APR Deluxe AN Bolt Gauge | DANBG

Aero Products Research


Sale price $7.16 Regular price $8.95

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APR Deluxe AN Bolt Gauge | DANBG

Pocket size stows easily in flight case or toolbox!

APR’s innovative combination AN BOLT GAUGE and 388 quick CONVERSION SCALES with rulers is a must for pilots, mechanics, aircraft owners, and anyone who uses AN Bolt hardware. This pocket-size tool is manufactured with high-stress vinyl and is the only AN Bolt Gauge combined with conversion scales and rulers.

APR's color-coded AN Bolt Gauge accurately measures AN Bolt sizes from 3/16” to ½” in diameter and up to 8” in length. Graphic instructions eliminate errors to help you quickly determine the correct bolt size.

The conversion scales list fractions in increments of 1/6” from 0 to 1 inch (64 entries). Parallel to each fraction are the decimal and millimeter equivalents. The bottom of the conversion scale shows the mathematical formulae for conversions in one thousands of an inch in millimeters to inches, and inches to millimeters. Precision 8” and 20.5 centimeter rulers are included on the sides of the bolt gauge.


  • Fractions to Decimals
  • Fractions to Millimeters
  • Decimals to Fractions
  • Decimals to Millimeters
  • Millimeters to Fractions
  • Millimeters to Decimals