When our customers contact us to report a problem they’re having setting their Stimpson parts, it seems a reasonable suspicion that there’s something wrong with the parts themselves. As it turns out, the issue is often the tooling being used.

Stimpson Tooling for 405 Machines

That’s why in these instances we almost always ask first what type of tooling the customer has. We do this because there are two major factors at play during the setting process: the eyelet/grommet and the tools. If either one is even slightly off, undesirable results are likely to follow.

Because Stimpson’s inspection process for parts and tooling is quite rigorous, it’s uncommon for us to encounter a complaint that winds up being a result of dimensional irregularity.

The relationship between parts and tooling is critical, if only because a few thousandths of an inch can be the difference between perfect settings and collapsed barrels or split coils (both shown below).


For a brief, illustrated description of the setting process, please read this blog post.

Dimensional differences between Stimpson grommet styles is important as well. For example, a tool designed to set a #2 self-piercing grommet will not reliably set a #2 sheet metal grommet or a #2 rolled rim, despite the fact that they all share “#2” in their names.

Tooling is not likely transferrable between different grommet brands either, which is why we always strongly suggest to our customers that they use tools specifically designed to set their Stimpson parts.

Tooling age is another important consideration. The friction inherent to the setting process will cause the tools to wear and change dimensionally over time, eventually producing results similar to those seen when tools of the incorrect type are used.

We always like to hear from our customers, so please don’t hesitate to drop us a line at customer_service@stimpson.com.