why use a combo square?

[Greg Portland]

I've seen a few recent posts asking for high end combo square and/or tool setup equipment recommendations. For what purpose are people using these squares or the other attachments? For square cuts, I have a crosscut jig & my TS rip fence. Both of these have been "calibrated" by using the 5-cut method. For angled cuts, the scale is too small to perfectly dial in a multiple-sided object (8 pie wedges to form a box top, etc.)... you will want to make test cuts in cheap wood anyway (and then tweak your miter angle appropriately).

For setting up 90&deg equipment, I use a drafting triangle (very accurate, ~$10). If I wanted something to stand by itself (and didn't have 2 magnets) I guess I could get a cheap square and calibrate it to the drafting triangle with a hammer & nail set. For a straightedge, I'll use the factory edge of some good plywood or a level. A screw through a board works very well as a feeler gauge for setting up parallelism (miter slot to blade, rip fence to blade, jointer knives to jointer top, etc.).

Am I missing a more advanced usage of the combo square?

[Kent A Bathurst]

layout work. combines a square with a tape. only time I use one with a power tool is for setting TS blade height.

[Peter Aeschliman]

i use mine every time I'm in the shop for layout work. I sometimes use it as a marking gauge (with a knife or pencil).

The sliding ruler is great for measuring depths and transferring them to other workpieces (i.e., a duplicate piece), etc.

Definitely not a necessary tool and there are others that do what it can do, sometimes more accurately. It's kind of the "utility player" of measuring and layout tools in my shop.

[Tom Rick]

Hate to say it but the stack of Starrett gear I have sitting around mostly sits around looking good on the shelf.

A plastic speed square is my go to tool for most lay out.

That and nice flexible cork backed stainless rule get most of the work done and I am not staring at fine graduations on the Starrett trying to pull out the 8ths and 16ths I mostly lay out in.

Get the speed squares in bright orange and they stand out in the bench clutter...

[Bill Orbine]

Every day, Every job... the most used tool in the shop and on the job (asides from measuring tape).. The Combo Square.

[Salem Ganzhorn]

I use a plastic square when I can lay it flat. But for setting the jointer and bandsaw at 90 degrees I really like having a good accurate tri-square. If there is any tilt to your flat plastic square you get an inaccurate measure.

You can make do with a stick and nail for measuring blade parallelism I did for 2 years). But it won't tell you anything quantitative about if your fence is wavy and it cannot measure runout.

As for the original question the combo square is great for layout.

[Chris Padilla]

I love my (older) Starrett Double-Square...fits nicely in the apron.

[dan sherman]

I Have a cheap box store one, and an old Starrett of my dads, and I very rarely use them.

I use my machines squares a lot more frequently. I'm considering picking up a set of Incra t-rules, and if I do I might get rid of combos' because I will use them even less then.

[Chip Lindley]

I have a good General 12" combination square and a smaller 6" Starrett. I use both for very accurate machinery setup. Often a 90 deg. setting must be interpolated because daylight still shows between the finely ground blade of the square and a *flat* saw blade. But by a bit if trial and error, usable 90 deg. settings can be had with table saw, radial arm saw, chop saw, and shaper; Not only between miter gauge and blade, but also vertically, between table surface and blade.

[Rich Engelhardt]

I've seen a few recent posts asking for high end combo square and/or tool setup equipment recommendations
Life's too short to fret about the actual worth - in long range terms - of a $100.00 "top shelf" tool like a Starrett 12" combo square.

[lowell holmes]

You would be quite challenged to mark out the limits of mortises required in a shaker table or a rocking chair with a drafting triangle. I do use a large 30-60 degree triangle for setting up the miter gage on my table saw though.

I would never part with my Starrett 12" square.

