Woodworker's Journal 2008-32-5, страница 66

Today's SHOP

Combination squares break down into three general categories.

Because the groove is centered, you can switch the orientation of the graduations by pulling the blade out of the head, turning it end-for-end, and reinserting it. You can also roll the blade over, but to do that, you have to spin the lock bolt 180° to accommodate the repositioning of the groove.

The head has three ground reference faces: one parallel to the blade, a longer one perpendicular to the first (and thus to the blade), and the third at 135° to the first (and thus at 45° to the blade).

Incorporated into the head is a bubble level so you can check for both level and plumb with the tool. A small scratch awl usually is held in a bore atop the head; this works better for marking metal than wood.

This is the combination square a carpenter uses. Every trades-person has one, too. And DIYers gravitate to such squares, as do many woodworkers.

A machinist is likely to have a more sophisticated version of this square, made with different materials, different finishes and different graduations. He'll have two additional heads: a center head and a protractor head. A square purchased with all three heads is known as a four-piece set.

Variations include models with longer blades and downsized models with 4", 6", or 7" blades.

Three Categories

Combination squares, it seems to me, sort themselves into three

categories. Superficially, the sort is based on price — low, medium and high. But the prices reflect the materials used, the design specifications and features, as well as the manufacturing procedures. Manufacturers generally focus on a single category, rather than producing squares at each level.

Rather than go out to collect and evaluate tools from every single manufacturer, I sampled. I got combination squares from Stanley and Craftsman, two well-known inexpensive brands, and from L. S. Starrett and Brown & Sharpe, two highly regarded premium brands. I also got medium-priced squares from Gladstone, Rockier and Highland Woodworking.

In the low-end category are the two-piece squares sold at hardware stores, home centers and lumberyards. Brands include Stanley, Craftsman, Empire Level, Johnson Level and Swanson. On average, they sell for $10 to $20.

Today's Shop continues on page 68 ...

Good

Combo Squares:

Stock Preparation

Why are combination squares irreplaceable? Well, come on, I double-dog dare you to try to complete a woodworking project without on'e. I find it nearly impossible to even begin work in the shop without putting my hands on one of my combination squares. From preparing stock to initial layout, all the way to squaring up subassemblies to mounting a project on a wall — combination squares are off the hook and in my hand. Here, and in the pages following, are some of the tasks I require this shop stalwart to perform ... I know there are more!

— Bill Hylton

66

Don't try woodworking without one!

Critical to success in any woodworking project is to have stock that's straight, flat and true. How do you know if your stock meets the requirements? You use a combination square. Is your edge square to the face? Is your miter a perfect 45° cut? Is your chop saw creating a dead square end when you cut off? Your combination square is the test against which your machining is measured.

October 2008 Woodworker's Journal