Overview
A fluid reservoir cap is the screw cover that closes a round port on a tank, a reservoir or a filler neck. It is molded as one part: a fluted skirt, a flat face, an internal thread up the wall, and a ring that stands inside the floor.
The skirt carries flutes around its full height, so a fluid reservoir cap turns with a bare hand or a glove. The thread takes the port neck, and a short lead-in at the mouth lets the cap start square instead of crossing the thread. The inner ring stands proud of the floor, so the port lip bears on the ring rather than on the skirt edge.
Key Features & Benefits
- Fluted skirt: grip over the full height
- Internal thread: cut to your port neck
- Lead-in at the mouth: the cap starts square
- Inner ring: the band the lip bears on
- Flat top face: room for a mark or label
- One piece: no insert, no loose liner
A cap comes off the tool with the thread started at the same point each shot, so a fluid reservoir cap turns down to the same height on the neck.
Customization Options
- Diameter and height
- Thread: pitch, start and length
- Skirt: flute count and profile
- Inner ring: diameter and height
- Top face: flat, recessed or with a mark
- Material: PP, HDPE or nylon
- Color: black, gray or a matched shade
A matching neck can be molded to the same thread, so a fluid reservoir cap and its port come as one set. A tether strap can be added at the skirt where the cap stays with the tank.
Quality & Delivery
Tooling for a fluid reservoir cap is cut in our own mold shop, and the first article is gauged against your 3D file, thread start and ring height included, before the run is released.
Mold faces are polished to the sheen your 3D file calls for, the gate is trimmed flush, and the thread comes off clean, so every fluid reservoir cap runs down the neck without a tight spot. Lead time is quoted with the unit price and held to the date, and each batch is gauged before packing.
We mold every fluid reservoir cap to your 3D file, so the thread, the ring and the flutes follow the model. Send the 3D file for a quotation with the tool cost and the unit price.
Related Capabilities
A cover on a round part sits beside this fluid reservoir cap. Our dome cap presses onto a shaft, and the snap-in end cap closes a panel hole with no thread at all.
Where a cap has to match an existing port, the round cap with a raised bar shows the same skirt and face, and the threaded adapter is the neck end of the joint on its own.
Molding runs in house on our mold making floor, with injection molding for the cap. Our automotive plastic parts page groups vehicle work, our capabilities page lists the cells and our works page shows past jobs.
