Description
Reducing stopper KNS 40/38 → HNS 24/29 is a short transition piece in stopper form that connects laboratory glassware fitted with different standard ground joints. It combines a cone joint NS 40/38 with a socket joint NS 24/29 and is manufactured in accordance with DIN 12257, ensuring dimensional compatibility with common European laboratory glass systems. This compact reducing stopper allows a straightforward reduction from the larger NS 40/38 size to the smaller NS 24/29 size, making it useful in distillation trains, reaction apparatus and multi-neck flask assemblies where space is limited. Produced by manufacturer Witeg, the piece offers a practical stopper-style geometry that seats securely and helps minimise unused volume between connected components. The unit is supplied as one piece and has a net weight of 0,104 kg. Typical applications include organic synthesis setups, solvent recovery systems and general laboratory glassware configurations that rely on interchangeable NS joints. By bridging two widely used joint sizes in a single short adapter, the reducing stopper simplifies apparatus design and supports reliable, repeatable connections in daily laboratory practice.
This article is part of Ground-joint glass stoppers, in Stoppers, caps & closures.
Key features
- Pack size: 1 pc
- Product type: Reducing stopper / short transition piece
- Cone joint: NS 40/38
- Socket joint: NS 24/29
- Standard: DIN 12257
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Questions about Short adapter CST 40/38 -> SST 24/29
What is this article?
Short adapter CST 40/38 -> SST 24/29 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.