Test Tubes Closure Cap
Product Code : EL-TT-10140
Lab Glassware Manufacturer supplies the Test Tubes Closure Cap from its manufacturing facility in Ambala, Haryana, to schools, colleges and laboratories across India and export buyers in Romania, Bulgaria and Moldova and other markets across Southeast Europe.
Quick answer: This is a closure cap for sealing the open end of a test tube, sized to fit five common tube diameters — 12 mm, 15 mm, 18 mm, 20 mm and 25 mm — used to protect samples from contamination, spillage and evaporation during storage, transport or between steps in a procedure.
Matching Cap Size to Tube Diameter
A closure cap only seals effectively when its internal size matches the outer diameter of the test tube it is fitted to; too loose and the seal fails to protect against contamination or spillage, too tight and the cap can be difficult to remove or may crack the tube rim. Covering five sizes from 12 mm up to 25 mm lets a single supplier match caps to most of the common tube diameters used in a school, college or general laboratory setting, from slim sample tubes through to standard test tubes. Keeping a stock of the correct size on hand also avoids the common workaround of stretching a cap meant for a different diameter, which rarely gives a reliable seal.
Frequently Asked Questions
What tube sizes does this closure cap fit?
It is available in five sizes matched to tube diameters of 12mm, 15mm, 18mm, 20mm and 25mm, covering most standard test tube diameters used in school, college and general laboratory settings.
How do I know which cap size I need?
Measure the outer diameter of the test tube's open end and match it to the closest available cap size; an accurate match is what gives a reliable seal against spillage, contamination and evaporation.
What happens if the cap size doesn't match the tube?
A cap that is too loose will not seal reliably and can come off during handling, while one that is too tight can be difficult to remove or risk cracking the tube rim. Matching the exact size avoids both problems.
Can this be supplied for bulk, tender or export orders?
Yes. It is supplied in bulk to schools, colleges and laboratories in India and is exported to distributor and institutional buyers, including recent enquiries from Southeast European markets such as Romania, Bulgaria and Moldova. Share required sizes, quantity and destination country through Contact Us or the Tenders page for a quotation.
Related Products
Explore other Test Tube accessories: Test Tube With Interchangeable Stopper and Flat Bottom Test Tube, or see the full Test Tube range.
Request a Quote
Ready to order the Test Tubes Closure Cap for your laboratory, institution or export order? Contact Us for a quotation, or visit the Tenders page for bulk and institutional procurement.
Last updated: September 2026.