Introduction: Clamping at ANY Angle

Clamps are a woodworker's best friend... until you need to clamp two non-parallel surfaces. There are specialty clamps for picture frames, cabinet making, and other 90 degree applications but you'll also find yourself facing a 45 degree or 30 degree angle every so often.

When faced with a 45 degree angle, if you're like me, you'll first try to use a bar clamp with a pivoting head. Friction will allow the clamp to work if your surfaces are close to parallel or if your wood is rather rough. Thinking yourself rather clever you'll then attempt a glue-up and the now-greatly-slicker surfaces will slide all over when you try to tighten the clamp.

A scrap piece of wood, a few basic tools, and 5 minutes are all you need to create a custom v-block for securely clamping any angle!

Step 1: Grab a Scrap Piece of Wood and a Piece of Paper

You'll need-

  • A scrap piece of wood (mine was approximatly 1.5" x .75" by 1 ft)
  • A piece of paper
  • A pencil
  • A saw


  • Power Drill

Step 2: Create a 45 Degree Angle

Fold the piece of paper to form a 45 degree angle. Lift one corner along the short edge of the paper and bring it to the opposite long edge, lining up the short edge of the paper with the long edge.

Note: This is a great trick to quickly check angles around your workshop. Often a folded piece of paper is better than a metal angle when checking the alignment angle of a blade (which might be knicked) or reaching in between delicate components.

Step 3: Mark a 90 Degree V

Line up one edge of your 45 degree angle with the bottom edge of the scrap board. Mark with a pencil along the folded edge (you could also use the other edge of the 45 degree angle but the pencil will travel better against the fold). Flip your template over horizontally and mark a second line.

Make sure that the intersection point between your first and second line is approximately in the center of your scrap board. If the V shape is too deep, your block might split later under clamping pressure.

Step 4: Mark the Edge

Draw a straight line so the V shape will be approximately in the middle of the final block. If you love exact angles, you can use the corner of your piece of paper to draw a vertical line 90 degrees from the bottom edge of the scrap board.

Step 5: Optional: Drill at the Intersection

Use a drill to make a hole at the intersection of your two 45 degree lines. I used a 3/16" drill bit but you can use whatever looks proportional to you. The hole creates clearance space at the intersection of the V block and will help protect delicate corners (especially mitered corners that are slightly off).

Step 6: Cut Out the V and Cut Off the V Block

Use a saw to cut off the section of your scrap lumber that will become the v block. Mine ended up being a little over 3 inches but yours will vary depending on the depth of your V and desired angle. Next, cut each side of the v shape. Be sure to keep your blade on the inside of your pencil lines to make the drilled hole as effective as possible.

Step 7: Clamp at 45 Degrees! (or Any Other Angle)

Clean up the edges of your v block with some sandpaper and clamp away!

You can use this technique to make a custom v block to clamp against any angle with a little math (or a protractor).
I'd love to see your results if this helped you out!

Happy making!


Willyco2608 made it!(author)2017-01-04

great, thanks for sharing

Raitis made it!(author)2016-10-16

Been thinking about making something like this for a while. How does it hold up when clamping a diagonal that long? Doesn't it spread the walls apart anyway?

marteen1 made it!(author)2016-10-18

You can simply make a larger version off her design, so it has more 'backing' on it. Basically, if the backing goes up higher, you'll have more of a plane to brace against. Good for larger projects or for wood that is flexible (which would require a rigid backing).

As of now the backing is a bit low, but that is all that she needed in this case. Her cuts of wood are straight, rigid, and she double-checked with a square.

WillC_instructables made it!(author)2016-10-20

Good idea.

mikeasaurus made it!(author)2016-10-18

Just add another clamp on the diagonal to keep it all together.

Clamps on clamps on clamps! :)

Raitis made it!(author)2016-10-19

Of course, exactly why there are never enough clamps in the workshop!

marteen1 - sure, yet then there's the thing of stock size needed to cut such a thing. I think I have one idea in mind though - a bigger version with steps for clamsp should work.

robbadooz made it!(author)2016-10-19

Great idea! Now, why didn't I think of that? Thanks!

danzo321 made it!(author)2016-10-18

In regular woodworking, you secure the diagonal piece with glue plus 18 ga nailgun. If you clamp a diagonal into a 90º, you have to be spreading the angle. The angle blocks are great but not in this construction.

marteen1 made it!(author)2016-10-18

You think so? This is the perfect time for the angle blocks.

