New square required!

[Jacob]

The problem with engineers squares is once they get up to around about 12'' or 300mm the stock is becoming a bit too heavy to be comfortably used in the way most woodworkers use them, i.e. with one hand holding the blade flat on the workpiece while the other hand scribes or pencils a line. At this size and above the weight of the solid steel stock trying to swing down risks introducing inaccuracies.

You get a similar problem with wooden handled ones. If the blade isn't broad enough to contain the centre of gravity, the square won't sit on the workpiece without tilting. Doesn't introduce error it's easy enough to hold in the right place, but it can be inconvenient if you are doing a lot of marking up - not being able to leave it sitting in place whilst you sharpen a pencil or blow your nose etc.

 

[D_W]

About 10 years ago, I acquired a starrett 24" try square for $17 (that's not a typo). It was decommissioned navy goods, and a professor in California had made a hobby of acquiring decommissioned goods and storing them....until he died (I'll never understand that...if you're just going to acquire a pile and then die, what's the point?). Anyway, a relative was selling his stuff off on ebay....

...fast forward to now, the comment about weight rings true. You get a free beer in my house if you can accurately mark a tenon one-handed with the 24" try square without dropping it or getting cut by it.

The japanese have accurate flexible light weight squares for this kind of thing, and to my knowledge, mark with ink - not like a pen, but with ink on a striking tool that releases it easily. I've used my starrett square to set steel carpenter's squares for large cabinet marking, but find them awkward to use for accurate work. The japanese marking tools are flexible so that you can bend them against a reference surface and get good positive contact (which can be hard to do with a rigid carpenter's square).

At the same time, I've developed an aversion for aluminum marking tools over the years. There's a serious durability issue there, and some of the branded "guaranteed" aluminum squares sold in the US are not actually square (but they're as expensive as they would be if they were!).

I suppose there are a lot of subtleties (perhaps that's true of a lot of woodworking topics), one of which is that in my suggestion above about hardened heads on combination squares, you have to be able to spot heads (and rules) that aren't defective or worn (which seems like common sense, but it's not going to be that common if someone doesn't have the experience to have the sense), which you can clearly verify in the pictures of the expired auction. Or beyond that, if you're buying from an antique tool dealer with less than honest intentions, rules and heads can be put together without any regard to whether or not they actually lock up square, or at all. My first starrett combo came from a well-respected tool dealer here in the states, and the head and rule cannot lock up at all - there is always play. It's obvious that they were assembled by the dealer and not originally together, because it isn't just a wear issue.

 

[Bm101]

(Just a beginners thoughts)
I've been holding back because the big boys are involved but no one has mentioned Kinex squares so far so I thought I'd mention them. Engineers squares so not for everyone but a deal cheaper than starret. I have the 150x100 and 75x50 fropm Workshop Heaven though they may be available elsewhere etc etc etc ad infinitum. The liitlun I find useful for all sorts. 'Bang on' square is more than good enough for me. I've visited an engineers workshop and seen what true accuracy entails. I'd be lucky and brave to even try and replicate that with my half a*sed attempts but I love and cherish those little squares because they give me confidence even though I will never need DIN 875/0 in real life. They give me confidence and I take real care of them .
I have a Moore and Write combination square that seems true off the big kinex and a stanley combinaion that is relegated to diy. :|

https://www.workshopheaven.com/hand-too ... nders.html

 

[MusicMan]

To my mind the ideal square is adjustable, and has a push-out slip, the same thickness as the blade, near the end of the stock. This slip avoids the problem mentioned by Custard, of a heavier square rocking. The figure shows a Bridge City square to this design. I bought a set of three of these when I worked in the USA (when they were cheaper and I had more money!) and use them all the time. This model is not relevant now, as it has been discontinued (and BC prices are now ludicrous though they are beautiful tools!), but maybe someone knows an equivalent, or will be inspired to make their own to this design?

Note the support slip in the bottom left of this square.

The slip of wood at the top of the square is a shallow wedge, to ensure that the weight of the blade does not rock the square while setting.

For setting, one can use the straight edge and flip square method, but I never find this very good. First one has to make sure the edge is really straight. Then you can only use it a few times before there are so many lines that they are indistinguishable. I use a four-sided jig that magnifies the error by four, and is self-calibrating (as four right angles is a complete circle). I estimate the accuracy is about 0.003 degrees (10 seconds of arc).

