Size 20 Extra Long

B24 Light Gray

Size Guide
Choosing the Right Plastic Snaps

Which size works best for you will depend on a number of variables, such as the fabric you are using, its density and compression levels, how hard you are able to press, and your own personal preference.  For these reasons, we are unable to provide specific size recommendations for every scenario. 

The 3 most commonly used sizes, in the order of popularity, are:

  1. Size 20 regular length
  2. Size 20 extra long (for thicker material)
  3. Size 16 regular length (for thinner material)

Not sure? Try the variety size sampler kit.

KAM Snap Size Comparison Chart


Size 20 (12.4mm or 1/2" cap diameter)

  • Size 20 Regular Length (5.6mm prong) is commonly used for general applications including baby diapers, regular clothing, and household projects.   This is the most popular size of plastic snaps and is a good size to start with for most projects. Days for Girls menstrual pads are made with this size.
  • Size 20 Extra Long (6.2mm prong) is necessary for very thick material like double layers of marine vinyl for key fobs, medium weight leather, and chinese prefold diapers. 
  • Size 20 Extra Short (4.6mm prong) is good for thinner material where you still want a good, strong grip such as baby diapers made with just 1-2 layers of PUL.

Size 16 (10.7mm cap diameter)

  • Size 16 Standard Length (4.6mm prong) is most commonly used for thin, stretchy, or delicate material such as knits for baby/toddler clothing, doll clothing, and multiple layers of grosgrain ribbon.  Size 16 sockets and studs have a gentler grip compared to size 20 sockets and studs so are a bit easier to open and close, but the grip is still very secure so any fabric prone to tearing should be reinforced with more durable material at the point where the snaps are installed.
  • Size 16 Long-Prong is available in lengths ranging from 5.2mm - 7.2mm long for thicker material.

Size 14 (9.7mm cap diameter)

  • Size 14 Standard Length (3.5mm prong) is extremely short and should only be used on very thin material, usually single layers. 
  • Size 14 Long-Prong (5.0mm prong) for thicker material.

Size 22 (14.1mm cap diameter, 7.0mm prong)

  • A larger snap which can be used in similar situations as size 20 long-prong.

Size 24 (14.8mm cap diameter, 7.5mm prong)

  • Our largest, strongest snap which should only be used in very heavy duty applications with thicker material such as canvas tote bags, nylon webbing, dense leather and thick jackets. Because the grip is so strong, it can tear through more commonly used fabric.

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