Screw Pipe Clamp (Hoffman Clamp)
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Product Code : SCL-CL-11561
Screw Pipe Clamp (Hoffman Clamp) (SKU SCL-CL-11561) is a nickel plated steel screw clamp that squeezes flexible tubing to reduce or stop the flow of a liquid or gas. It suits tubing up to 16 mm and is used in chemistry practicals and gas-preparation set-ups in schools and colleges. The clamp is supplied by Science Lab Supplies from Ambala, India to schools, colleges, training institutes, tender contractors and distributors.
Specifications
The Hoffman clamp is made of nickel plated steel for a 16 mm pipe. A projection plate stops the end of the screw from damaging the tubing, and a hinged bottom bar lets the clamp be fitted to and removed from a tube without reaching either end of it.
| Parameter | Value |
|---|---|
| SKU | SCL-CL-11561 |
| Also known as | Hoffman clamp, screw pinchcock |
| Tubing size | 16 mm pipe |
| Material | Nickel plated steel |
| Tube protection | Projection plate under the screw end |
| Fitting | Hinged bottom bar, fits without access to tube ends |
| Supplied by | Science Lab Supplies, Ambala, India |
Applications and Experiments for the Hoffman Clamp
Turning the screw presses the tubing closed a little at a time, so the clamp gives fine control of flow rather than a simple on or off. That makes it useful wherever gas or liquid runs through rubber tubing in a teaching laboratory, from gas preparation to siphons and wash bottles.
- Class 10–12 chemistry: controlling gas flow from a generator during preparation of gases.
- B.Sc. chemistry: regulating flow in tubing on distillation and filtration set-ups.
- Physics and biology labs: closing off rubber tubing on manometers, siphons and respirometers.
Standard Scope of Supply
The Screw Pipe Clamp (Hoffman Clamp) is supplied as a single unit as described above, complete with its screw, projection plate and hinged bottom bar. Rubber tubing is not part of the clamp; any optional accessories are listed on the quotation.
Packing, MOQ and Lead Time
Request a price for a few clamps or a full class set. The quotation will state packing, delivery time and price for the number you ask for, and rubber tubing, stoppers and other chemistry lab equipment in India from our catalogue can appear on the same quotation.
Science Lab Supplies holds an Importer-Exporter Code as a registered exporter, so it can ship to buyers in Bangladesh, Zambia, Rwanda, South Africa, Qatar and Sri Lanka. You can reach the team through the contact page, build a list in the enquiry cart, or see the lab tender page for bulk procurement.
Frequently Asked Questions
What tubing size does this clamp fit?
It is made for a 16 mm pipe, which covers the rubber tubing commonly used on school and college laboratory set-ups.
Can it be fitted without disconnecting the tubing?
Yes. The hinged bottom bar opens so the clamp can be placed on or taken off a tube without access to either end.
Who supplies the Screw Pipe Clamp (Hoffman Clamp)?
Science Lab Supplies supplies it from Ambala, India and quotes it both for individual laboratories and for tender contractors and distributors.
How is it different from a Mohr clamp?
A Hoffman clamp uses a screw to adjust flow gradually, while a Mohr clamp is a spring clamp used mainly to open or close tubing.
Related Tubing and Clamp Items
The Hoffman clamp works on flexible tubing joined to glassware through bored stoppers. These items complete that assembly, and the spring-type clamp gives a second way of closing a tube, so a whole gas or liquid train can be ordered on one quotation.
- Elastic Clamp for Rubber Pipes (Mohr Clamp) — spring clamp for closing tubing.
- Rubber Tube (Laboratory) — the tubing the clamp acts on.
- Rubber Stoppers of Various Diameters with Holes — for connecting tubing to glassware.
- Glass Tubes of Different Diameters — glass connectors used with the tubing.
Browse the full Chemistry Lab range or all school lab equipment.
Last updated: 25 September 2026
