8 Half Square Triangles At Once – Tutorial

8 half square triangles sewn at one time? Can that really even happen? I am one that sews fast. The faster the better. I even have been accused to shaking the table with my sewing machine speed.

This is the neatest little trick ever! Half square triangles can get a little boring. Especially if you need a lot of them! I am always on the lookout for new ways to speed up the sewing and this one is my current favorite.

Materials Needed:

• 1 Background
• 1 Other
• It doesn’t matter what size you start with, just as long as they are equal in size. For this tutorial I used 2– 9″ X 9″ squares.
• These ended up at 4″ X 4″ unfinished. They could also be squared up to a smaller size if needed. 3 1/2″ square would equal to a 12 1/2″ unfinished quilt block if you were to sew all 8 of them together for a quilt block.
• Fabric: Coordinating fabric and optional scraps
• Tools: Rotary cutter, cutting mat, ruler, sewing machine
• Thread: Matching or contrasting
• Extras: Pins, iron, marking tools (optional)

Tips & Tricks:

1. Use starch or fabric sizing:
This helps reduce fabric stretching and keeps your squares crisp for accurate sewing and cutting.

2. Chain piece for efficiency:
Sew all your seams on one line, then rotate and do the others—saves time and thread!

3. Use a scant ¼” seam:
A slightly smaller seam allows for cleaner trimming and helps your finished blocks stay true to size.

4. Press before cutting:
Give your fabric a quick press after sewing but before slicing—it helps lock the stitches in place.

5. Rotate your mat, not your fabric:
When making your final diagonal cuts, rotating your cutting mat instead of shifting the fabric helps keep everything aligned.

6. Square up every block:
Even small trimming makes a big difference in the final quilt layout—don’t skip this step!

8 Half Square Triangles At Once Instructions:

1)  Lay your squares right sides together

2)  With a ruler and pencil, mark a line from corner to corner. Repeat for opposite corner.

3)  Mark the middle of the square on either side also

4)  Sew a SCANT 1/4″ from the CORNER TO CORNER lines

5)  Sew again on the other side of the drawn line

6)  Repeat steps 4 and 5 for the other corner to corner line

7)  Cut on the drawn lines

8)  Iron and square to size

9)  If you have a project for them to go into….you are set to go. If not, you can play with the layout of the squares.

Here Are 4 Variations:

Grab all 4 methods for making HST:

More info on the half square triangle – all 4 methods and a calculator that you can use to customize your size!

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Additional Half Square Resources

• Free Printable Half Square Triangles
• How to Use Half Square Triangle Paper
• Squaring up Half Square Triangles with the Bloc Loc Ruler
• How To Sew Half Square Triangles With Fabric Strips Or Jelly Rolls
• Charm Packs And Half Square Triangles Paper Templates

Frequently Asked Questions

1. How many squares do I need to start the process?
Use two equal-sized fabric squares—common starting sizes include 9″ (makes 4″ HSTs) or any size you choose

2. What are the basic steps for the technique?
Stack right sides together, draw diagonal lines corner-to-corner, sew a scant ¼″ on both sides of each diagonal, cut along lines, press and trim

3. What size are the resulting HSTs?
Depending on your starting size—for example, two 9″ squares yield eight 4″ unfinished HSTs (4½″ before trimming)

4. Is this faster than traditional methods?
Yes—this method creates eight HSTs in one batch, making it a much quicker alternative to the usual two or four-at-a-time methods

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