The pictures show two of the squares with my high accuracy square setting jig, which I trot out whenever the subject of squares comes up: high-accuracy-square-setting-jig-t93871.html. Apologies to those who are bored by seeing this!

I made this out of wood because I wanted to practice making the sides square and straight, and had some 150 year old teak to use. It would be quicker, probably more accurate, and more sensible to use aluminium extrusion, e.g. T-track or 2030 extrusion (checked for straightness by ensuring that any three of the side pieces will match with no gaps).

The jig lives on the workshop wall and can be used to check a square in a few seconds. I do this whenever starting a new project. It will handle combination squares. There are obvious modifications one can make to handle T-squares or inside squares.

The same principle can be used for 45 degree angles, but needs eight sides and gets a bit fussy!

Keith

 

[Jacob]

I just bought a cheapo at £3.98 mainly in the hopes that the scribing pin would replace the missing pin from a Bahco square.
It fits!
Checked for accuracy - it's spot-on in woodworking terms; random variations no more than thickness of a 2H pencil line.
The scale is excellent but the stock is lightweight compared to the Bahco which is also alloy but much heavier.
But perfectly usable and has the two contact points which could be filed for adjustment.
5 stars for price, 4 stars for quality!

 

[nabs]

I dug out my old Bahco square and the mechanism to keep the ruler square to the stock is indeed as bugbear described in an earlier post (the hook engages with the slot on the ruler and pulls it down on to two small rails), so I obviously misremembered how I adjusted it.

I also worked out why it was now out of square - the ruler does not lie flat anymore - it curls up and I think is slightly twisted. This is not a manufacturing fault though, as it has a hard life being used outside on building projects (I probably trod on it several times!)

Abuse aside, given it is simple to get a combination square square - assuming the ruler is machined straight/parallel, which it is (was) with my Bahco - by adjusting the rails with a file or bit of sandpaper, then I suppose it is reasonable to ask why it is worth spending more.

D_W makes a good point about the better quality ones being hardened - on close inspection there are lots of nicks and dents on the edges of my Bahco rule but my hardened Starrett, which is nearly 40 years old, is perfect. Is there some other reason?

PS I assumed that all the Starretts were hardened - interesting to hear that this is not the case.

small steel rail just visible:

bahco and Starrett - not a lot to either of them, really!

 

[D_W]

Hardened steel, cast, etc, simply wears much longer and dents much less easily. If something dents less easily, as long as a corner, etc, doesn't break, it means the wear surfaces will deform less easily.

Slower wear and less deformation means:
* smoother action
* longer lasting
* closer to initial squareness

I guess this is one of those tips that works a fair percentage of the time, but each time I mention it, there is some dissension about why it's not a good tip. Is it too subtle? i don't know. You've found the same thing I have, though - that of the squares you have, the hardened one is just in better shape.

 

[AndyT]

I'm quite surprised that having only just managed 8 pages on squares we've found another four pages worth already.
Inspired by it all I've just spent a few minutes comparing the various old and new squares in my workshop.
The good news is that they are all square enough except for one poor specimen I suspect was made in a school metalwork lesson. I only keep it on the superstitious grounds that it came with the right initials stamped on it.

However, I have noticed one other factor that differentiates some of the squares.
One that I find really useful is a little nameless engineer's square that I bought from Axminster. It's very handy for marking round small stock or squaring down dovetails. Its blade is 3/4" x 1/16" and its stock is 3/4" x 3/8". I generally work in inches as most of my tools are old and I find this feature really useful. It would be nice for metric workers if there was an equivalent in metric round numbers, say 1, 10 and 20mm.

I happen to have two "precision ground" squares. The older one, by Moore and Wright doesn't refer to any external standard but the other, by now-defunct maker Fisher of Canterbury is marked as BS939 grade B.

On both of these, the stock is annoyingly short of any useful size, at about 31/32" by 11/32". Presumably this is the effect of grinding a stock piece of steel down until it achieves squareness.

So sometimes, they are less useful than the non-certified cheaper version.

 

[Peter Sefton]

Andy, Fisher are still made, these are the squares I use and supply to BS939.

My small 2" one sounds the same size as yours with a 3/4 x 1/16th blade as you say great for dovetail work. Fisher also make combinations squares but are not worth buying in my opinion.

Cheers Peter

 

[AndyT]

Oops, thanks Peter. I thought I had looked them up when I got the square but maybe the info on my old packaging is out of date.

