”, 1/16”(1.5mm).

The 750’s Best feature is its price. As opposed to the $1000 plus you’d pay for a digital radius gauge, Arc Master Radius Gauges are inexpensive enough and so useful, you’ll wonder how you ever managed without them. Watch the ORG 750 video for a demonstration.