Description
Closed screw caps N-18 are laboratory screw closures manufactured from black polypropylene (PP) and equipped with a butyl-PTFE laminated gasket. Matched to the N-18 cap size, they provide a closed seal for bottles and vials used in sample preparation, intermediate storage, and standard laboratory procedures. The black PP construction gives a robust, easy-to-handle shell, while the butyl-PTFE laminated lining helps maintain contact along the sealing surface of the vessel neck. Each pack contains 100 pieces, supporting batch setup of multiple containers or efficient replenishment of common lab stocks. These N-18 closed screw caps from manufacturer Witeg fit workflows that call for a solid, non-open-top closure rather than a septum-style lid. Net weight of the pack is 0,2 kg. They are appropriate for research, quality-control, and teaching environments where N-18 black PP caps with butyl-PTFE seals are specified for everyday vessel closure.
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
- Material: Black polypropylene (PP)
- Seal: Butyl-PTFE laminated gasket
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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.