Rubber Corks (with Two Holes) Manufacturer,Supplier and Exporter in India
Product Code : EL-SLE-4719
Jlab Export is a leading Rubber Corks (with Two Holes) Manufacturer,and suppliers in India
Rubber Corks (with Two Holes) (code EL-SLE-4719) are rubber stoppers bored twice, so that two glass tubes — for example a thistle funnel and a delivery tube — can pass through one sealed mouth. They fit test tubes, 24 mm boiling tubes and 250 ml flasks, come in sizes No. 2, 7 and 13, and are packed one hundred per pack for gas-preparation practicals. The corks are made by Jain Laboratory Instruments Pvt Ltd (JLab) at its works in Ambala, India.
Specifications
| Parameter | Detail |
|---|---|
| Type | Rubber cork (stopper) with two holes |
| Sizes | No. 2, No. 7 and No. 13 |
| Material | Rubber |
| Designed for | Test tubes, 24 mm boiling tubes and 250 ml flasks |
| Quality check | Each pack is visually inspected before dispatch |
| Pack quantity | Pack of 100 corks |
| Minimum order quantity | 10 units |
| Dispatch time | Usually 7–10 working days |
| Product code | EL-SLE-4719 |
| Manufacturer | Jain Laboratory Instruments Pvt Ltd (JLab) — OEM |
| Country of origin | India (made in Ambala, Haryana) |
What Is a Two-Hole Rubber Cork Used For?
The classic use is laboratory gas preparation. A flask or boiling tube holds the reactants, a thistle funnel through one hole lets acid be added, and a bent delivery tube through the other hole leads the gas away to a gas jar or a test solution. School chemistry practicals use this arrangement to prepare hydrogen from zinc granules and dilute sulphuric acid, or carbon dioxide from marble chips and dilute hydrochloric acid, and then to test the gas. The same cork serves any set-up that needs a separate inlet and outlet, such as bubbling air or gas through a liquid, or a home-made wash bottle.
When assembling a gas generator, push the thistle funnel down until its stem dips below the liquid, so that the gas can leave only through the delivery tube. Lubricate each glass tube with water or glycerine and protect your hand with a cloth as you twist it into the cork. Check that the delivery tube is open before the reaction starts, and keep flames away when hydrogen is being produced.
What to Specify When Ordering
- Cork number — No. 2, 7 or 13, matched to the test tube, 24 mm boiling tube or 250 ml flask you use.
- Tube diameters — the outside diameter of the thistle funnel stem and delivery tube, so the holes can be confirmed.
- Number of packs — 100 corks per pack, with a minimum order of 10 units.
- Glassware for complete set-ups — thistle funnels, delivery tubes and gas jars can be quoted together.
Frequently Asked Questions
What experiments need a two-hole cork?
Mainly gas preparation, where a thistle funnel and a delivery tube must both pass through the stopper of a flask or boiling tube. It is also used for any apparatus that needs one tube in and one tube out.
What is the diameter of the holes?
It is not stated in the listing. Give JLab the outside diameter of the tubes you plan to insert along with the cork number, and the fit will be confirmed in the quotation.
Which cork number fits a 250 ml flask?
The listing names No. 2, 7 and 13 for test tubes, 24 mm boiling tubes and 250 ml flasks without pairing them one to one. State the flask or tube you are using and JLab will supply the matching number.
Why must the thistle funnel dip into the liquid?
If the stem ends above the liquid, the gas escapes up the funnel instead of through the delivery tube. Keeping the stem below the surface seals that path and sends the gas to the collecting jar.
Do the corks come with funnels or tubes fitted?
No. Each pack contains the two-hole corks only; thistle funnels, delivery tubes and gas jars are listed separately and can be added to the order.
What should I include in an export enquiry?
Quantity and sizes, the destination country with port or city, the delivery terms you prefer (FOB, CIF or similar), packing or labelling instructions, and any tender number.
Who is the manufacturer?
JLab — Jain Laboratory Instruments Pvt Ltd — makes these corks at its works in Ambala, Haryana, India.
OEM Manufacturer
JLab is the trading name of Jain Laboratory Instruments Pvt Ltd, a school and college laboratory equipment manufacturer in India, incorporated in 2017 with its base on Hargolal Road, Ambala, Haryana. Two-hole corks are made at JLab’s own works, not sourced from a trader, so schools, colleges, dealers and importers deal with the factory directly, receive packs that have each been visually inspected, and reorder from the same manufacturer. JLab exports worldwide and ships to buyers in every region — for example South Korea in East Asia, the Philippines in Southeast Asia, Austria in Western Europe, Papua New Guinea in Oceania and Uruguay in South America. For institutional purchasing, see the JLab lab tenders page.
Gas Preparation Items
- Thistle Funnel — a stout-walled thistle funnel to pass through one hole of the cork.
- Delivery Tube Glass — straight and bent soda lime glass delivery tubes for the second hole.
- Gas Jar with Lid, Glass — for collecting the gas produced.
- Cork Borer — plated brass cutting tubes with a handle and clearing rod, for enlarging or adding holes.
- Rubber Corks (with One Hole) — the single-hole version in the same sizes.
See the complete School Lab Equipment range.
Request a Quote
Quotations are issued directly by the manufacturer. Press Add To Cart on this page, or use the contact page to send the number of packs (10 or more), the cork sizes, the diameters of the tubes to be fitted, any funnels or delivery tubes you also need, and the delivery address.
Last updated: 4 October 2026
