Your Cart

Rob Cosman's Mortise & Tenon Attachment

Rob Cosman's Mortise & Tenon Attachment
  • Rob Cosman's Mortise & Tenon Attachment
  • <iframe width="640" height="360" src="" title="Mortise Gauge 2022" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
  • Rob Cosman's Mortise & Tenon Attachment
  • Rob Cosman's Mortise & Tenon Attachment

Rob Cosman's Mortise & Tenon Attachment

Regular price $0.00 USD $99.00 USD Sale

23 left in stock.
Full Description
Customer Reviews

My mortise gauge attachment easily fits into the body of my Rob Cosman Marking Gauge,  my "Cosmanized" Woodriver Marking Gauge, and most other marking gauges that use a 5/16 inch diameter rod.  

  • Designed for marking out a mortise & tenon joint in furniture making.
  • Width range between the two cutters: 3/16 inch to 11/16 inch wide.
  • Works best for marking out cuts between 1/4 inch to 5/8 inch wide.
  • Designed primarily for marking out the tenons but works for the mortises as well.
  • Place your mortise chisel between the cutters, snug up the cutters to the chisel sides, using the knurled handle lock the cutters in place, remove the chisel.  Now your gauge perfectly matches the width of your chisel.
  • When laying out tenons, the bevel / waste side of the gauge is perfectly located on the "waste" side of the line.
  • When laying out mortises, the bevel / waste side of the cutter is located on the "keep" side of the line.
  • Rob recommends laying out the mortise using just one line with a standard marking gauge, instead of this gauge.  The reason for this is it is much easier to register your mortise chisel to one line verses two lines when chopping.  
  • A brass knurled locking handle

  • An O-1 hardened cutter.


Customer Reviews

Based on 5 reviews
Richard Schweim
easy layout

worked brilliantly, was very pleased with the results of my first mortise and tenon joint entirely by hand.

James Ramsey
Best ever !!!

Terrific I really appreciate it how sharp it is, I also really like the weather micro adjuster sticks out the front to be used as the second handles added stability really good job you guys thanks Jamie

Carlos Alberto
Mortise Gauge Attachment

Very happy with the mortise gauge attachment. Works as one would expect a tool from Rob Cosman should work.

Perfect for my needs

I only have room for 2 marking gauges so I need something that I can store separately. Not only does this work great for set up, I can store it offline when using the gauges for other work.

Tim McCollum
Mortise and Tenon Marker

the tool works fantastic and makes the job of marking mortices to match my chisel remarkably easy.