Grommet or Grommet Edging for 3" Diameter Irregular Hole in Firewall


I’m doing engine swap for a personal project vehicle. I needed to punch a 3" hole through the engine bay to the trunk where the engine computer is located to route a new main wiring harness.

The sheetmetal is 1mm (approx 0.040") and, despite my best efforts, it seems impossible to deburr it to a point where it is not sharp. I’m afraid that it will cut the harness.

The hole is approximately 3". Is there a grommet that would fit this size - something with around a 1.5" ID? If not, can someone recommend a piece of grommet-edging that would work? Hopefully something not super big. A foot would probably do it.

Attaching a photo to show what the hole looks like.

Welcome to the Digikey tech forum. Take a look at Digikey part 298-19089-ND as a possible option. We also have some sleeve options that you could maybe slide over the wires for extra protection.

Hi Steve,

Many thanks. That part looks like it would work well. I appreciate the support.


Just to follow up. I ordered 298-19089-ND and it worked perfectly. Once again I appreciate the help in finding me a good part that fits.