When you drop the Center Gauge on the edge of your stock and squeeze the two sides together, the marking bar is perfectly centered on your stock. It can’t help it. It’s the simple geometry of a parallelogram. With a hole milled precisely in the center of each bar, all you have to do to mark the center of any piece of stock is place a pencil in the hole and slide.  And, to lay out a mortise or tenon centered on your stock, just mark both sides of the bar. 

It's that simple. Each of the stainless-steel interchangeable marking bars has a specific width. You can get the Center Gauge with 1/4", 3/8", 7/16" and 1/2" marking bars or with 4mm, 5mm, 6mm, 8mm and 10mm, or the complete set with all 9.

Keep yourself CENTERED
The Center Gauge eliminates the guesswork from precisely centering mortise and tenon joints. The precision-machined parallel arms quickly adjust to the stock thickness, placing the marking bar right in the middle. Just scribe each side of the bar and you’re done. 

Each marking strip is precision machined from high-grade metal (ideal for working with marking knives), and each has a pencil guide at its exact center. The parallel arms open to accommodate stock up to 2" thick.

Choose from four mortise and tenon widths (five for the metric system). Changing the width of your mortise and tenon layout couldn’t be easier. Simply remove the two thumb screws holding the marking bar in place and switch to the width you want. 

The imperial set comes with 1/4", 3/8", 7/16", and 1/2" marking bars. For the metric version, you'll get 4mm, 5mm, 6mm, 8mm, and 10mm widths. Or, if you’re like most woodworkers these days and work in both inch and metric depending on the project, the Deluxe Kit includes all nine marking bars. These are all the sizes you need for stock from 1/2" to a full 1-1/2" thick and more. 

The Center Gauge has been a popular OneTIME Tool over its handful of releases. Now, we decided to make it part of our permanent lineup.