The fit comparison
Compare the published fit limits
The nominal size describes the insert. Confirm the body diameter and clear cap opening for the exact variant.
Scroll across the table for every fit check.
| Model | Nominal size | Listed height | Check first |
|---|---|---|---|
| Black metal desk grommet, 60 mm For a nominal 60 mm opening | 60 mm nominal | 15 mm listed height | Measure the body and usable cable slot. |
| Black metal desk grommet, 80 mm For a nominal 80 mm opening | 80 mm nominal | 15 mm listed height | Check plug clearance and cap access. |
Measure the hole, body and cap separately
Remove the existing loose insert if the maker permits it. Measure the inside diameter across the bare hole in two directions. A worn or unfinished hole can be slightly oval. Compare the hole with the outside of the replacement body, then measure the lip that sits on top. The lip needs a flat landing area and space around the edge.
The cap’s usable opening is another measurement. A 60 mm nominal insert can leave a much smaller slot once its lid is fitted. Pass the widest plug through the proposed opening with the cap removed, then check the bundle with the cap seated. Include right-angle connectors, strain relief and any lead you will remove often.
Use the 60 mm insert for a matching hole
The selected black metal outlet is listed as a single 60 mm insert, 15 mm high. Confirm the body diameter and any installation tolerance with the seller. Measure the depth available beneath the lip, especially when a drawer or steel rail passes close to the hole.
For a nominal 60 mm opening
Black metal desk grommet, 60 mm
A round outlet insert finishes the edge of a compatible existing desk cable hole.
Confirm the fitted body diameter and measure the usable opening with the cap in place.
- 60 mm selected size
- 15 mm listed height
- Single black insert
A plug can fit through the hole and still run into a drawer or rail below it. Check the connector at the angle it needs to pass. Plan where the first cable bend will sit and keep it clear of runners and moving parts.
Use the 80 mm insert where the worktop already allows it
The black 80 mm version is also listed at 15 mm high. Its wider nominal size may give more room to route plugs through a suitable existing hole. Confirm the cap opening and fitted body on the exact insert before choosing it.
For a nominal 80 mm opening
Black metal desk grommet, 80 mm
The larger size is designed for a wider matching hole with a removable cap.
Check the widest plug and the opening with the cap fitted. Confirm there is clear space underneath.
- 80 mm selected size
- 15 mm listed height
- Single black insert
For example, if the plug is 33 mm wide and the slot is 20 mm, it needs to go through with the cap removed or use another approved path. Plan how to unplug it later. Keep the cap easy to remove and avoid pinching or forcing any lead.
Keep cable access clear below the desk
Check the cable path from the hole to the sockets. On a sit–stand desk, test the intended height range and keep leads clear of the frame. Use the desk maker’s guidance before drilling or enlarging a hole. A cable insert finishes an opening for leads. A through-desk monitor-arm fixing has its own requirements for material, hole size and lower support.
If leads cross under the hole, test the order in which you feed them through. A bulky connector may need the space before the smaller leads fill it. Check that the cap closes without compressing insulation and that each lead can move enough for you to unplug it.
Common questions
Is the nominal size the same as the cap opening?
The nominal size refers to the insert size. Measure or confirm the body and usable cap opening separately.
How do I measure an existing desk hole?
Measure the inside diameter across the bare opening in two directions and check the depth beneath the lip.
Can I pass a UK plug through it?
Measure the actual plug at its widest point and confirm the available path with the cap off.
Can a cable insert support a monitor arm?
Use a fitting approved by the desk and arm makers. The cable insert has a different purpose and does not support the mount.
What if the cable rubs underneath?
Check the bend and clearance below the hole. Reroute the lead away from sharp edges and moving parts.
Sources and selection
Sources and Amazon UK listings checked in November 2026. Dimensions and fit checks use published specifications. Published specifications for Black metal desk grommet, 60 mm and Black metal desk grommet, 80 mm come from the selected Amazon UK listings.