A hand press sets each snap in 2 presses: one for the socket half and one for the stud half. The die decides which snap you can set, so match the die to the snap type and size before you start. This guide covers the 3 snap types our die sets take: four-part metal snaps (10mm to 15mm), plastic resin snaps (T3, T5, T8) and open ring prong snaps (9mm).
What You Need
- A hand press with a screw-in top die, like our cast iron hand press or the lighter aluminium hand press.
- A die set that matches your snaps (see the table below).
- Snaps of the same type and size as the die.
- A white or black tailor's chalk pencil and a tape measure to mark and space the snaps.
- A small hole punch or an awl for metal and plastic snaps.
- A scrap of your fabric, folded to the same number of layers as the garment, for a test snap.
Which Die Sets Which Snap
| Snap type | Our die sets | Dies in the set | Hole | Good for |
|---|---|---|---|---|
| Four-part metal snaps: cap, socket, stud and post | 10mm, 12.5mm, 15mm Type 408, 15mm Type 7050 | 4 | Punch a small hole | Jackets, coats, bags, canvas, faux leather |
| Plastic resin snaps: 2 caps, a socket and a stud | T3 (size 16), T5 (size 20), T8 (size 22) | 4 | Awl hole in dense fabric | Baby clothes, cloth diapers, bibs, ponchos |
| Open ring prong snaps: 2 prong rings, a socket and a stud | 9mm | 2 | No hole | Jersey, rib knit, baby bodysuits, T-shirts |
A die sets only the snap size it was made for. A 12.5mm snap won't close in a 15mm die, and a T5 snap won't seat in a T8 die.
Which Half Goes Where
The socket half goes on the overlapping layer, the one on top when the garment is closed. The stud half goes on the layer underneath. Mark every snap point with chalk before you set the first one, and measure the spacing so the snaps line up.
Set Up the Press
- Screw the top die into the press head by hand until it stops.
- Drop the matching bottom die into the hole in the press base.
- Lower the lever slowly with no snap in place and check that the top die meets the bottom die in the center.
- Set one test snap on your folded scrap. Open and close it a few times before you move to the garment.
Each 4-piece set has 2 pairs of dies: one pair for the socket half and one for the stud half. Swap both dies when you switch halves.
How to Set Four-Part Metal Snaps
- Punch a hole at the mark, just big enough for the tube on the back of the cap.
- Put the cap face down in the cup of the first bottom die, tube up. Lay the overlapping layer over it, right side down, so the tube comes through.
- Seat the socket in the matching top die. Lower the lever and press once, firmly. The tube rolls over inside the socket.
- Close the garment, mark the stud point under the socket and punch the second hole.
- Swap to the second pair of dies. Put the post in the bottom die with the tube up and lay the under layer over it, right side up.
- Seat the stud in the top die and press. Snap the two halves together to check the hold.
How to Set Plastic Snaps (T3, T5, T8)
- On dense fabric, open a small hole at the mark with an awl.
- Put a cap in the first bottom die, prong up. Lay the overlapping layer over it, right side down, and push the prong through.
- Seat the socket in the matching top die and press once. The prong flattens inside the socket.
- Swap to the second pair of dies. Put the second cap in the bottom die with the prong up and lay the under layer over it, right side up.
- Seat the stud in the top die and press.
- If a snap spins, the prong didn't flatten all the way: put it back in the die and press once more.
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How to Set 9mm Prong Snaps
- Put a prong ring in the bottom die, prongs up, with the center pin through the ring.
- Lay the overlapping layer over it, right side down, at your mark. No hole is needed.
- Seat the socket in the top die and press. The prongs go through the fabric and fold over the socket rim.
- For the stud half, put the second prong ring in the bottom die and lay the under layer over it, right side up.
- Seat the stud in the top die and press. The same 2 dies set both halves.
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Tips for Snaps That Hold
- Back thin or stretchy fabric with a small square of fusible interfacing on the wrong side, so the snap can't tear out.
- Press once, firmly. Several light presses can dent a metal cap or crack a plastic one.
- Keep snaps off seam bumps and thick hem corners: the die needs a flat, even stack of layers.
- Set a test snap each time you change the fabric or the number of layers.
Fixing Common Problems
| Problem | Likely cause | Fix |
|---|---|---|
| Snap spins or pulls out | Hole too big or fabric too thin | Punch a smaller hole and add interfacing |
| Snap won't close | Tube or prong not fully rolled, or halves of different sizes | Press once more and check that both halves are the same size |
| Cap dented or scratched | Die doesn't match the snap size | Use the die made for that snap size |
| Prongs bent sideways | Fabric too thick for prong snaps | Use a metal or plastic snap on thick layers |
Questions About Setting Snaps
Can one die set do metal and plastic snaps?
No. Metal snaps need a metal snap die, and plastic snaps a T3, T5 or T8 die of the same size.
Do I need to punch a hole for snaps?
For four-part metal snaps, yes. For plastic snaps, an awl hole helps on dense fabric. Prong snaps need no hole.
Which snap size is best for a jacket?
12.5mm or 15mm metal snaps for jackets and coats, 10mm for kids' clothes and small flaps.
Will these dies fit my press?
They fit hand presses where the top die screws into the press head and the bottom die sits in a hole in the base, like our cast iron and aluminium presses.
See all our fastener and setting tools.
