- Physics Lab Equipment
- Chemistry Lab Equipment
- Biology Lab Equipment
- Anatomical Lab Equipment
- Learning
- Educational Lab Equipment
- Magnets
- Agriculture
- Astronomy
- Earth Science
- Geography Lab Equipment
- Safety Lab Coat
- Laboratory
- Meteorological
- Electricity & Magnetism
- Heat
- School Lab Equipment
- Lab Glassware
- Science Lab Equipment
- Tvet Lab Equipment
- Robotics Kits Supplier and Manufacturer for Schools India
- Math Lab Equipment Manufacturers and Exporters in Ambala
- STEM Kits Manufacturers and Supplier India
- Engineering Lab Equipment
- Hospital Lab Equipment
- Water, Sanitation & Hygiene Supplies
- Cold Chain, Solar & Communication Equipment
- Nutrition
Rubber Cork
Rubber Cork (Product Code: SLE/CH/47) is a tapered stopper in soft, solid red rubber for closing test tubes, flasks and bottles and for carrying glass tubing into sealed apparatus. The rubber resists acid, alkali and ammonia, and the corks are offered with one hole or with two holes in a wide series of sizes. Chemistry teachers and lab technicians looking for a dependable rubber stopper for lab work in India use them to build gas generators, distillation set-ups and wash bottles. They are supplied by Jain Scientific Equipments Pvt Ltd (ScienceLab), Ambala.
Specifications
| Parameter | Detail |
|---|---|
| Material | Solid, soft rubber |
| Colour | Red |
| Resistance | Acid, alkali and ammonia |
| Bore options | With one hole; with two holes |
| Size range | Top diameter from 9.0 mm to 60.0 mm (full list below) |
Available sizes (all dimensions in mm):
| Top Dia (mm) | Bottom Dia (mm) | Height (mm) |
|---|---|---|
| 9.0 | 6.0 | 16.0 |
| 13.0 | 9.0 | 15.5 |
| 14.0 | 11.0 | 18.5 |
| 16.5 | 13.0 | 20.0 |
| 19.0 | 14.0 | 21.0 |
| 21.0 | 15.0 | 22.0 |
| 22.5 | 17.5 | 23.0 |
| 24.5 | 20.0 | 24.0 |
| 26.0 | 20.0 | 27.5 |
| 26.0 | 21.0 | 27.5 |
| 28.0 | 21.5 | 31.5 |
| 30.0 | 26.0 | 33.0 |
| 33.5 | 30.0 | 33.5 |
| 34.5 | 30.0 | 34.5 |
| 38.5 | 31.0 | 37.0 |
| 41.5 | 32.0 | 42.5 |
| 43.5 | 34.0 | 40.5 |
| 45.0 | 35.0 | 36.5 |
| 49.5 | 40.0 | 40.5 |
| 53.5 | 48.5 | 33.5 |
| 58.0 | 44.0 | 45.0 |
| 60.0 | 51.0 | 56.0 |
Typical Use
A one-hole cork holds a thermometer or a single delivery tube, for example when heating a solid in a boiling tube and leading the gas away to a trough. A two-hole cork lets you fit a thistle funnel and a delivery tube into a conical flask to make a simple gas generator, or build a wash bottle with a long and a short tube. The taper means one size seals a range of neck openings, so the cork should sit roughly one-third to one-half of its height inside the neck.
To choose a size, measure the inside diameter of the neck: it should fall between the bottom and top diameters listed above. Moisten glass tubing with water or glycerol and twist it gently through the hole while protecting your hand with a cloth; never force the glass. Rinse corks after use and keep them away from oils, solvents and direct sunlight, which can harden rubber over time.
Supplier
Jain Scientific Equipments Private Limited, trading as ScienceLab, is based in Ambala, Haryana. Besides the apparatus it manufactures, the company supplies consumables such as rubber corks so that schools, colleges and laboratories in India and international markets can complete their orders in one place. See the company profile for more.
Related Chemistry Lab Equipment
Items that are commonly fitted or used with rubber corks:
- Delivery Tube — glass tubes that pass through a bored cork to carry gas to a gas jar or trough.
- Conical Flask — a common vessel for two-hole cork gas generators.
- Boiling Tube — stoppered with a one-hole cork when heating solids to collect gas.
- Cork Borer Sharpener — keeps borer edges sharp if you enlarge or add holes yourself.
- Cork Stoppers — natural wood corks as an alternative where rubber is not needed.
Browse the Chemistry Lab Equipment category for more.
Frequently Asked Questions
Which sizes can I order?
The sizes in the table run from 9.0 mm to 60.0 mm top diameter, each with its bottom diameter and height. Quote the top and bottom diameter when ordering so we pick the right cork.
How do I find the right size for my flask?
Measure the inside diameter of the neck. Choose a cork whose bottom diameter is a little smaller and whose top diameter is a little larger than that measurement.
Are they available with holes?
Yes, with one hole or with two holes. If you need corks without any hole, please confirm availability through our contact page.
What chemicals do they resist?
The rubber is resistant to acid, alkali and ammonia. For organic solvents or oils, ask us before use, as rubber can swell in such liquids.
How should rubber corks be stored?
Keep them clean and dry in a closed box, away from heat, sunlight and oily materials, so they stay soft and seal well.
Can I order a mixed assortment of sizes?
List the sizes, the bore option and the quantity of each in your enquiry and we will prepare a quotation for the mixed lot.
Request a Quote
Share your size list and quantities through the contact page, or add Rubber Cork to the enquiry cart along with the flasks and tubing it will fit.
Last updated: 24 September 2026