 

[whiskywill]

Edit- just to add the adjustment screws stick out, unlike the stock photo.

They don't on mine. They are recessed.

 

[ColeyS1]

Edit- just to add the adjustment screws stick out, unlike the stock photo.

They don't on mine. They are recessed.

You must have had a good one

Did yours have loads of filler around the brass bits ?

Sent from my SM-G900F using Tapatalk

 

[Glynne]

Andy, Fisher are still made, these are the squares I use and supply to BS939.

In light of this thread I checked all of mine yesterday, and the Fisher I bought from Peter some time ago is my reference.
I checked this and then all of the others against it and surprisingly only one was slightly out - amazing given how clumsy I can be.

 

[patrickjchase]

If you really want accuracy then combination squares are right out, as that sliding interface inevitably wears and compromises accuracy. Hardened heads help, but only to a point.

No, a Real Woodworker (tm) must have a few fixed master squares like the Starrett 55- and 20- series in various sizes. The Starrett 20-24 is a particularly attractive bargain in a 24" square for the low low price of $1800 or so.

FWIW and IMO, chasing precision for woodworking is a fool's errand. British class B (1 mil per inch of squareness tolerance) or the corresponding modern tolerance is adequate for most work, particularly once we learn to avoid unfortunately tolerancing stackups in our layouts.

Disclosure: I have a Starrett 55-6, that I mostly use to check other tools and rarely for metalworking. I also have a bunch of other squares of varying accuracies. Probably the biggest surprise of the lot in terms of "accuracy per dollar" was the Vesper double square, which comes close to rivaling the Starrett *fixed* squares' accuracy at lower price.

 

[Cheshirechappie]

If you really want accuracy then combination squares are right out, as that sliding interface inevitably wears and compromises accuracy. Hardened heads help, but only to a point.

No, a Real Woodworker (tm) must have a few fixed master squares like the Starrett 55- and 20- series in various sizes. The Starrett 20-24 is a particularly attractive bargain in a 24" square for the low low price of $1800 or so.

FWIW and IMO, chasing precision for woodworking is a fool's errand. British class B (1 mil per inch of squareness tolerance) or the corresponding modern tolerance is adequate for most work, particularly once we learn to avoid unfortunately tolerancing stackups in our layouts.

Disclosure: I have a Starrett 55-6, that I mostly use to check other tools and rarely for metalworking. I also have a bunch of other squares of varying accuracies. Probably the biggest surprise of the lot in terms of "accuracy per dollar" was the Vesper double square, which comes close to rivaling the Starrett *fixed* squares' accuracy at lower price.

Hello, and welcome to the forum!

One small point - the use of the word 'mils' confused me slightly. I read it as 'millimeters' to start with, but as that made no sense in this context, I googled it. Seems it's a commonly used US shorthand for 'thousandth of an inch' - which made much more sense. The term 'mils' isn't used in the UK (we call 'em 'thous'), where we have dual use of Imperial and Metric systems, with Metric (usually SI) predominant in engineering. Thus, 'mils' would be read as 'millimeters' or possibly 'millionths of an inch' in the UK. Not really a woodworking matter, but as it cropped up I just thought I'd mention it in case confusion arises!

 

[JohnPW]

In the UK, "mil" is short for "millimetre".

 

[custard]

If you really want accuracy then combination squares are right out, as that sliding interface inevitably wears and compromises accuracy. Hardened heads help, but only to a point.

No, a Real Woodworker (tm) must have a few fixed master squares

#-o

Oh dear. I've principally used combi squares for several decades. Guess that's me ruled out as a "real woodworker".

Welcome to the forum Patrick, looking forward to seeing your work.

 

[Tasky]

In the UK, "mil" is short for "millimetre".

In the context of speech, sure... But in written communication, that's what 'mm' is for.
But when I read, it my mind automatically thinks of 'mils' as in milliradians, where you have (by NATO standard) 6400 mils in a 360º circle.

 

[John15]

An accurate square should allow you to mark a shoulder line that lines up on all four sides of your square workpiece. If it doesn't it's not a lot of good.

John

 

[transatlantic]

An accurate square should allow you to mark a shoulder line that lines up on all four sides of your square workpiece. If it doesn't it's not a lot of good.

John

Not the best test in the world. Your workpiece is far more likely to be out of square