Rubber Corks (with One Hole) Manufacturer,Supplier and Exporter in India

Product Code : EL-SLE-4718
Jlab Export is a leading Rubber Corks (with One Hole) Manufacturer,and suppliers in India

Rubber Corks (with One Hole) (code EL-SLE-4718) are bored rubber stoppers that seal a test tube, a 24 mm boiling tube or a 250 ml flask while letting a single glass tube or thermometer pass through. They are offered in sizes No. 2, 7 and 13, in packs of one hundred, for school chemistry, physics and biology set-ups. JLab (Jain Laboratory Instruments Pvt Ltd) makes them at its works in Ambala, India.

Specifications

Solid, One-Hole or Two-Hole: Which Cork Do You Need?

All three JLab listings give the same cork numbers (No. 2, 7 and 13), the same vessels and the same pack of one hundred, so the number of holes is the only listed difference. Order the one-hole cork whenever just one tube or probe has to pass through the stopper.

What Is a One-Hole Rubber Cork Used For?

The single hole lets a glass tube, a thermometer or a dropper stem pass through the stopper while the rest of the mouth stays sealed. Typical school uses are a delivery tube that carries carbon dioxide from a test tube of chalk and acid into lime water, a thermometer held in a boiling tube to follow a temperature change, and simple distillation or condensation demonstrations built from a boiling tube and bent glass tubing. Biology classes use the same cork to fit a tube into a respiration or germination set-up.

To fit glass tubing, wet the tube end and the hole with water or a drop of glycerine, wrap your hand in a cloth, hold the glass close to the cork and push it through with a gentle twist; never force it, as a snapped tube can cut the hand. Make sure any heated apparatus always has an open outlet, and remove the glass from the cork after the lesson so the rubber does not grip it permanently.

What to Specify When Ordering

• Cork number — No. 2, 7 or 13, or the tube or flask the cork has to fit.
• What goes through the hole — the outside diameter of the glass tubing or thermometer, so the hole can be confirmed.
• Number of packs — each pack holds 100 corks; the minimum order is 10 units.
• Matching glass — delivery tubes, glass tubing and thermometers can go on the same enquiry.

Frequently Asked Questions

What size is the hole?
The listing does not give the hole diameter. Tell JLab the outside diameter of the tube or thermometer you will insert and the cork number you need, and the fit will be confirmed with your quotation.

Which vessels do these corks fit?
They are designed for test tubes, 24 mm boiling tubes and 250 ml flasks, in cork numbers 2, 7 and 13. Name the vessel when ordering so the right number is supplied.

How do I push a glass tube through the cork safely?
Lubricate the glass and the hole with water or glycerine, protect your hand with a cloth, grip the tube close to the cork and twist it in gently. Fire-polished tube ends go in more easily and are less likely to tear the rubber.

How is this different from the two-hole cork?
Only in the number of holes. Use one hole for a single tube or thermometer; choose the two-hole cork when a funnel and a delivery tube, or an inlet and an outlet, must pass through the same stopper.

Are glass tubes or thermometers included?
No. This listing is for the corks only; delivery tubes, glass tubing and thermometers are separate JLab items linked below and can be added to the same order.

What details does an export quotation need?
Send the number of packs and cork sizes, the destination country and port or city, preferred delivery terms such as FOB or CIF, any labelling or packing needs, and a tender reference where one applies.

Who makes these corks?
Jain Laboratory Instruments Pvt Ltd, trading as JLab, manufactures them at its works in Ambala, Haryana, India, and quotes for them directly.

OEM Manufacturer

JLab is the trading name of Jain Laboratory Instruments Pvt Ltd, an Indian manufacturer of chemistry lab equipment, physics apparatus and school lab consumables, incorporated in 2017 and located on Hargolal Road, Ambala, Haryana. The one-hole corks are produced at JLab’s own works and not bought from a trader, which lets schools, colleges, dealers and importers order them factory-direct with a visual check of every pack and repeat supply from the same maker. JLab exports worldwide and ships to buyers in every region — for example South Korea in East Asia, South Africa in Southern Africa, Spain in Southern Europe, Malaysia in Southeast Asia and the Czech Republic in Eastern Europe. Tender buyers can refer to the JLab lab tenders page.

Glass and Corks to Order Together

• Delivery Tube Glass — straight and bent soda lime glass delivery tubes for gas-collection set-ups.
• Glass Tubing — soda glass tubing and capillary to cut to length for your apparatus.
• Thermometers — glass laboratory thermometers to fit through the cork.
• Rubber Corks (with Two Holes) — the two-hole version in the same sizes.
• Rubber Corks (without Holes) — solid corks for simply closing tubes and flasks.

More school lab consumables are listed under School Lab Equipment.

Request a Quote

You get the quotation straight from the manufacturer. Click Add To Cart on this page or write through the contact page with the number of packs (minimum 10), the cork numbers, the diameter of the tube or thermometer that will pass through the hole, and where the goods should be delivered.

Last updated: 4 October 2026