Description
Screw caps N-18 closed with seal are closed laboratory screw closures manufactured from black polypropylene and equipped with a white styrene-butadiene gasket. The full-cap construction delivers a continuous sealing face for vessels with an N-18 neck finish, supporting dependable containment for samples, reagents, and process solutions during storage and handling. Packs of 100 pieces provide a convenient stock unit for busy laboratories that need consistent screw-thread closures for bottles and related labware. These N-18 caps from manufacturer Witeg pair polypropylene durability and chemical resistance with an integrated white styrene-butadiene seal intended for reliable everyday sealing performance. The closed design is preferred when an open-top septum is not required, helping limit evaporation and protect contents under normal laboratory conditions. A pack net weight of 0,25 kg keeps the assortment easy to store and issue at the bench. Suitable for analytical, preparative, and general laboratory workflows, the caps match corresponding N-18 screw-thread glass and plastic containers used throughout sample preparation and storage chains.
This article is part of Screw caps & closures, in Stoppers, caps & closures.
Key features
- Pack size: 100 pc(s)
- Cap type: Closed screw cap with seal
- Cap size: N-18
- Material: Black polypropylene (PP)
- Seal: White styrene-butadiene gasket
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Questions about Screw caps N-18 closed with seal
What is this article?
Screw caps N-18 closed with seal 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.