ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

How to Sew Perfect Pinwheels

Updated on November 3, 2014

Perfect Pinwheels Every Time

How to make a sawtooth square
How to make a sawtooth square

Quarter Pinwheels, Sawtooth Squares or Half Triangle Squares

For a quilter like me, there is something extremely satisfying about being able to quickly produce a basic quilt block that can be used to complete many projects in a wide variety of ways.

On the face of it, a half triangle square is a fairly easy thing. You cut out 2 right-angle triangles the same size, and them sew them together, right? Since I’m a fairly impatient sewer/quilter, this was my preferred method for too many years to go into. Finally, after yet another failed attempt to produce perfect pinwheels, I started my search for the easiest (and quickest) way to sew together those pesky triangles without stretching them beyond recognition from point to point.

Once I’d gathered the little snippets of information located in my search and put them in one easy to find location (my computer) it occurred to me that if I was doing it, there are probably other frustrated quilters searching for exactly the same answers. This hub is the result. The intention is to provide you with instructions that are easy to store and quick to find, every time you need them, so that you can get on with your next great project!!!

SawTooth Square

Sawtooth square a quilter's basic block that can be used for sew many projects they can't begin to be listed here.
Sawtooth square a quilter's basic block that can be used for sew many projects they can't begin to be listed here.

First cuts:

To decide on the size of square you need to start with, simply add 7/8 of an inch to the size you want your finished Sawtooth square to be. Put another way, if you want a 2" Sawtooth square, cut squares from your selected colours of 2 7/8". This is an excellent time to use a rotary cutter.  If you stack your fabric together in the light and dark combination you’ll be making the Sawtooth square from, the two base squares will be compressed together by the cutting process, reducing slippage to some degree.  Don't forget to put the fabric right sides together, this is an important point that caused me to do some complaining when I wasn't as careful as I should have been during one cutting out session.

Use a pencil for the BEST results
Use a pencil for the BEST results

Mark things up a little:

Most instructions tell you to use a quilter’s pencil to mark your blocks. This is the best advice, but if your home sewing area looks anything like mine, you'll be relieved to know that it is “OK” to use a regular pencil. Grabbing a pen by accident is marginal, but you will be cutting along any lines you make at this point so it can be overlooked.  Any pen marks will be hidden on the inside of your finished product at the end of the day.   BUT, and this is a BIG but, you need to be aware that if you use a gel pen, there still may be enough of the ink left in the cloth to seep into your finished block when you steam press the square and that can end up being bad.

What ever you choose for marking, draw a diagonal line from one corner to the opposite one, on the wrong side of the lighter of the two squares that you will be joining.

(A really nifty trick here is placing 220 grit sand paper under the squares to keep them from stretching as you draw the lines. After all the whole point of joining the triangles in this manner is to avoid stretching either of them across the diagonal more than you have to!)

Start putting things together:

With the right sides together, layer each light square (in my illustrations the yellow squares are lighter) on top of a darker square (green in illustrations) and sew each pair together with two seams, stitching 1/4" from the drawn line - one line of stitching on either side of the diagonal.

It can save time to chain piece these pairs, that is running them through your sewing machine one after the other without lifting the presser foot or clipping threads between units.  First, sew along one side of the drawn lines, start again from the beginning and sew along the other side of the line.  Clip the connecting threads between the pairs.

Pinwheel Block

Made from 4 small sawtooth square blocks, each rotated 90 degrees from starting block.
Made from 4 small sawtooth square blocks, each rotated 90 degrees from starting block.

Cut and Press:

Cut a pair of the sewn squares apart on the marked diagonal line to show two triangles. Open the triangles out to reveal a perfect square with two half triangles. Press each half triangle square thoroughly and then trim the finished square so that it is exactly the size you were expecting.

Now you have some perfect squares that are ready to either form some pinwheels or star in a quilt of their own. The picture shows 4 of these saw-tooth square blocks (or half triangle squares put together to form pinwheels.

Mini Quilt layout using 4" pinwheel blocks

Ready to sew together!!
Ready to sew together!!


Thanks for reading this. Look for more sewing and quilting how to hubs in future days because I'm always sewing some snippets together to create something new.

A friend very kindly gave me a huge load of drapery sample books to either use or take to the dump.  Since I am a confirmed fabricholic, even the thought of trashing all those amazing little bits of fabric was painful.  Right now I have 50 beautiful pieces that I'm working my way through, one piece at a time.

Sew On!


    0 of 8192 characters used
    Post Comment

    • Practical Paws profile image

      Debra Hine 5 years ago from Longueuil, Quebec

      I've struggled with this question many times and tried everything I can think of to reduce the bulk at the pinwheel centers. I get the best results when I iron the seams open and then cut off the excess points of fabric that usually extend past each side of the square. Very thorough steam pressing really helps compact 100% cotton. It may be tedious doing all that pressing - to say nothing of scorched fingers if your iron is set on the cotton setting a but the end result is really worth it.

    • profile image

      Cindy 7 years ago

      Are we ironing the seams OPEN or to the darker side, as one book suggests?? By the time Iconnect all of these triangls in the center to form the pinwheel, there is a lot of bulk in the center!! I "clip" the wings as I go along, sewing each triangle to the other...please advise!!

    • GiftedGrandma profile image

      GiftedGrandma 8 years ago from USA

      Great instructions...add it to some of the things I plan to try someday :O)