ID means inside diameter. A 1-inch ID rubber grommet has a nominal central passage of 25.4 mm; the required mounting hole is a separate dimension.
Determine whether the passage suits the cable or tube, including connectors and required clearance. The number of cables that fit depends on their actual diameters and arrangement, not the ID label alone.
Check groove dimensions, panel thickness, flange clearance and tolerances. Select the compound for the environment and verify fit. If a seal or cable retention is required, confirm that the selected profile is specified for that function.
Measure the assembled cable envelope
A nominal 1-inch bore is 25.4 mm, but the number of cables it can accommodate depends on their diameters and arrangement. Check the bundle in its intended configuration and include the clearance required by the assembly specification.
Include the installation sequence
A terminated connector may require more space than the cable itself. Confirm whether it must pass through the installed grommet and whether the proposed installation method is feasible. Match panel thickness and mounting-hole dimensions separately; the bore label does not define them.