[Fred Perreault]

If one wants to set a dimension with the sliding rule on a combo square and carry that dimension and lay it out on other project parts, the combo square is extremely convenient. If one wants a solid tool that can lay out perfect 90's and 45's, again great. After using a 12" and 6' combo for layout for a while, they seem to be almost a neccesity. Yes, there are other alternatives, even shop made units. And you could also use a chainsaw to process your lumber, as well. Surely some workers don't need a combo square, and a few others may not realize the value of one. I have two 12", and two 6", and two 4" squares. One each of a Starret (left to me by older workers), and the others are far less expensive. They are all accurate and often used, but the Starret, which are much older, have taken the ravages of time far better. I also have several older Starret dividers, in great shape. I find them all invaluable for flat work and turning.

[Mike Cutler]

Greg

Nothing at all wrong with using the 5 side method. But if you do a lot of angles cuts, knowing that you can bring the blade back to square in a few seconds is a big help, especially a jointer fence.
Combo squares are indespensible for layout work, and marking. Drafting triangles are also a valuable asset to a shop. It takes all of them.

A combo square is calibrated with a fine jewlers file. There is a ridge in the handle that the blade slides along. To cal a square this ridge is very carefully filed down.

Should you ever borrow a machinists combo square, make sure you back off the knurled nut all the way and pull the scale away from this ridge. If he catches you sliding that scale across that ridge, you may catch an end mill, or a Jacobs wrench in the side of the head. :eek:

[Kent A Bathurst]

..I would never part with my Starrett 12" square.

Ditto. Or my 4" double square.

[dan sherman]

I belive a draw bar is the tool of choice when it comes to dealing with nit wits. :D:D


Should you ever borrow a machinists combo square, make sure you back off the knurled nut all the way and pull the scale away from this ridge. If he catches you sliding that scale across that ridge, you may catch an end mill, or a Jacobs wrench in the side of the head. :eek:

[Paul Canaris]

I tend to use one of two (12” and 36”) Rathbone-Chesterman rulers made of thin flexible S.S. and graduated in metric one side and standard on the other. I picked these up years ago. Paid a lot for them but they have held up very well for 20 years.

I use different sizes of machinist squares for precision tasks; they are heavy and you have to real careful about not dropping them but they are dead on and will stand on their own well when squaring up the sides of assemblies.

For rough cuts I use whatever cheap items I have lying around (combination, try square (wood, plastic etc.).

I tend to drop things, so I don’t even want to think about buying anything from Bridge City Tools or any of the high end makes no matter how drop dead gorgeous it is. :eek:

[Dave Anderson NH]

I like my precision combo square because it is faster than using the 5 cut method. More importantly, when I want to make something with a marking knife there is a real danger of cutting up a plastic drafting square and rendering it inaccurate by taking off minute bits of the edge. I do use the drafting square for rough layout and drafting because it is very accurate and quite inexpensive.

[Jerome Hanby]

Just a versatile measuring/setup tool. But, so is my Number 1 Odd Job and fits in my pocket better;).

[tyler mckenzie]

i have the 12" starret, and eventually bought the 24 inch ruler to accompany it. my favorite tool.

[Dick Thomas]

Dad was a machinist all his life, and as a preteen he taught me how to use a combination square. In my own shop I had a couple inexpensive models, but now I have dad's Lufkin set: square, extension bars, angle guage, center finder and all.

Use them all constantly & will pass them on to my son!

[Chris Tsutsui]

A combo square saves me time for marking materials with pencil that would otherwise be marked using a tape measure.

It's a real time saving device for marking something the same on multiple pieces. I like that it's also a straight edge or ruler.

As far as tool setup I use a fixed engineers square for checking 90 degrees.

[glenn bradley]

I find I mostly grab my double squares but would buy another 12" combo if it turned up missing.

http://www.finewoodworking.com/ToolGuide/ToolGuidePDF.aspx?id=30229

[Larry Edgerton]

The most used tool in my arsenal.

I will not let a speed square on my jobs site, they are useless. I give employees combination squares as they are more accurate and more versatile for fast layout/depth markings. Great tool.

