Description
DURAN® hexagonal hollow stopper, flat, DG-ground NS 12/21 is a hollow glass stopper for closing laboratory vessels fitted with standard ground joints. Manufactured from borosilicate glass 3.3, it is intended for use with volumetric flasks, mixing cylinders, ground-joint flasks and similar apparatus. The stopper belongs to the DURAN® hexagonal hollow stopper range, which is supplied in two standard variants—pointed and flat—with joint sizes matching the DURAN® conical ground joint series. DG denotes diamond-ground finishing that produces a precise sealing surface. The flat top and hexagonal outer profile allow secure gripping and controlled tightening by hand, while the hollow construction keeps mass low at a net weight of 0,005 kg. This single-piece stopper from manufacturer Duran/DWK Life Sciences provides an effective closure for vessels equipped with NS 12/21 joints. Its diamond-ground contact face supports consistent sealing during repeated opening and closing in analytical, preparative and teaching laboratories where a lightweight yet robust standard-joint stopper is required for routine glassware work.
This article is part of Ground-joint glass stoppers, in Stoppers, caps & closures.
Key features
- Pack size: 1 pc
- Storage temperature: Standard
- Material: Borosilicate glass 3.3
- Joint size: NS 12/21
- Finish: DG (diamond ground)
- EAN: 4032051046139
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Questions about DURAN® Hexagonal Stopper flat, diamond-ground
What is this article?
DURAN® Hexagonal Stopper flat, diamond-ground is the article on this page. Luminix Health distributes DWK Life Sciences 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.