Description
Hexagonal hollow stopper NS 12/21 is a plastic ground-joint stopper intended for reliable sealing of laboratory glassware fitted with standard NS 12/21 taper joints. Manufactured to DIN 12252, the stopper features a hexagonal head for controlled handling and a hollow body that holds the net weight to 0,005 kg. This format is well matched to flasks, condensers, adapters and related NS components used throughout chemical and analytical workflows. Offered as a single-piece pack, the stopper from manufacturer Witeg delivers a dependable closure option for organic chemistry, preparative work and teaching laboratories. The hexagonal profile stays easy to grip when gloves are worn, and the hollow construction reduces mass while preserving seal performance at the ground joint. Gross weight is also 0,005 kg. Ideal for research, quality-control and educational environments that depend on interchangeable NS glassware, it helps keep reaction setups closed and supports sample integrity during short-term storage or transfer steps on the bench.
This article is part of Ground-joint glass stoppers, in Stoppers, caps & closures.
Key features
- Pack size: 1 pc
- Joint size: NS 12/21
- Product type: Hexagonal hollow stopper
- Material: category: Plastic
- Standard: DIN 12252
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Questions about ST-hollow stopper hexagonal ST 12/21
What is this article?
ST-hollow stopper hexagonal ST 12/21 is the article on this page. Luminix Health distributes Witeg for laboratory use. It sits in Ground-joint glass stoppers, inside Stoppers, caps & closures, in Labware.
A ground-glass stopper matches a ground neck of a stated joint size. A 14/23 stopper does not seal a 29/32 neck. The stopper is part of the flask's seal, and a chip on the grind is a leak.
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 Ground-joint glass stoppers. The catalogue is Labware.
Shelves beside this one are Screw caps & closures, Rubber & silicone 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.