Five eighths of an inch equals 15.875 mm. When a grommet is described as 5/8 inch, confirm which dimension the listing means. A bore dimension alone does not specify the installation hole.
Avoid an assumed size pairing
A 5/8-inch bore does not universally require a 7/8-inch panel hole. For a 7/8-inch hole, select a part explicitly specified for that mounting-hole size and the panel thickness, then check its bore and cable clearance.
Check the complete part
Review flange overlap, overall thickness and the installation method. Select the material for the operating environment. An open grommet helps protect a cable jacket from the edge; it does not automatically establish dust sealing, water sealing or electrical safety.
Keep the drawing and part reference with the purchase requirements so that dimensions are not inferred from the article title.
Use our size finder to compare listed dimensions, then check the selected part drawing and material specification.
