Decent try square

[MarkDennehy]

Is that really going to be any better than the draw a line (with a mechanical pencil or even better a knife) and flip over test? I don't think so.

Thing to remember is that that test is entirely dependent on the flat edge you reference against being actually flat.
And you made that edge with a plane.
So the tolerance in the square can't ever exceed the tolerance to which you work with the plane; and since that's probably your most accurate tool, that's grand for practical purposes.

You get a certified square, they'll have dialled that in with a dial indicator to waaaay beyond the accuracy of your plane so the answer will be better, but you won't be able to work to that accuracy anyway so it's an academic benefit at most really.

It's when you cannot measure as or more accurately than you work that the problems arise...

 

[Andy Kev.]

Having read the contributions on here I decided to have a look for certified squares. Moore & Wright do one but the price!!! 157.95 quid!!

Is that typical or is that a really super-dooper, extra special, certified square?

 

[bugbear]

Having read the contributions on here I decided to have a look for certified squares. Moore & Wright do one but the price!!! 157.95 quid!!

Is that typical or is that a really super-dooper, extra special, certified square?

What accuracy is it certified to?

BugBear

 

[Phil Pascoe]

I paid £2 for a Draper at a car boot - it's the only square I've seen with a B.S. No. on it.

 

[Stevedimebag]

Sorry to take the post back to the original subject but...
I got the starrett today...£5.57 or something like that on amazon.
I tested it against a few kitchen doors to test for accuracy - was about half a mil out over 250mm length. Contacted amazon for a refund...filled out the form bit and it just said to not bother returning it and I will get a refund anyway...
Just tested it again and realised the kitchen doors weren't perfect andso they had kicked it out. Tried it on some truer kitchen cabinet faces and it looks half decent. Certainly fine for my needs right now.

Moral of the story? Ask a simple question about a hand tool and expect a lesson on theoretical quantum physics...unexpected but nevertheless interesting

 

[Andy Kev.]

Having read the contributions on here I decided to have a look for certified squares. Moore & Wright do one but the price!!! 157.95 quid!!

Is that typical or is that a really super-dooper, extra special, certified square?

What accuracy is it certified to?

BugBear

It said UKAS calibration to DIN875 and that the certification process takes about seven days. I tried to link to it but it wouldn't work.

 

[Seiken]

I've got some engineers squares from toolstation
https://www.toolstation.com/shop/p23063?table=no
They claim manufacture to DIN875/1 and even if its the lowest grade in the standard I cannot see any indication of out of square when checking by drawing a line when butted up against a table edge and flipping the square over, and they are less than a tenner.

 

[D_W]

Having read the contributions on here I decided to have a look for certified squares. Moore & Wright do one but the price!!! 157.95 quid!!

Is that typical or is that a really super-dooper, extra special, certified square?

it's a bit cheaper than Starrett's efforts, but probably also less accurate.

None of it has anything to do with woodworking, though, which is why you'd like a machinist to have the certified square for use for you. They may actually use it for something, so let them pay for it. Give them a beer or something, I don't know.

 

[D_W]

http://www.starrett.com/metrology/produ ... -6%20W~SLC

One ten thousandth of an inch over 6 inches, and hardened. I'm sure you could find one cut rate somewhere, but who knows what the discount price is. Some amount that you'd like someone else to cover is what I'd say.

 

[bugbear]

Having read the contributions on here I decided to have a look for certified squares. Moore & Wright do one but the price!!! 157.95 quid!!

Is that typical or is that a really super-dooper, extra special, certified square?

it's a bit cheaper than Starrett's efforts, but probably also less accurate.

It will be as accurate as it's certified to be, and so will Starrett's "efforts", no more, no less. No engineer worthy of the name would assume that an item of metrology was more accurate than its certification because of the brand name.

BugBear

 

[D_W]

Having read the contributions on here I decided to have a look for certified squares. Moore & Wright do one but the price!!! 157.95 quid!!

Is that typical or is that a really super-dooper, extra special, certified square?

it's a bit cheaper than Starrett's efforts, but probably also less accurate.

It will be as accurate as it's certified to be, and so will Starrett's "efforts", no more, no less. No engineer worthy of the name would assume that an item of metrology was more accurate than its certification because of the brand name.

BugBear

Starrett has three grades, or perhaps two. One is toolroom, another master square, and this one is master with certificate. It's not a matter of meeting the certification here, it's a matter that Starrett's square is certified to be .0001 over 6 inches, and I see 875/DIN somewhere as .0007 over perhaps 8? It's a looser standard.

If M&W manufactures one to that standard, it will be the same. The cost likely will be, too.

Standards not withstanding, the English friend of mine considers Starrett to be more reputable.

You can certify or guarantee whatever, but there will still be variance from business to business in meeting or exceeding standards.

Incra, for example, couldn't manage to make a certified or guaranteed square, well, square. It probably even had a certificate with it.

 

[D_W]

Starrett's low-cost square is specified as .0002" over 6 inches, but not hardened. It's cheaper than the M&W, but it's stainless and not hardened.

I'd choose the M&W at that price, from experience, as things not hardened but supposedly extremely accurate....well, they don't hold up to their spec too long unless extreme care is taken of them.

In reality, though - my English friend's got a certified square, and I just use his to check any junk I pick up. I'd never buy either square (not one for $147, and not for 157 pounds).

 

[G S Haydon]

Sorry to take the post back to the original subject but...
I got the starrett today...£5.57 or something like that on amazon.
I tested it against a few kitchen doors to test for accuracy - was about half a mil out over 250mm length. Contacted amazon for a refund...filled out the form bit and it just said to not bother returning it and I will get a refund anyway...
Just tested it again and realised the kitchen doors weren't perfect andso they had kicked it out. Tried it on some truer kitchen cabinet faces and it looks half decent. Certainly fine for my needs right now.

