Fastener Selection: What Barrel Length Do I Need for My Snap?
X-HT-300033
The barrel is the part of the fastener that gets riveted to the piece’s mating component. In other words, it’s the straight stem-like part that comes out of the button top. If your barrel is too short, it won’t be able to rivet through all of your fabric layers. But if the barrel is too long, it will get in the way of your snap functioning.
The most common barrel sizes for buttons are 11/64-inch and 3/16-inch. Here’s a helpful chart for quick reference that breaks down which button barrel length is best for the layers of canvas in your project. The numbers for "layers of canvas" are based on layers of marine grade material.
| Layers of Canvas | Material Thickness | Barrel Length |
| 2-6 | 0.046"-0.136" (1.16mm-3.46mm) | 11/64" and 3/16" |
| 6-9 | 0.136"-0.201" (3.46mm-5.12mm) | 1/4" |
| 6-9 | 0.201"-0.312" (5.12mm-7.91mm) | 5/16" |
The eyelet part of a snap fastener also has a barrel, but its sizing is a little different. Since the eyelet rivets to a larger piece of hardware, the stud, the 1/4-inch barrel for eyelets is standard for most projects. However, if your assembly is very thick — over 7 or 8 layers — then you’ll want to move up to the 5/16-inch barrel.
We hope this blog answered your questions about different snap fastener barrel lengths and how to choose the right size for your project. If you have any additional questions, feel free to contact us or post your question in the comments section below.
