It’s hip to be square: combination or double

[Tony Wilkins]

I want to get another square a bit smaller than my 12” combination square. I’m thinking a 6” (maybe 4”) model. I’m leaning towards another combination square but then there’s the very similar double square. Is there any advantage to the double square? I’m not sure why one would get one rather than the combo but I’m also aware I might be missing something.

[Jim Koepke]

For some reason combination squares aren't my first choice.

Fixed try squares are more to my liking.

My 12" combination square is used mostly for marking off a 45º cut. There are a few different sizes of them in my shop. For an adjustable square a double square would likely be my choice. It could be like having two different size squares on the same stock.

jtk

[Tim Null]

I use a 4" double square more than my combo square. It is great for all types of measuring and marking. If I had to choose one, it would be this one.

[Bob Leistner]

The trouble with double squares is you have to remember which side you are using. If you set the ruler at a specific length, the other side is close to the same and can catch you if you are not very careful. I hope this makes sense. Won't happen with a combination square.

[James Pallas]

Both. Different tools for tasks. Small combo for the miters on smaller work. Double for things like marking tenon length with one side with a tick mark than using the long side to square across. I like the 6" for that reason. 4" is not quite long enough to mark both on a 2" piece of work. Squares are a bit like marking gauges. No mater how many you have you always need just one more for the task at hand.
Jim

[Andrew Seemann]

I use 12" combo squares, a 6" combo square and old Stanley 6" try squares. I use the 6" try square the most, for squaring and measuring. I don't have a double square. The 6" combo square seems like it would do everything the double square could.

[Bill McDermott]

12" fixed, 12" combo, 6" fixed and 4" double -- all front and center and used all the time. They all seem to be obvious choices for various tasks at the time I am grabbing for one. They really don't seem to overlap that much. Of course, if I had a different selection, things would play out differently. I don't have (or want) a 6" combo.

Upshot: 4" double is a very nice compliment to a 12" combo (for me). 12" is for careful layout and final checking. 4" double is for the back and forth work like jointing an edge or chopping to depth. It's small, light, quick to hand and quick to the work.

[Rob Luter]

I have a number of squares. My empire 6" combo gets a fair amount of use. It has an aluminum body and a SS blade. It's as accurate over the 6" as my 12" Starrett is.

[Mike Henderson]

I have a wide variety of squares including the giant Starrett 8HC (http://www.starrett.com/metrology/product-detail/8HC), standard 12" combination squares, smaller 6" combination squares, and a bunch of 4" double squares. I probably use the double squares the most but that's just because of the work I do. The 6" combination square gets used mostly for 45 degree things on smaller work. The 12" for putting a square line across boards, and the 8HC for squaring large work.

You won't regret getting a 4" double square. The best quality for the price is a PEC blem on eBay. They are accurate and have a good feel. Also American made. If not that, the iGaging double square is very good but is not as smooth as the PEC.

Mike

[Dennis Tebo]

Mike,

I hope you keep that giant Starrett locked up in a safe when not in use!

Dennis

[Hasin Haroon]

I second the 6" or 4" double square recommendations - smaller squares are tougher to use to mark 45 degrees than the 12" combo squares.

[Bill Houghton]

The trouble with double squares is you have to remember which side you are using. If you set the ruler at a specific length, the other side is close to the same and can catch you if you are not very careful. I hope this makes sense. Won't happen with a combination square.
On the other hand, if you're doing something where you're using the square to mark a specific short length (say, 1/8" from an edge) and you also need to strike a line across the stock, a double square can let you do both things (sometimes) with one tool.

The stock (handle part) of a double square is usually longer than that of a combination square, giving you more registration on the edge. I worked for years with combination squares until I scored my first (6") double square at a yard sale and became something of a convert. Now I wish I could find a 12" double square for times when my 6" and 4" squares are too small.

[Tony Zaffuto]

I have a very large number of squares, but my most used are 6", 9" try squares and a 2" macinist square.

[glenn bradley]

A 4" and 6" double square do the lion's share of the work in my shop.

[Mike Henderson]

Mike,

I hope you keep that giant Starrett locked up in a safe when not in use!

Dennis

Yeah, it's kind of expensive. But I bought it used on eBay and got it for a decent price. I don't remember exactly what I paid but I'm pretty sure it was under $200. A lot of people don't follow listing for the 8HC so sometimes they go fairly cheap. And sometimes a seller who buys estates doesn't realize what the square is and lists it as a Buy It Now for $100 or so. If you really want one and are willing to wait, you can find them for a reasonable price.

I really like mine for certain situations.

Mike

P.S. to see how big that 8HC is, here's a picture of it compared to a standard 12" Starrett combination square. The blade on my 8HC is has some marks and wear but the head is in good condition.
403651

[Tony Wilkins]

I decided on Sterling 4” double square with the dovetail rule. I’ll see how I like that and then probably get a 6” once I decide.

[Frederick Skelly]

I had a set of machinist squares and a 12" Starrett Combo. A thread here convinced me to try a small double square. Fell in love - very handy and usually my go to square. Now I have 3 of them, in 4" and 6". I prefer the PEC over the iGaging because of the smoother feel while sliding the blade. Otherwise there's no discernable difference.

[Frederick Skelly]

I decided on Sterling 4” double square with the dovetail rule. I’ll see how I like that and then probably get a 6” once I decide.

Bet you'll love it. That's a nice tool.

[Orlando Gonzalez]

I'm sort of in Mike Henderson's ballpark. I have Starrett 3" and 6" Double Square. Starrett 6", 12" and the 24" Combo Squares. Starrett 1-1/2", 4-1/2", 6", and 12" machinist squares and a Mitutoyo 6" machinist square and a (c. 1872) Darling, Brown & Sharpe 4-1/2" machinist square. They all get used when appropriate. I think I have a sickness for these things.

[Tony Wilkins]

I also want to make some wooden try squares in future. I’m planning on trying the one CS does based on the squares Seaton Chest.