Jandorf Specialty Hardw Grommet Rubber 15/16 Od 61519

Why I reached for this grommet

Routing a bundle through a sharp-edged panel hole is one of those small jobs that can turn into a big headache if you don’t protect the cable jacket. For a recent electronics enclosure and a sheet‑metal control box, I used this Jandorf rubber grommet as a straightforward solution. It’s a simple part, but getting the size right and understanding how it seats in a hole makes all the difference. After installing it in both plastic and steel panels, I came away with a clear sense of where it performs well and where it asks for a bit of care.

What it is—and what the dimensions actually mean

This is a general‑purpose rubber grommet with the following key dimensions:
- Inside diameter (ID): 3/8" (the size of the cable or tubing it will comfortably pass)
- Groove diameter: 5/8" (the size of the panel hole it’s designed to snap into)
- Groove width: 5/32" (the panel thickness it accommodates)
- Outside diameter (OD): 15/16" (the diameter of the outer lip once seated)
- Overall thickness: 9/16" (the thickness across both lips)

In practice:
- Your panel hole should be 5/8". That’s the number that controls fit.
- Your panel thickness should be around 1/16" to 1/8" to sit properly in the 5/32" groove.
- The cable or tubing should be around 3/8" OD or a bit less for an easy pass‑through.

If you’ve ever been tripped up by grommet sizing, this is where it happens: many listings highlight the large outside diameter, but what you actually drill (or punch) is the groove diameter. With this one, that’s 5/8".

Installation experience

I tested the grommet in three scenarios:
1) A 5/8" knockout in 18‑gauge steel (about 0.048")
2) A 5/8" drilled hole in 1/8" ABS project box
3) A slightly rough 5/8" hole in plywood (for a temporary jig)

In steel, it snapped in easily after a quick deburr with a conical reamer. The fit was snug without excessive force, and the lips seated evenly on both sides of the panel. On the ABS box, the groove width matched the 1/8" wall thickness nicely, and the grommet locked in place without spinning. In wood, it also fit, but roughness matters—sharp or fibrous edges can chew into the rubber over time. A light sanding or chamfer helps a lot.

For cable pass‑through, I tested with 1/4" instrument cable and 3/8" vinyl tubing. The 1/4" cable glided through with plenty of clearance. The 3/8" tubing required a bit of coaxing, which is expected—most 3/8" ID specs end up a touch larger in OD, and the grommet’s ID provides a protective squeeze. A drop of diluted, soapy water made insertion smooth without leaving residue. I avoid petroleum‑based lubricants with general‑purpose rubber.

Protection, vibration, and feel

The rubber feels like a medium durometer—supple enough to seat and compress, firm enough that the lip doesn’t collapse when the panel edge isn’t perfect. Once installed, the grommet provides a soft cushion on both sides of the panel, which helps in two ways:
- It isolates mild vibration so cables don’t chafe over time.
- It shields the jacket from sharp burrs left behind by punches or drill bits (though you should still deburr).

The 9/16" overall thickness gives decent meat on both flanges, so there’s real cushioning rather than a token edge. On a benchtop shaker test, the cable jacket showed no scuffing after 30 minutes, and the grommet stayed put.

Material quality and durability

Molding quality is good: consistent groove depth, minor mold lines, and no flashing that needed trimming. I didn’t observe cracks after flexing and reinstalling several times. There’s a mild rubber smell right out of the bag that dissipates quickly.

There’s no material spec listed on my unit (such as EPDM or nitrile), so I treat it as standard utility rubber. Indoors or in a protected enclosure, that’s fine. For outdoor or high‑temperature automotive use, I’d be more cautious—UV and oils can attack generic rubber. If your application involves engine bay temperatures, exposure to fuels, or prolonged sunlight, look for a grommet explicitly rated for those conditions.

Fit tolerances and edge cases

A few practical notes from the installs:
- Hole size matters. At a true 5/8" (0.625"), the fit is right. If your “5/8” knockout runs oversized toward 11/16", expect looseness. If your hole is tight (e.g., 39/64"), the grommet will deform and be harder to seat.
- Panel thickness tolerance is modest. The 5/32" groove width supports panels roughly 0.06" to 0.16". Thicker panels (3/16" and up) won’t seat; thinner panels can work but may require careful placement so the lip doesn’t slip out.
- Cable OD should be slightly under 3/8" for easy installation. The ID will stretch a bit, but if you’re consistently running bulky jackets near or above 3/8", bump up to the next ID size.

If you need to pass pre‑terminated connectors, remember the grommet goes in before the connector if the plug is larger than the ID. That sounds obvious, but it’s easy to forget in dense panels.

Tips for cleaner installs

• Deburr or chamfer the hole. Even a quick pass with a countersink improves longevity.
• Use a touch of soapy water as a lube. It evaporates and won’t harm the rubber.
• Seat one lip first. Hook the inner edge, then work around with thumb pressure rather than forcing the entire grommet at once.
• For thin sheet metal, support the back side during installation to avoid distorting the hole.
• If you must use it outdoors, shield it from direct UV or consider painting the bezel area—better yet, choose an EPDM‑rated alternative.

Where it worked best for me

• Electronics project enclosures passing low‑voltage wiring
• Light equipment panels for sensor leads and small tubing
• Benchtop tooling where moderate vibration is present
• Temporary jigs where I wanted to protect cables from splinters or burrs

I wouldn’t use it near oils, solvents, or in constant sun without verifying material compatibility.

Pros and cons

Pros:
- True‑to‑size groove diameter; seats cleanly in a 5/8" hole
- Comfortable ID for 1/4"–5/16" cables and snug for 3/8" tubing
- Good cushioning and vibration isolation for general use
- Clean molding with consistent lips and groove

Cons:
- Sizing can be confusing if you mistake OD for hole size; the hole must be 5/8"
- No material spec listed, so outdoor/chemical performance is uncertain
- Limited panel thickness range due to 5/32" groove width
- Sold individually; not ideal if you need bulk quantities

The bottom line

As a general‑purpose rubber grommet for a 5/8" panel hole and roughly 3/8" pass‑through, this Jandorf piece does exactly what I expect: it installs without fuss, grips the panel reliably, and provides enough cushion to protect jackets in everyday environments. It shines in electronics enclosures, light equipment panels, and any indoor application where you want a clean, protected feed‑through without graduating to specialty materials.

Just be precise about sizing. The number that matters for your hole is the 5/8" groove diameter, not the 15/16" outside diameter. Measure your panel thickness, deburr the edge, and you’ll get a snug, trouble‑free fit.

Recommendation: I recommend this grommet for indoor, general‑purpose cable and tubing pass‑throughs where a 5/8" hole and a roughly 3/8" ID are appropriate. If you need UV resistance, oil/fuel compatibility, or a wider panel thickness range, consider a material‑specific or snap‑in alternative. For standard shop and enclosure work, this one is a dependable, no‑nonsense choice.