The Keyway Tri-Gauge fills the need for a measuring device that accurately and efficiently measures the geometry of keyways in shafts.

  • Replaces expensive coordinate measuring machines and granite tables with height gauges
  • Provides greater accuracy and speed
  • Lightweight – can be used on production line, on skids
  • Adapts to inches or millimeters

Use on Shafts from ½” to 6″ in diameter for standard keyways

  • Large gauge available for 6″-16″
  • Two styles for Woodruff keyways
  • Custom gauge for shafts under ½”

Investment on Return on Your First Job – Saves on Scrap, Time and Money

Easy to Use – Train in minutes. Accuracy within .0005″ or .01 mm

Keyway Tri-Gauge will improve the quality of your keyways.

U.S. Patent # 4,970,799
U.S. Patent # 5,131,160 (Foreign patent # 2894825)

Only Gauge to Measure Centering, Parallelism and Perpendicularity
in one Setting of Measurements


Measures Centering of Keyway to Centerline of Shaft


Measures Parallelism of Keyway to Shaft of Centerline


Measures Perpendicularity of Keyway Side Walls to Base of Keyway

Digital readout available

Visit Trace-A-Matic Corp. for great turning & milling services.
Visit American Friction Welding, one of the largest job shops in the US.
Visit D&H Industries for precision stamping.

- Satisfied Customers -

Hi John,

We’ve been using the Tri-Gauge for about a month …I’ve conducted three training sessions.

The people that have used it are amazed with its simplicity…one man wanted to know why we didn’t buy it 10 years ago…another person mentioned that they were able to check parts without tearing down their setup.

We’re having fun.

Bill Ely

Century Specialties
Traverse City, MI

From a volume manufacturer of high-quality motors supporting the machine tool industry:

Hello at Tri-gauge. The Tri-gauge arrived in perfect condition and on time. We have since used it extensively. Apart from there being minimal setup time the big benefit is you do not have to set up on a surface table, insert gauge blocks etc.

We have been able to go into the store and check shafts in situ. We have a lot of shafts that have been quarantined and the gauge has enabled us to check them without disturbing our processes and clogging up our area. We have checked the gauge against our first principle check and found very close correlation.

We are very pleased with your device.

Best regards,

Martin Harper

SEM Controled Motor Technology
United Kingdom