[Tri Hoang]

If most of your operations involve machinery, you probably won't miss much by not using one. I, OTOH, use hand tools quite a bit and find a combo square indispensable. I have 2 of them: 12" and 24". I use them often in marking.

Another indispensable tool for marking is a good pair of divider. Since I learned to use it for marking, I've found additional uses, especially when it's involve some repetitions.

"Marking is the foundation of hand work. It takes as much time and it is as important as cutting the joinery" - according to Frank Klausz and I agree 100%.

[Alex Leslie]

I have a Bridge City Tool CS-6 that is a precision sliding square with a saddle square on it, also. It is my go-to layout tool. The saddle square allows me to draw precision lines and transfer layout marks around corners. The sliding square is great for all the above mentions and positioning mouldings on cabints before pinning. It was rather pricy, but when I consider cost/hr of use compared to the cheaper ones, it is quite reasonable.

[Tom Rick]

Mastery lies in the hand and the heart of the worker.
I wouldn't get too caught up in the need for precision combination squares.
They are not required for exceptional work and cannot make a dullard into a master.

http://www.kevinleeluthier.com/stradivari_tools/Stradivari_Marking.jpg

[Rich Engelhardt]

The are not required for exceptional work and cannot make a dullard into a master.

While I agree 100% w/the idea that it's the "hand that uses the tool, not the tool itself" idea - top quality tools, such as Starrett make things a lot easier for us dullards! ;)

[Glen Butler]

I have a good General 12" combination square and a smaller 6" Starrett. I use both for very accurate machinery setup. Often a 90 deg. setting must be interpolated because daylight still shows between the finely ground blade of the square and a *flat* saw blade. But by a bit if trial and error, usable 90 deg. settings can be had with table saw, radial arm saw, chop saw, and shaper; Not only between miter gauge and blade, but also vertically, between table surface and blade.


Finally someone else out there mentions the General 12" combi. They make two. The blue one is a nicer tool, but is still only around $30. I'd wager its just as accurate as a starrett. I see no reason to spend that much money, but for 30 bones its worth having one. I use it every project, all the time. Layout, scribe lines, tool setup up.

[Neil Brooks]

Finally someone else out there mentions the General 12" combi. They make two. The blue one is a nicer tool, but is still only around $30. I'd wager its just as accurate as a starrett. I see no reason to spend that much money, but for 30 bones its worth having one. I use it every project, all the time. Layout, scribe lines, tool setup up.

"Setup up??"

I like it :)

Nobody has to explain, around here, what makes tool A "worth" more than tool B, but ...

I have a General AND a Starrett -- of different lengths.

For me, it's a lot like the world of bicycling (or a hundred other examples):

The lower end components may do the same job, but ... the precision with which the higher-end components are made is a thing of beauty to behold, may give them longer service lives, and -- for those with more $$ than sense (like me!) -- give a "joy of ownership and operation" that lesser tools simply do not.

I'll let you know in 30yrs, but ... I don't think my General is going to hold its accuracy for NEARLY as long as will the Starrett.

I think the Starrett could be accurate when my step grandson picks it up ;)

My $0.02. YMMV.

[Glen Butler]

I am all for a fine tool. With many things I have more $$ than sense. Like Cycling:) Oh the $$$$ I have dropped there. I have never handled a starrett so the fact that you own both and still vote starrett maybe I should. It is fun thinking about posterity handling and using ones tools. I just fear rolling over in my grave while they abuse them because they didn't have to earn them.

[Neil Brooks]

Glen-

VERY well said !!

[Larry Edgerton]

"



For me, it's a lot like the world of bicycling (or a hundred other examples):

.

Exactly! My last bike was a Colnago Master Light, signed by Ernesto himself with that crazy paint job for an extra $220, and full Campy Record Ergo,ti Speedplays and sewups. Most people don't get it.....

I use Mitatoyo in the shop, and the difference in confidence and crispness between that and the General that I carry every day is definately noticable. I would not subject a high end square to site work, but I wish I could in clear conscience.......