The vertical wood piece would have to bend before that angle would spread. And if it was to bend, then your clamping it too hard.

danzo321 made it!(author)2016-10-18

And it strikes me that any but the lightest clamping will bend the 90º to 93, 95, 97º.. Keep a good square on the angle and give it a try. You might also create a double hooked piece that prevents spreading. Could also place the rt-angle assembly facedown on a piece of plywood with wood strips hard against both sides so it can't spread.

marteen1 made it!(author)2016-10-19

Double-hooked is a great idea too, I like that! Never one way to do things.

I get what your saying, but clamping 90 degree will not spread with a proper backing/support, because it can't expand/spread if there is something backing it on both sides of the vertical/horizontal planes.

inchman made it!(author)2016-10-19

First, this is a neat 'ible. But I really LOVE the idea of using paper for the angles. That is worth the 'ible by itself!

Thanks for sharing.

mikeasaurus made it!(author)2016-10-19

It's the simple things. I love tips like these!

mbonifax made it!(author)2016-10-19


So easy... so well explaned... so usefull..

redcanary16 made it!(author)2016-10-18

A nice, simple fix for an awkward clamping problem. As someone pointed out below, in the the clamping example shown it would indeed be advisable to clamp the two perpendicular boards so that the force created, whilst tightening the diagonal brace, couldn't push them out of square. That's not because of any deficiency with the corner clamp of course as any pressure applied in this way would act to force the members apart.

Anyway, it was also very pleasing to read an eloquent instructable - call me sad if you will, but a good grasp of grammar and proper punctuation pleases me enormously! Thank you for sharing. ?

john171 made it!(author)2016-10-18

Very nice 'ible....BTW, that hole also helps relieve the pressure and keeps the block from splitting. As for spreading, make the block a bit bigger for those larger glue ups. Seal them and tag with the angle

muadibe made it!(author)2016-10-18

A very useful tip, Thank you.

CharlesAndSue made it!(author)2016-10-18

Great tips. Sometimes the simplest things are the best. We'll done. The clearance hole is a great idea for better corners.

HeatherT4 made it!(author)2016-10-18

Thank you! What a great tip!!! Way cheaper too. What do you think of putting a finish on then so they resist glue?

mikeasaurus made it!(author)2016-10-18

Not a bad idea. An alternative would be any think sacrificial piece, like wax paper or even lining it with thin sheet metal.

HeatherT4 made it!(author)2016-10-18

Also, do think if you use the corner cutoff (like cut the triangle all the way through), it could be used for inside clamping a 45• angle frame? Does that even make sense? Lol

Bill+WW made it!(author)2016-10-18

Very nice, and drilling the hole in the corner is a valuable feature.
For those nice tight glue joints you made, you do not need much clamping force so "spreading the angle" should not be a problem, and you have the metal square behind to check.
Good work, thank you.

ji52skdoo made it!(author)2016-10-18

Nicely done! Who'd a thunk?

chefspenser made it!(author)2016-10-18

Excellent! Thank you very much.

demxod8 made it!(author)2016-10-18

Very ingenious and simple. It would made life easier on the last little project I did. Thank you.

Benybe made it!(author)2016-10-18


TorBoy9 made it!(author)2016-10-18

Great trick. Thanks for the 'ible.

jarheadpilot82 made it!(author)2016-10-18

If you do a lot of woodworking, it might not be a bad idea to make a couple of these ahead of time - 30º, 45º, 60º - for example, just put them on your shelf, and then you will have them ready when you need them! A great idea!

MikeD50 made it!(author)2016-10-18

This 'ible is a gem! The new trick for me was the drill in the corner ... enlightning!

-> Favourites!

Thanks for sharing

tytower made it!(author)2016-10-17

Ha never thought of this and it is a frequent problem in boatbuilding especially

JGDean made it!(author)2016-10-17

Great method for 45 and 90 degree corners! If you need to measure or mark other angles, IGaging makes several sizes of digital protractors that are generally available on ebay for under $20. Also available from Amazon at slightly higher cost. Accuracy is excellent - better than 0.1 degrees.

Digital Protractor.jpg
cyberraxx made it!(author)2016-10-16

The paper trick!!! i completely forgot it and you've just reminded me of how to draw 45 degree angles.

all this time I've used a ruler to work it out yet all I had to do was fold some paper.

you sir have are a god send.

jhawkins14 made it!(author)2016-10-15

I am gonna have to come back and read this again someday and gonna be glad I favorited it

DIY+Hacks+and+How+Tos made it!(author)2016-10-15

Clever trick. I think that this has the potential to greatly improve my wood working proficiency.

About This Instructable




Bio: I love working at the intersection between design, material science, function, and delight! I like thinking about fashion, history, and art, and about how we ... More »
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