View Full Version : best way to get a perfectly square piece of wood.

04-06-2004, 07:57 PM
Ok... Stupid question but I figured I would ask. What is the best way to get perfect 90 degree corners on a piece of wood? In other words what is the favored tool to complete this sort of task.

Anyway, thanks all!

04-06-2004, 08:07 PM
Hands down, table saw. Though not a must, it would preferably be done with a 'sled' for cutting sheet goods that is fixed at 90 degrees.

04-06-2004, 08:08 PM
there is not one, but 3 tools involved to get it perfect and then you need some practice. You need to joint edge and face then table saw, plaine and then joint the other edge. However depending on the size of your piece of wood you can do it all on a tablesaw.

04-06-2004, 08:14 PM

Hrm you can use almost anything to do this, depending on the size of stock you're cutting and if it has a straight edge.

Assuming it does a well setup mitre saw will give a perfectly square chop but you're limited to the depth of the piece, and a good sturdy mitre attachment on a table saw will do the same only give you all but unlimited capacity for cuts, but even something as simple as a T-Square to mark your line and a handsaw/jigsaw/circular saw will work.

Before I had many tools, I'd simply use a clamped steel straight edge (in my case I used builders metal supports) as a guide and my circular saw.

If it cuts wood, theres a way to get a straight line, and from this any dimensioned wood that you require.

Did you have anything more specific in mind or just wondering?


04-06-2004, 09:49 PM
There was a nice article in "Fine Woodworking" a few months back. The method the writer used was quite involved and time consuming.

Rough cut all pieces leaving 1/4 in or so on all surfaces. Stack the pieces with air space all around the pieces on the work bench and let some time pass. a week or a month. Even overnight will give the wood a chance to stress releive, THEN, finish cut all dimensions to size.

He used a method called FEE. Faces, Edges, and Ends. In that order!

First, Joint one face.
Second, put jointed face against the jointer fence and joint One edge.
Third, Plane opposite face parallel to jointed face
Fourth, table saw to rip opposite edge parallel to jointed edge.
Fifth, cross cut ends to length.

One thing I have found, is that if the faces and edges are true, then, there is a better chance to get the ends true.

There may be some better suggestions out there, but this one works for me. It is also the same method we used is my woodworking class at evening school tonight.

04-06-2004, 10:45 PM
What he said (arcticfox46):)


04-07-2004, 05:30 AM
Leo's mention of FWWing was ironic. it's one of the few articles I've read lately. I find the majority to be over the top. Any way the point I wanted to add that I believe the article missed is that if you go through such a painstakingly process to do this, be sure to use the piece relatively soon. Wood is very dynamic in that what is square at this machine shop level or degree may very well be out a few thou's tommorow. A little cynicism on my part, yes I know.
Reality is though, that the majority of the folks here are dealing in pencil line tolerances. Unless your going to mark with a razor sharp marking knives, I think for most projects working to a tolerance of 1/64 is obtainable and practical. And with benchtop tools a 32nd may keep you from pulling your hair out.


04-07-2004, 11:45 AM
As stated, the answer is to use a jointer, thickness planer and another tool to make the fourth face parallel or perpendicular the one of the other three, that could be a jointer, planer or table saw. Then you of course need to cut the ends square to the length of the piece.

Although I have been doing woodworking for 25 years, at different levels, I finally was able to reach my level of perfection only this week while doing a face frame for my wife's soon-to-be computer desk. And it took the right tools for me to do it.

First, I started with a machined draftsman's triangle. I found my steel adjustable machinist's square to be a bit off. Then I squared up the fence of my old jointer with that. The second tool that helped me reach perfection was the Delta 580 thickness planer I purchased 2 weeks ago. If you are using boards that are narrow compared to the thickness, you can stand them on edge, after thickness planing, even ganged parallel to each other, to finish the fourth face after ripping them slightly oversize on the table saw. Be sure to put the jointed (square) edge down. By doing this you can really tweak the width even tighter than a table saw.

The final trick was to forget trying to use my chop saw (a Milwaukee) to put a perpendicular end on the board. I went to my table saw (a Grizzly) and squared up my blade to the table with the triangle, then the miter gage to the table slot. Here, I used my new Incra 1000 miter gage which was dead on out of the box and didn't require any adjustment. I loved the Incra's flip stop which allowed me to get repeatable rail and stile lengths.

I considered dowels and biscuits for assemblying the face frame, but opted for going with pocket screwed joints using the small Kreg portable unit (Pocket Rocket?) I was glad I did, as my first experience with the technique sold me. (Also my first experience with a stand-alone face frame.) On the back of the frame, the pockets are hidden, but I opted to use biscuits to mount the frame to the case where the pockets would have otherwise been visible. Once I socked the screws down on the glued joint and held it up, measured it and checked it for square, and ran my hands over the smooth wood, I felt I have perfected my technique. With what I learned and the equipment I have, I can now do some accurate wood working.

Sorry I got a little off topic, but it gets back to cutting square.

07-12-2004, 04:13 AM
The fact of the matter is, you may check a piece of wood to see if it's square, or is it?

We must ask ourselves if our square is really square. Trust me, last time I went to H.D. looking to buy a framing square, I went through 8 of them until I found one that was actually SQUARE. So that sleigh bed that you THINK is square, may not be square. It could be as square as the tool you used to make it square.



07-12-2004, 09:04 AM
Though I probably have 10 or twelve different "squares" in my shop, from a little combination square, to larger combination squares with multiple heads, to speed squares and on up to rafter squares, I have three that I know are right on square. I have an old rafter square that checks to within a minute of being right on, a metal speed square that over its 6" length is razer close, and a new machinist's square which checks to the speed square. For every setup requiring accuracy, I use one of these three squares.

So how do you get a perfect square cut? You first use a machine or device that has no slop. If your miter gauge wiggles in the slot at all, you gotta figure out something else. If your chop saw has any wiggle, use something else. In addition to having no slop, you must have the ability to either move the workpiece through the cutter in a line parallel to the cutter, or to move the cutter into the piece on a plane parallel to the cutting line of the cutter. You also need the ability to make the cut on a plane perpendicular to the face of the workpiece.

Once you have a setup that has no play, you set it up using a known square index.

Or, you can cut it close and use another device to adjust it to perfect (perfect being a relative term). One device that is used by extensively by picture framers is a miter trimmer. This is a big guillotine like device that uses a large triangular shaped very sharp blade to slice the wood. The old timers using hand saws would use a shooting board and hand plane to clean up and square the ends of pieces after cutting them close with a handsaw.

So, what tool is the favorite for doing this job. Every woodworker has his/her own favorite and it is generally the tool they own which can be set up the most accurately and maintain this accuracy.

Also remember that when dealing with joints that form a closed polygon, the accuracy of the lengths of the pieces forming the polygon are as important as the angles cut on their ends.

Steven Wilson
07-12-2004, 10:23 AM
For sheet goods and glued up panels I use a sliding table saw and clamp the wood down. I can get the total error in a 2x2' panel to around .005" (which is .005" error in 8') which I can measure using the 5 sided cut but can't measure with any square in my shop.

07-12-2004, 11:13 AM
Or, you could just forget all this and cover it up with the finish. :)

07-12-2004, 10:06 PM
Interesting that we're so bored with current topics of discussion that we're actually hauling up some stuff that's MONTHS old just to have things to talk about...

Could it be that we spend too little time in the shop? :) How else would we find topics this old?

-- Tim --

Know deposit,
Know return.

07-12-2004, 10:19 PM

If you think the topics at hand are above you or you're bored, the please offer some questions to the forum so we may be all enlightened by your superior expertise. :)