Lee Valley Small Double Square

Tool: Small Double Square Shop Now 

Manufacturer: Lee Valley

MSRP: $49.50

A diemakers’ square with a narrow blade is an excellent tool for determining minute problems with your joinery, allowing you to get in between narrow dovetail pins, for example, to check for sloping walls. But a true diemakers’ square (on which the blade angle can be adjusted for patternmaking) is quite expensive, even on the secondary market (though Lie-Nielsen sells a well-priced version if you don’t need a narrow blade).

Enter the “double square” – a similar tool, minus angle adjustment.

Lee Valley has a small double square ($49.50) that comes standard with two 2 1⁄2“-long blades; one is 1⁄2” wide, the other just more than 3⁄16” wide, with a 3⁄32“-wide, 1⁄2“-long probe on one end for sneaking into the smallest of places.

The stock is dead-square to the blades, and the rules are easy to change – though the center pin (the rule catch) does rotate in the body. (It does not on the $140 double square from Vesper Tools, which comes standard with three blades and also includes a 45° reference bevel on the stock, where the Lee Valley one does not.)

Out of the box, the edges of the square I used were very sharp, so I took a few minutes to burnish them. 

I sure wish that probe were longer – the 1⁄2” length limits its use to thin stock. But if you don’t cut quite narrowly spaced dovetails, it’s a non-issue.

All in all, this small double square is a good tool for the price.

Oh – and about that box it comes out of? This is a precision tool that should be stored with care, not just tossed in a tool tray; the French-fit box makes that a no-brainer.