Description
Closed screw caps N-18 are laboratory closures for bottles and vessels that accept the N-18 screw-thread standard. These caps are closed at the top and come without a sealing insert or liner, making them appropriate where a solid polypropylene closure is preferred. Produced from black PP, they provide the handling ease and chemical resistance typical of polypropylene laboratory plastics. Each pack holds 100 pieces, a convenient quantity for continuous laboratory use and stock control. The pack net weight is 0,13 kg, reflecting the lightweight moulded design. Cap size N-18 supports pairing with matching glass or plastic containers common in analytical chemistry, quality control, and research environments. These closed screw caps from manufacturer Witeg suit sample handling, reagent storage, and general laboratory organisation. Their solid, non-perforated form sets them apart from septum and open-top variants and offers a straightforward mechanical seal on compatible vessels. The black finish ensures a consistent look across the pack and helps rapid visual identification beside other closure types on the bench.
This article is part of Screw caps & closures, in Stoppers, caps & closures.
Key features
- Pack size: 100 pc(s)
- Cap size: N-18
- Design: Closed, without seal
- Material: Black polypropylene (PP)
- Colour: Black
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Questions about Screw caps N-18 closed
What is this article?
Screw caps N-18 closed 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.