Radius gauges vary not only size but also in cut out designs. The differing layout is necessary to incorporate the varying size concave and convex curves.
Radius gauge sets allow you to measure between a set range in metric (mm) or imperial (fractional inch).
Multi-function blades have a centrally inscribed measurement. This refers to both the internal (concave) and external (convex) radius.
Likewise, single function blades have a centrally inscribed measurement. However, this refers to the single radius at the end of the blade. EIther concave or convex depending on the blade.
Common metric gauges provide measuring ranges from: (0.75 – 5 millimetres) 18 blades with 0.25 millimetre increments. Or (5.5 – 13 millimetres) 16 blades with 0.5 millimetre increments
Common imperial gauges provide a measurement range from: 17/62 – 33/64 inches, 16 blades with 1/64 inch increments. Or 1/32 – 1/4 Inches, 15 blades with 1/64 inch increments.
Individual blades can be bought as part of an assorted range. Blade assortments can contain around 25 pieces. 1/64 -17/64 inches in 1/64 increments with 9/32 -1/2 inch by 1/32 increments. Or 0.5 -13mm in 0.5 mm increments. Assortments such as this often come with a gauge holder.
Individual blades usually come with one set size, where all cut-outs around the edges of the blade refer to one measurement. However, some individual blades contain cut-outs with different measurements. It is important to check the inscribed measurements for this reason.
Guitar radius gauges measure the curvature of a guitar fretboard. The radii of guitar strings varies ranging from 7.25 inches (184.1mm) -16 inches (406mm). The size of a guitar fretboard varies according to the manufacturer.