Half Square Triangles (HSTs): 8 at a Time!

on January 7 | in Sewing Tutorials + Patterns | by | with 25 Comments

Lindsay Conner writes all about her sewing and more at Lindsay Sews. She’s also co-founder of the popular Craft Buds site and editor at CraftFoxes. Learn more about Lindsay in her introduction, and don’t miss the HST Quilt Block PDF included below. She also has a link to the Brackets Quilt and a mini tutorial she created based on the blocks she made with today’s tutorial.

We asked Lindsay to share her technique for making Half Square Triangles here today. (Half Square Triangles are also known as HSTs.) Lindsay’s tutorial will have you sewing up eight half square triangles at a time! Imagine what you can create…

Hello! I’m Lindsay, and I’m excited to share my new favorite way to make half-square triangles (HSTs), a basic quilting unit that is used in many quilt blocks. In the past, I’ve made HSTs one, two or four at a time. But did you know that there’s an easy to sew HSTs eight at a time?

With this time-saving method, you’ll be able to finish your bee blocks in record time! Let’s get started.

Materials for One Block:

  • Four 9” fabric squares in different prints
  • Rotary cutter, ruler and mat
  • Pencil or pen
  • Sewing machine, iron, thread and sewing pins

Block Size: 12.5” unfinished OR 14.5” unfinished. Both sizes of blocks have 16 HSTs per block.

Size Options:
* Trim HSTs to 3.5” for 12.5” unfinished block. Good for swaps and bees requiring a standard-size quilt block.
* Trim HSTs to 4″ for 14.5″ unfinished block. Good for making a larger quilt and maximizing your fabric.

To get started, choose two fabrics and cut them into 9” squares. I chose one light and one darker fabric for contrast. Tip: You can easily get four squares from one fat quarter, when calculating fabric needed for a quilt top.

Stack the fabric squares with right sides facing to the middle. With your pen or pencil and a ruler, draw straight lines from corner to corner, making an “X.” You’ll draw on the wrong side of just one of your fabric squares.

Pin the squares together to avoid shifting, and stitch lines 1/4” to the right and left of each of your marked lines.

Before you do any cutting, use your ruler and pen to draw a vertical line through the center of your fabric, and then draw a horizontal line the same way. You should now see an “X” (with stitch lines) and a plus sign.

Use your ruler and rotary cutter to slice along the lines you just drew (the plus sign). You should now see four equal quadrants, each with stitch lines going from corner to corner.

Cut along the marked line of each quadrant, yielding two HSTs.

Open your HSTs and press the seam with an iron. I like to press my seams open, so they stay flatter in the finished quilt block, but you could also press your seams toward the darker fabric.

Flip over your HSTs, and use a ruler with a 45-degree mark to trim the blocks. Align the diagonal of the block with the 45-degree mark on your ruler, and trim off the corners and edges.

Trim Options:
* Trim to 4” x 4”: I trimmed my blocks to 4” each, to make a quilt as large as possible, thus maximizing my fabric.
*Trim to 3.5” x 3.5”: You may want to trim your blocks to 3.5”, which yields a 12.5” unfinished block. This is a common size for quilt blocks, and works well for bees and sampler quilts.

You should now have eight half-square triangles, enough for half of your block.

Repeat this process with two additional 9” fabric squares. Here is my second set of eight HSTs, made from contrasting fabrics.

Here is my 14.5” x 14.5” quilt block! I think this design looks like brackets, and I’ve used this color scheme to piece together a quilt.

If you’d like to stop by my blog, I’m sharing my Brackets Quilt and a mini tutorial, inspired by the block above!

Once you’ve completed a set of 16 HSTs, you have enough to make a good variety of quilt blocks. I’ve put together a free PDF showing eight sample blocks you could try with your half-square triangles. The number of designs you can make with your HSTs is nearly endless!

I hope you’ve enjoyed learning how to make half-square triangles eight at a time.

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25 Responses to Half Square Triangles (HSTs): 8 at a Time!

  1. Tracy Clark says:

    Thank-you! I’m building blocks using this method!

  2. Kerrin says:

    I will definitely use this! Thanks for posting!

  3. Lindsay says:

    Sherrill, I think 6″ would work! Multiply the size HST you want (in your case, 2.5) times 2.25 and round up to the nearest whole number to get the size of your starting square.

    So 2.5″ x 2.25 = 5.625 and round up to 6″ to get your starting square.

  4. Sherrill says:

    OK, so if you wanted 2 1/2″ tris, what size large square would you start with? 6, 7, 8? Can you tell math is NOT my forte? Thanks for the great idea.

  5. This is just fantastic – thank you so much!

  6. Sarah says:

    I juuuuust learned how to make four at a time and I thought it was a revelation. What am I going to do now?!?!

  7. Karissa says:

    That is absolutely brilliant! Thank you for sharing, I will definitely be using this technique!

  8. Dianne Hiller says:

    Great technique!

  9. Marcelle says:

    So very helpful! Thank you so much for sharing.

  10. Julie says:

    Wow, that is really clever. All the years I watched my mom making quilts, I never saw her do this. Boy, she could have tripled her time easily. I gotta tell here about this even tho she doesn’t quilt anymore. Thanks.

  11. Stephanie o in ct says:

    Love this! There are some projects that I have been putti g off because I didn’t want to have to do these one at a time. Genius- I would never have thought of this . THANK YOU

  12. Gah! This is SO clever. I am totally trying this next time I need a bunch of HSTs. Thank you!! : )

  13. Bethany says:

    That is very cool…triangles have always been difficult for me, that seems pretty easy to do it all right and the same!! YEAH!

  14. CitricSugar says:

    I figured this one out last year when trying to make matching table toppers for my sister’s bedroom with charm squares. Glad to see a tut for it so I don’t have to try to explain it to other people – I can just send them here. Thanks!

  15. Lauren aka Giddy99 says:

    That is AMAZING and GENIUS! Thanks for sharing!

  16. Bente says:

    Thanks so much, great tutorial!!!

  17. Alli says:

    That is a super cool tutorial! Thanks for sharing! 🙂

  18. VickiT says:

    Great tutorial. Thank you. I need to try this later tonight.

  19. Heather L says:

    That’s awesome! Can’t wait to try it!

  20. Megan says:

    This blew my mind! Thanks for sharing.

  21. becky says:

    i love this tutorial! Thanks for sharing it. I just posted on how to use your UFO Quilt blocks using and some of the blocks were half square triangles. Just in case you don’t have any in your stash, this is a great solution! check it out here: http://www.patchworkposse.com/blog/2013/01/signature-quilt-tutorial-52-ufo-quilt-block/

  22. Joanna in NY says:

    Thanks for the free tutorial. I’ve never made quilt before…this tutorial inspires me to try.

  23. Karee says:

    Love this tut. Love HSTs. Going to crack open a layer cake and experiment. Thank you!

  24. Tina says:

    I have a whole chart for different sized HST’s doing this method if you/anyone is interested in it. You can email me at torlita@comcast.net. Please put HST in your subject line so I don’t delete your message.

  25. Anna says:

    Great technique, Lindsay! I will definitely be trying this in the future. Thank you for sharing.

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