Review - Planer Gage

Planer Gage - What Is It Good For?

[April 1, 2016]

Many people consider the planer gage to be an obsolete tool with no practical use in today's machine shop. In fact they are still made today, although they can also often be picked up at a bargain price at a flea market, garage sale, or other places used tooling is sold. The planer gage was originally intended to be used to set the cutter height on a metalworking planer or shaper (here is the Starret patent from 1916), but it has many other uses.

This photo shows a planer gage I picked up at an estate sale for $20 (Sept. 2015).

Starret refers to this gage as a Universal Precision Gage No. 995 - this nomenclature recognizes the fact that the gage has many uses beyond its original intent. It is distinguished from "basic" planar gages by the inclusion of the following:

Fitted wooden case
1" extension
3" extension
Fine adjust mechanism
Scriber with holder
Offset attachment

This gage is also referred to by some as a "master planer gage." This comment from Hugo F. Pusep (writing in American Machinist, 1916, pp. 1131) is applicable not only to the planer gage, but likely to many other tools as well:

It is often the case that a tool, because of its simplicity and because it was originally made for a single purpose, is used for nothing else - not because it lacks adaptability, but simply because no one thinks of other applications.

Uses

Here are a few if the applications which people have found for this tool:

Setting cutter height on a (metal) planer or shaper - the original use and hence the name
Adjustable parallel
Square
Level
Height gage
Measuring dovetails
Measuring slot width
Setting tool height
Transferring measurements
Scribing on a surface plate (some models)
Stabilizing work set-ups (some people would argue that this is not a good use for a precision tool)
Setting a sine bar

Links

L.S. Starret patent : download the PDF
The Planer Gage and its Uses : [Google Books - American Machinist, Volume 45, Issues 14-26, Dec. 28 1916, pp. 1138] Discusses multiple uses for set up, measuring, etc.
Planer Gages : [Video] Oxtoolco discuses planer gages and their uses.
Planer gauge tune up : [Video] Shadon HKW shows how to inspect and refurbish a planar gage.
Setting a planer gage : Forum discussion and Lufkin instructions for setting a planer gage.
Stability in setups : [Google Books - CNC Trade Secrets by James A. Harvey, pp. 18] Illustrates use of a planer gage as a kind of machinists jack to stabilize a milling setup.
Universal precision Gage No. 995 : [PDF] See page 18 of this Starret catalog for a description and illustration of uses.