25VIDEO Tour of Squares

In this video, I want to tell you the basics of squares

This is something you need to know early on. I have a bunch of different squares here

They all serve at least one common purpose, and that's as a reference point for 90 degrees

That's what square means in the world of woodworking, and 90 degrees is what you have here

Now, the square you should start with is something like this. This is called a combination square

and it's because it does a bunch of different things. First of all, it does provide the all-important 90-degree reference

And this is what you'd use when you're, say, marking a piece of wood to make a square cut

But this, of course, also does other things, too. The most useful is the fact that you can loosen this lock nut here

and you can slide the top part. Why is that useful? Well, many times you want to mark a certain distance

from the edge of a piece of wood, say. And you could grab a tape measure to do that

but it's easier and more accurate to actually set this for a particular dimension

Let's say 4 inches. 4 inches here, and then we tighten it up

Now, let me grab a piece of wood, and I'm going to show you how I would typically use the

I will call it the depth-setting feature of a combination square. So, I've got a scrap piece of wood here

adjusted to 4 inches of stick-out. I can put this on the side and slide it

and I can also slide it with a pencil in place. So, if I want to mark a certain distance from the edge

or the end of a piece of wood, it's quite useful for that

Less useful, but handy to have, nevertheless, is this side here, because whereas this gives us our 90

well, this gives us our 45, which is half of 90, and sometimes you do need to mark things off at 45 degrees

One other use is this little level bubble here. If you're doing any sort of building or construction

you want to use a proper carpenter's level, but sometimes a little level like this is handy

and all the combination squares that I know of have those. So, fairly inexpensive

Don't buy the cheapest one you can find. I mean, this Irwin one is quite good

S-T-A-R-E-T-T is another brand name, but around for a long time. They make all kinds of measuring and marking tools

I own a couple of Starrett's, too. They're very good. They last a long time, and they're very accurate

So, that's all you need at this stage as a beginner when it comes to squares

but I do want to tell you about a few others so that you know they exist

and maybe they'll make sense for you in the future. When I'm in the shop

so not when I'm building a building somewhere or framing a roof or something like that

but I'm working on furniture or some sort of fine woodwork in the shop

I use this square a fair amount. This is a machinist's square, so it's not actually made for woodworkers

but the claim to fame is that it's highly accurate. And when I say highly accurate, I mean this is supposed to be 90 degrees, right

Well, this is accurate to 90 degrees up to a tolerance of 1,000th of an inch

of deviation over the length of the blade, so it's extremely accurate

These other squares are fine. I would consider them to be accurate enough for most applications

but you do need extreme accuracy sometimes when you're setting up machines

for instance, and I'll touch on a little bit of that later. But for instance, the blade coming out of a table saw

it's a circular blade that comes out of the top of a table saw

Very often you want that blade to be perfectly square to the bed of the saw

Well, this is the tool for that. Same goes for the jointer and some other stationary woodworking machines

So machinist's square. It's nice and handy, too. It's small, so you can pop it in your pouch if you use that in your shop

It's also extremely useful for checking the accuracy of cuts you've made

either by hand or by machine, because, I mean, this is a pretty big piece of wood here

but all I really care about, for instance, in this square cut here

is this cut square here in the short term. It is at this end, and it isn't quite

It deviated a little bit here. But I'll also use this square, because it's so handy

It's in the pouch all the time. I want to see, oh, have I set that machine up correctly

Let me see how square it's cutting. Yeah, it's doing very well

Actually, this is kind of interesting. It's kind of interesting. This is a factory edge

It's supposed to be 90 degrees, but, wow, look at how far off that is

Sometimes factory edges and ends are nice and square and reliable. And other times they're not

I can't remember actually ever seeing one this far out of square before

when it comes from the factory. Anyway, on to a few other squares here

This is one I use all the time, but not generally for fine woodworking in a shop

This is a carpenter's square. This is what you'd use to build a building

There's a bunch of numbers on here, and not just the length numbers

but there's smaller numbers here, and those can be used to help you lay out a roof, rafters, things like that

You don't need to worry about that right now, but this would be one that I use fairly commonly

although not usually in the shop. I do sometimes use it in the shop if I have a big piece of wood

and I want to mark it square or something like that, maybe for rough cutting or something

This is a similar square. I got this from Lee Valley Tools

It's a Japanese square, they call it, and it's small and light and accurate

I don't often use this one over this one, but there is something a little tricky about it

Which one is it here? Yeah. This is an imperial measure here, so it's inches

It's from the imperial system, and this is kind of what you're used to seeing

But different parts of this are graduated in tenths of an inch

not sixteenths of an inch or thirty-seconds of an inch. It's kind of weird

It's kind of a decimalizing the imperial system, which is not typical for these sorts of things

and it can throw you off if you don't know that. You're thinking you're marking two and one-sixteenths of an inch

and it's actually 2.2 inches. Anyway, it's not a problem you're going to run into very often

but I just thought I'd mention that briefly. There is the whole world of digital squares and marking tools

Now, this isn't actually a square. This is called a sliding tea bevel

and it happens to be digital, so I want to show you that as well

You can turn it on and loosen it off, and look at this

It changes. So you can get your 90-degree corner, but this is more for measuring a particular situation

So, you know, what is the angle of that, say? And you can turn it and lock it

and now you know what degree you need to cut a piece of wood to

So this is kind of a fancier 21st century version of the standard sliding tea bevel

This was actually a tool that my great-grandfather, Robert Maxwell, the cabinetmaker, used in his work

I still use it a lot, too. It doesn't have the numbers on it

but you can use it to measure an existing angle and to lock it, and then to simply take that angle

and transfer it this way. So you don't really know the number

You never really know the angle you're working at, but it doesn't really matter

because this matches the angle that you're matching to. So that's essentially the world of squares

and, you know, just to recap, buy yourself one of these. Buy a good one

Buy a brand-name one. Keep it lightly oiled. It'll last forever. Once you get into machines, if you do

then this is the square to get, and if you want to build a garden shed or some kind of a larger structure

then a carpenter's square is your thing