Moral of the story? Ask a simple question about a hand tool and expect a lesson on theoretical quantum physics...unexpected but nevertheless interesting

Glad you're sending it back. Not sure that a genuine Starrett can be had for the £6.00 mark. I have a 300mm Bacho combination square and it's great. Also got a Faithfull try square that is "square". Also some home made beech squares, also "square"

 

[MarkDennehy]

Christopher Schwarz must be reading the forum again
https://www.popularwoodworking.com/wood ... ers-square

 

[Andy Kev.]

Having read the contributions on here I decided to have a look for certified squares. Moore & Wright do one but the price!!! 157.95 quid!!

Is that typical or is that a really super-dooper, extra special, certified square?

it's a bit cheaper than Starrett's efforts, but probably also less accurate.

None of it has anything to do with woodworking, though, which is why you'd like a machinist to have the certified square for use for you. They may actually use it for something, so let them pay for it. Give them a beer or something, I don't know.

I'm sure that most people would agree with you about the relevance for woodworking. I could just about imagine that a large professional workshop would want one for use as a standard against which to check all the other squares. The limiting thing of course must be the thickness of the pencil line with which you normally work. If any degree of deviation from square over a distance of, say, twelve inches is within the width of that pencil line then that square must surely by definition be good enough to work with (assuming that the pencil line is suitably narrow). Or am I not being strict enough?

 

[D_W]

Having read the contributions on here I decided to have a look for certified squares. Moore & Wright do one but the price!!! 157.95 quid!!

Is that typical or is that a really super-dooper, extra special, certified square?

it's a bit cheaper than Starrett's efforts, but probably also less accurate.

None of it has anything to do with woodworking, though, which is why you'd like a machinist to have the certified square for use for you. They may actually use it for something, so let them pay for it. Give them a beer or something, I don't know.

I'm sure that most people would agree with you about the relevance for woodworking. I could just about imagine that a large professional workshop would want one for use as a standard against which to check all the other squares. The limiting thing of course must be the thickness of the pencil line with which you normally work. If any degree of deviation from square over a distance of, say, twelve inches is within the width of that pencil line then that square must surely by definition be good enough to work with (assuming that the pencil line is suitably narrow). Or am I not being strict enough?

If I had a shop with precision machinery (i have no idea what even goes on in a commercial shop these days, but I worked in a 500 employee cabinet factory when I was in college) and a workforce to use it, I would want to keep a good one in a maintenance area.

The factory that I worked in would require extensive setup. obviously, in a shop with 500 employees, what goes on bears little resemblance to what we think of as woodworking.

Of course, my trick could still be used. I would love to find a hardened starrett square and check it against my friends' square, but I haven't gone that far. The M&W square that I have is plenty nice enough for me, and the large 24" starrett square (never checked to see if it's hardened) is visibly tight with a 6" master square. Whether it is over 24", I'll never know. It is lovely for jig making, though - heavy enough that it doesn't move.

I don't have any nice machinery, so that sort of cancels me out for buying a master square. Unintentional carelessness is also a problem. It's best if I'm not the guy with the nice stuff.

 

[woodbrains]

Having read the contributions on here I decided to have a look for certified squares. Moore & Wright do one but the price!!! 157.95 quid!!

Is that typical or is that a really super-dooper, extra special, certified square?

it's a bit cheaper than Starrett's efforts, but probably also less accurate.

None of it has anything to do with woodworking, though, which is why you'd like a machinist to have the certified square for use for you. They may actually use it for something, so let them pay for it. Give them a beer or something, I don't know.

I'm sure that most people would agree with you about the relevance for woodworking. I could just about imagine that a large professional workshop would want one for use as a standard against which to check all the other squares. The limiting thing of course must be the thickness of the pencil line with which you normally work. If any degree of deviation from square over a distance of, say, twelve inches is within the width of that pencil line then that square must surely by definition be good enough to work with (assuming that the pencil line is suitably narrow). Or am I not being strict enough?

Hello,

You don't always use the square for marking lines and not always with a pencil. A knife is finer, so less tolerant of out of square. And what about trying for square? More often than not I'm using a square to test face side to face edge squareness, and trying the ends of boards for square, and indeed the fence on the saw that cut them. Accuracy is really important if you don't want to go chasing your tail, trying to find out which component is out of square, when an assembly won't quite go together as expected, and your flipping square is no use, cause it ain't.

Mike.

 

[D_W]

I forgot - I took the suggestion of a not-known-in-england-but-the-queen-has-some-stuff-of-his George Wilson and looked for a decent used hardened head combination square.

We used to have a gaggle of precision manufacturers here in the states. I think I ended up with a lufkin square, hardened with hardened rule. It's dead accurate, it slides easily and it's cheap. It is the only square I really use on a regular basis until the reach goes beyond 8 or 9 inches of necessary measurement.

I also have some of the US made lower-spec squares that we have here in the states, and a couple of vintage starrett unhardened heads. All of them are wonky. Even the US PEC square was out of whack a little bit - a decent square, but just not up to the same standards and not with the same kind of smoothness.

 

[bugbear]

is visibly tight with a 6" master square.

This guy gives a as-cheap-as-it-can-be (*) way of getting a quantitative indication of squareness.
You need a reference square, a surface plate, and a dial indicator.

https://www.youtube.com/watch?v=pY3TNiabb3A

BugBear

* you should see the way he normally does it!!

 

[MikeG.]

Too many moving parts to take that seriously. If the surface of the table is fractionally bowed, for example........