Four-part rivet snaps, known as snap fasteners, join all kinds of materials easily and firmly, from thinner fabrics to heavier leathers.
Types of snap fasteners: WUK and AM
You will most often come across two types:
- WUK (Anorak)
- AM (Auto Moto, sometimes also Sport & Camping).
At first glance they look alike, but their properties and uses differ.
WUK snaps (Anorak)
- They snap shut smoothly and open even more easily.
- A good choice for fabric and for places where the snap gets used a lot: jackets, vests, backpacks.
- The closure is reliable, but it takes a bit of force.
AM snaps (Auto Moto / Sport & Camping)
- For when you need something to stay shut as if it were nailed down.
- Opening them? Let’s just say you will have to put some muscle into it.
- They suit bags, gear, tarps and technical fabrics, where security matters most.
In short:
For style and everyday use, go with WUK.
For durability and strength, go with AM.
The parts of a snap fastener
Every snap consists of four separate parts: two upper and two lower.
Put the two matching halves together and you have a working pair.
Upper parts
- Cap: the nice-looking visible part (on top).
- Socket: hidden under the cap, it holds the spring that makes the “click”.
Lower parts
- Stud: the lower part the socket snaps onto.
- Post: the bottom piece that holds the whole joint together.
Important: do not mix parts from different snaps. With some types (such as AM) it is technically possible, but the joint may not be reliable. Always use the parts that belong together.
Snap fastener finishes and sizes
Snaps are made of steel (AM also of stainless steel) and then finished. That means you can choose the size (WUK 8, 10 or 12 mm, AM 12.5 or 15 mm), the look and the durability. We sell snaps by the hundred, with a minimum order of 100 pcs.
The finishes vary by type and size: we have WUK in nickel-plated and black nickel in all sizes, and in antique brass and brass-plated only in the 12 mm size. We have AM in nickel, antique brass, brass-plated and antique copper, and stainless steel in the 15 mm size.
Also choose the snap by the thickness of your material: WUK 8 mm up to 2.3 mm, WUK 10 mm up to 2.5 mm, WUK 12 mm up to 3.3 mm, AM 12.5 mm up to 3 mm, AM 15 mm up to 4 mm. For thicker material (3–6 mm), use the AM 15 mm with a longer post (marked -L).
Each finish has a slightly different character:
Nickel
A classic silver look that goes with almost anything.
Antique brass
Elegant patina that suits a vintage style.
Brass-plated (gold tone)
Bold and decorative.
Antique copper
A dark, almost black shade.
Black nickel
A modern, dark matte surface.
Stainless steel
The highest resistance to moisture and corrosion.
Where to use them? Almost anywhere
Snap fasteners have a wide range of uses:
- in clothing (jackets, coats, vests),
- in leather goods (cases, flaps, pockets),
- in shoemaking (slippers, boots, accessories),
- and even on dog clothing or pet carriers.
The only place to be careful is thin fabric: without interfacing, the snap could tear out.
How to set snap fasteners correctly
1. Prepare the hole
Use a hole punch that matches the post diameter of the snap: usually 2–3 mm for WUK and 3–4 mm for AM. You will find the exact size in the specifications of each snap. The hole should be clean, with no ragged edges.
With soft materials (fabric, faux leather), we recommend ironing on interfacing so the snap does not tear out over time.
2. Line up the parts
Upper half: push the cap through the hole from the grain side and add the socket from the flesh side. Lower half: push the post through from one side and cover it with the stud from the other. Do not mix parts from different sets.
3. Use the right tool
Either:
- a hand snap setter (for example a plastic one, or a metal one with an anvil),
- or a hand press with a die (the most comfortable and most accurate option).
Whatever you use, apply even pressure.
➡️ Go for several lighter blows rather than one big one. A snap is not an anvil: it is made of thin sheet metal.
Practical tips
- Don’t overdo the force. The snap needs to be pressed together, not destroyed.
- Do a test run before the final setting. A leather scrap works well.
- The caps are shiny, so work on a clean surface to avoid scratching them.
- Snaps hold things closed, but they are not made to carry a pulling load. Do not use them to attach a leash or a buckle; they are not built for that.
How to set a snap fastener step by step
What you need:
- A complete snap fastener (4 parts)
- A hole punch or rotary punch pliers
- A setter for WUK 8, 10 and 12 mm snaps or a setter for AM 12.5 and 15 mm snaps (each snap size needs a setter of its own size)
- A hammer or a mallet
In production, many workshops also use presses with dies: they apply even pressure and prevent mistakes. How to operate a press is explained in the article Riveting with a Hand Press, and you can read about choosing a hole punch in our comparison of hole punching tools. The videos below show what the process looks like.
Setting snaps with a press
Setting an AM snap
Setting a WUK snap
Setting the upper half of the snap
- Place the round cap into the anvil.
- Lay the material on top, grain side down.
- Add the second part of the snap.
- Insert the setter into the opening and make sure it sits properly.
- Join the parts with a few blows and you are done.
Setting the lower half of the snap
The principle is the same; you just swap the order of the parts:
- Place the post into the anvil.
- Lay the material on top, flesh side down.
- Add the matching part (the stud).
- Position the setter and join the parts with a few blows.
The whole process on video
Setting an AM snap
Setting a WUK snap
Common mistakes (and how to avoid them)
Material too soft → risk of tearing
Hole too big → the snap will not hold
Off-center blow → the snap ends up crooked or will not close
Blow too hard → the snap gets dented and is ruined
When is it time to replace a snap?
Snaps last a long time, but like any mechanical joint, they can wear out eventually. In WUK snaps the spring is made of thin wire, so after years it can bend out of shape, break or stop holding. AM snaps have a sturdier spring design, so you will rarely run into this problem with them.
The most common types of damage:
- Worn-out spring: mainly in WUK snaps, it stops holding over time.
- Poorly set snap: it wobbles and can fall out.
- Deformed part: often caused by too hard a blow.
What can you do?
Unfortunately, a damaged snap cannot be repaired. The simplest solution is to snip it off with cutting pliers and replace it with a new one. If a snap gets damaged while you are setting it, replace it right away; otherwise it would loosen over time anyway and stop working properly.
Summary
Snap fasteners are small but handy. When you know what you are doing, they will hold for years. Choose the right type, size and finish, use the right tools, and click: you have a joint that works and looks good too.
All that is left is to pick the size, the finish and the setter.