Selecting a grommet by hole size starts with identifying which hole is being measured. The panel cutout and the bore through the grommet are different dimensions and both affect selection.
Record the dimensions
Measure the panel cutout, panel thickness and cable or tube outside diameter. Use explicit units for every value. Compare them with a specific part drawing rather than an unverified list of nominal sizes.
Review available profiles
A part with a suitable bore may still have the wrong groove width or mounting-hole requirement. Check flange clearance and overall thickness as well. Do not resize the panel or force the grommet to fit without reviewing the intended assembly.
If no listed part matches, provide a drawing or existing sample for manufacturability review. Include material requirements, tolerances and quantity so that a custom option can be assessed.
Use our size finder to compare listed dimensions, then check the selected part drawing and material specification.
