Description
Solid replacement plug NS 21,5 with a 6,3 mm bore and screw fitting is a robust ground-joint spare for laboratory stopcocks manufactured according to DIN 12541. This massiv NS-Ersatzküken incorporates a Verschraubung (screw connection) that secures the plug in the stopcock body, combining reliable sealing with positive retention under routine laboratory use. The larger 6,3 mm bore supports higher flow rates of liquids or gases once the plug is rotated open, making the component suitable for apparatus handling bulk reagents, vacuum lines or process streams. The precision-ground NS 21,5 taper ensures compatibility with matching sockets on larger stopcock assemblies. Supplied as one piece with a net weight of 0,044 kg, it serves as a direct replacement part for worn or broken inserts. The plug is available from manufacturer Witeg and follows established dimensional conventions for interchangeable laboratory glass joints. Ideal for research, production-support and teaching laboratories, it helps extend the service life of stopcock-equipped glassware. Explicit identification of joint size, bore and screw fitting simplifies selection and stock control.
This article is part of Ground-joint glass stoppers, in Stoppers, caps & closures.
Key features
- Pack size: 1 pc
- Type: Solid NS replacement plug with screw fitting
- Joint size: NS 21,5
- Bore diameter: 6,3 mm
- Standard: DIN 12541
- Construction: Solid (massiv) with screw connection
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Questions about ST-seperate plug ST 21,5 solid
What is this article?
ST-seperate plug ST 21,5 solid 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.