Sewing a snap takes about five minutes once you have the snap and a needle threaded
A snap is two small metal discs—one with a raised center post, one with a recessed cup—that press together to fasten fabric. You sew each piece separately to opposite sides of the fabric, usually on a garment opening or pocket. The post side goes on top (the side you see), and the cup side goes underneath. Both pieces are sewn using the same method: a series of small stitches through the holes around the edge of each disc.
You will need a needle, thread that matches your fabric, scissors, and the snap itself. A thimble is optional but helpful if you are sewing through heavy fabric. The entire process—sewing both the post and cup—takes about five minutes once you have everything ready.
Key Takeaways
- The post side of the snap (the raised center) faces outward on the top layer of fabric; the cup side (the recessed center) faces outward on the bottom layer.
- Thread your needle, knot the end, and push the needle up through one of the four holes in the snap disc from underneath the fabric.
- Stitch around the snap by passing the needle through each hole twice, keeping stitches small and tight so the snap will not pull loose.
- Sew the post side first, then flip the garment and sew the cup side using the same technique.
- Trim the thread close to the fabric when you are finished, and test the snap by pressing it together firmly.
Positioning the snap on your fabric
Decide where you want the snap to sit. On a shirt or jacket, this is usually at the center front where the two sides of fabric meet, or on a pocket flap. Mark the spot lightly with a pencil or fabric pen if the fabric is dark, or use a pin to mark the center point.
Place the post side (the one with the raised bump in the middle) on the top layer of fabric, facing outward. The cup side will go on the underside of the fabric, facing outward as well. If you are working on a two-layer garment like a shirt front, the post goes on the right side and the cup goes on the left side, so they line up when you press the fabric together.
Threading your needle and starting the stitch
Cut an arm's length of thread and thread it through the needle. Tie a knot at the end. Push the needle up through the fabric from underneath, coming up through one of the four holes in the snap disc. Pull the thread until the knot catches on the underside of the fabric.
You are now ready to stitch. The snap will not move if you keep your stitches small and go through each hole at least twice. Do not pull the thread so tight that you pucker the fabric, but do pull it snug enough that the snap sits flat.
Stitching around the snap
Pass the needle down through the same hole you came up through, then push it back up through the next hole clockwise. Pull the thread snug. Repeat this pattern—down through one hole, up through the next—until you have gone around the entire snap and returned to your starting hole.
Go around a second time using the same holes. This double stitching keeps the snap from pulling loose during washing or wear. Your stitches should be small (about the size of a grain of rice) and close together. If you see gaps between stitches, you have gone too fast or pulled too loose.
Finishing the first side and moving to the second
When you have stitched around the snap twice, push the needle to the underside of the fabric and tie a knot. Trim the thread close to the fabric with scissors. The post side is now find.
Flip the garment or fabric piece over so the other side faces you. Position the cup side of the snap (the one with the recessed center) directly underneath where you just stitched the post. It should line up perfectly. Thread a new needle, knot the end, and repeat the same stitching process—up through a hole, down through the same hole, up through the next hole, and around twice.
Testing the snap and common mistakes to avoid
Once both sides are stitched, press the two halves of the snap together firmly. They should click or snap together with a solid feel. If the snap feels loose or does not hold, one or both sides may not be stitched tightly enough. You can add a few more stitches through any holes that look loose.
The most common mistake is stitching too loosely. If the snap wiggles when you press it, the thread is not tight enough. Another mistake is skipping holes or stitching only once around instead of twice. A third is sewing the post and cup on the same side of the fabric by accident—double-check that the post faces outward on top and the cup faces outward on the bottom before you start.
Choosing the right thread and needle for your fabric
Use thread that matches your fabric color so the stitches blend in. For lightweight fabrics like cotton or linen, a standard sewing needle (size 70/10 or 80/12) works fine. For heavier fabrics like denim or canvas, use a stronger needle (size 90/14 or 100/16) so you do not bend or break it while pushing through the snap holes.
If you are sewing through very thick fabric and the needle is hard to push, a thimble on your middle finger will protect your skin and give you better leverage. Some people also use a small pair of pliers to pull the needle through if it gets stuck, but this is only necessary on very heavy materials.
Frequently Asked Questions
Can I sew a snap by hand if I have never sewn before?
Yes. Snaps are one of the easiest hand-sewing projects because the holes are already marked for you and the stitches do not have to be perfect—they just have to be tight. If you can thread a needle and tie a knot, you can sew on a snap.
What if I sew the post and cup on the same side by mistake?
Cut the thread and remove the stitches with a seam ripper or small scissors. Flip the snap over and sew it to the correct side. It is faster to fix it now than to deal with a snap that does not work.
How many times should I stitch around the snap?
Go around at least twice—once through each hole, then a second time through the same holes. For garments that will get heavy wear or frequent washing, a third pass adds extra security without being necessary.
Can I use a sewing machine to attach a snap?
Most home sewing machines cannot stitch through the metal snap holes safely—the needle can break or bend. Hand sewing is the standard method. Some industrial machines have snap-setting attachments, but these are not common in home sewing.
What if the snap keeps coming undone after I wash the garment?
The thread may not be tight enough, or you may have stitched only once around. Remove the snap, cut out the old stitches, and sew it on again using the double-stitching method. Make sure each stitch is snug and the snap sits flat against the fabric.