Straightedge tool for corners plan

Here you can download a free woodworking plan which will help you to make a simple tool which we called straightedge tool for corners tool. This tool belongs to ‘marking tools’, it is very simple and will come in handy for any woodworker/carpenter. We got the idea to draw this plan after we saw the simple tool at an old carpenter’s. We were interested in what it was for, and were told that its purpose was laying out lines that must meet at a corner. The tool looks like a hinge i.e., it consists of two leaves with knuckles and a pin. A pin is inserted through the knuckles and works as an axis of rotation.

Straightedge for corners plan


We started a conversation with the old carpenter, and he told us that in his work he had used this tool a lot to mark woodworking joints (Bridle, lap and mortise and tenon woodworking joints mostly). We also learned from him that, in general, the tool was not used as frequently as before because there was less need for marking woodworking joints. He added that he was still happy to use it, as it accelerated laying out lines in some cases. We were delighted with the simplicity of this marking tool, so we decided to offer you a plan on our site on how to make your own piece.

Straightedge for corners - Drawing (Metric units)

Straightedge for corners - Drawing (Imperial units)


The Straightedge tool for corners tool is not difficult to make, and the only thing you need to watch out for is precision, i.e., the two lines you mark with this tool must be normal to the edge and meet at the same point on the edge of the stock. We recommend that you make this tool from quality hardwood or metal. This way, you will be able to use your Straightedge for corners tool for decades, and it will most probably be used by your successors as well. The old carpenter we had met told us that he had first seen this tool at his colleague’s shop; as for his tool, he said, it was made from oak wood, and it was surely at least 30 years old.


If you make the Straightedge for corners tool according to our plan, you will be able to mark lines 5.5cm in length. If you want to mark longer lines, adjust the dimensions of the leaves to your needs. With the  increase in the dimensions of the leaves, the effort required to make this tool precise is also increased, so make sure you don't overdo it! A hole-drilled leaf serves to hang the tool somewhere when it is not needed.


We hope that we have made you interested in making this simple marking tool, and that it will become very useful in your work!

This free woodworking plan by which you can make Straightedge tool for corners has been created with the free parametric 3D CAD software FreeCAD.

Download the FreeCAD 3D model of this Straightedge tool for corners: Straightedge tool for corners plan - FreeCAD 3D model

Straightedge tool for corners plan in PDF file format: 

Straightedge tool for corners plan - Metric units

Straightedge tool for corners plan - Imperial units