Description
Screw caps N-18 with hole are laboratory screw closures designed for secure sealing of compatible bottles and vessels in analytical and preparative workflows. Manufactured from black polypropylene (PP), these caps combine chemical resistance with a robust, lightweight construction suited to routine laboratory handling. Each cap features a central hole, allowing use with septa or other piercing accessories where sampling, reagent addition, or gas exchange is required without fully removing the closure. Cap size N-18 ensures a precise fit on matching threaded necks, supporting reliable sealing performance during storage, transport, and day-to-day use. Supplied in practical packs of 100 pieces from manufacturer Witeg, the closures are convenient for stocking high-throughput labs, quality-control environments, and general chemistry benches. Their black PP body offers good mechanical stability and is appropriate for a wide range of aqueous and organic media typically encountered in laboratory practice. Ideal as replacement or bulk screw caps for N-18 systems, they support consistent, repeatable closure of sample bottles and reagent containers.
This article is part of Screw caps & closures, in Stoppers, caps & closures.
Key features
- Pack size: 100 pc(s)
- Product type: Screw caps with hole
- Cap size: N-18
- Material: Black polypropylene (PP)
- Design: Central hole for septum use
- Origin: Germany
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Questions about Screw caps N-18 with hole
What is this article?
Screw caps N-18 with hole is the article on this page. Luminix Health distributes Witeg for laboratory use. It sits in Screw caps & closures, inside Stoppers, caps & closures, in Labware.
A screw cap has a thread and a liner. The thread has to match the bottle. The liner has to survive the liquid: a pulp liner fails in a solvent that a PTFE-faced liner ignores. The colour of the cap is not the specification.
A closure is the part that decides whether a bottle stays shut and whether the contents attack the seal. A ground-glass stopper matches a ground neck. A screw cap needs the right thread and a liner that survives the liquid. Rubber and silicone stoppers push into a mouth. The liner, not the colour of the cap, is the chemical choice. The vessels they close are indexed under ISO laboratory glassware.
Which category should I open next?
The category is Stoppers, caps & closures. The sub-category is Screw caps & closures. The catalogue is Labware.
Shelves beside this one are Rubber & silicone stoppers, Ground-joint glass stoppers, Lids & seals and Closures (other).
What should I check before I order?
When this page shows a safety data sheet, use that manufacturer file. Hazard text does not belong in the sales description. For a pack size, a grade or a certificate that is not on the page, send a quote request or contact the team.
How does ordering and shipping work?
Luminix Health distributes this article from the heart of Europe. Articles in stock ship within 2–5 business days. Standard delivery is free from €250 excl. VAT. Cold-chain goods and dangerous goods under ADR are never included in that free delivery. The terms are in the Shipping Policy. The full brand index is on shop by brand. Who we are is on about us.
Which other categories should I open?
The seven catalogues are Labware, Lab chemicals, Lab instruments, Lab consumables, Chromatography equipment, Lab safety equipment and Life Science & Microbiology.