Using a bar gauge lets you directly transfer and compare dimensions without conversion to numbers, reducing the chance of transcription errors. You can even use it to quickly test an assembly for squareness by checking that the diagonals are equal.
The base unit consists of two 6" steel rods fixed to aluminum clamp heads. The rods have threaded end holes that accept interchangeable brass tips or extension rods.
Three styles of tips are included: ball tips for inside measurements (the rounded ends avoid marring softwood), pointed tips for inside corner measurements and 13/16" diameter mushroom-shaped tips to hook over edges for outside measurements. The distance between the ends of the round or pointed tips is equal to the distance between the inside faces of the mushroom-shaped tips, letting you convert an inside measurement to an outside measurement just by switching tips. The clamp heads have large thumbscrews and slide easily for quick adjustment. The base unit adjusts from 7 1/2" to 12". Two pairs of extension rods are included, 4" and 12", allowing a span up to 44". For greater reach, additional 12" extension rods are available separately.
A 1 3/8" diameter mushroom-shaped tip is also available separately. It provides a larger reference face when hooking over edges for outside measurements but is reversible for inside measurements.
A fast, reliable way to get a true measurement. Made in Canada.