When placing an eyelet in your work, having the proper size hole is essential in getting a good setting. How the eyelet hole is made is also important depending on the type of material that you are eyeleting. If your material is rigid and has no stretch, then a hole can be cut. If the material is stretchy, then piercing a hole with a pierce point or bodkin point die will yield a better setting (to go to the Siska Die page, click here).
This article will concern itself with those materials that require a hole to be cut. All eyelets are sized by the Outside Diameter (OD) of the eyelet barrel. The size of the hole should be at least .004 (4 thousands) larger than the OD of the eyelet barrel but no larger than .015 (15 thousands). Using a hole this size can be as large as the Inside Diameter (ID) of the washer.
Grommets have a tapered barrel and their dimensions are usually stated as the hole size after setting. Example: a #2 plain grommet has a hole size after a setting of 3/8th of an inch (.375”). To determine what hole size to cut for a grommet, the ID of the accompanying washer should be used as the hole size.
Example: a #2 washer has an ID of .453”. Making a hole that is larger than needed will result in a weak setting with the possibility that the grommet or eyelet will pull out under pressure.