Bar Breaking Apparatus
Product Code : LSK-PL-10352
Bar Breaking Apparatus (SKU LSK-PL-10352) is a heavy cast iron frame carrying a stout iron bar, used to show the very large forces produced when a metal bar expands and contracts with temperature. A nut at one end takes up the slack and the other end is drilled to take a cast iron breaking bar, which snaps as the heated bar cools. Frame and bar are manufactured by Science Lab Supplies at Plot 448, HSIIDC Industrial Area, Saha, Ambala, and the manufacturer quotes schools, colleges, tender contractors and distributors directly.
Specifications
The frame, bar and fittings of the bar breaker are set out one per row. In short, a heavy cast iron frame holds a stout iron bar; one end of the bar carries a nut to take up slack, and the other end is drilled to accept the cast iron breaking bar, the piece that fails in the demonstration.
| Specification | Value |
|---|---|
| SKU | LSK-PL-10352 |
| Frame | Heavy cast iron |
| Main bar | Stout iron bar |
| Tensioning end | Fitted with a nut to take up slack |
| Breaking end | Drilled to accept a cast iron breaking bar |
| Breaking piece | Cast iron breaking bar |
| Manufacturer | Science Lab Supplies, Saha, Ambala, Haryana |
| Country of origin | India |
Applications and Experiments for the Bar Breaking Apparatus
The iron bar is heated strongly, for example over a Bunsen Burner (Pack of Two), the nut is tightened to remove slack, and the bar is left to cool. As it contracts it pulls against the cast iron breaking bar until that bar snaps, showing the force of thermal contraction with heat and thermodynamics lab equipment.
- NCERT Class 11 physics, thermal properties of matter: thermal expansion and thermal stress.
- Everyday engineering links: expansion gaps in railway lines, bridges and pipelines.
- B.Sc. and engineering physics: introducing thermal stress in a restrained bar.
Standard Scope of Supply
The apparatus is supplied as described above: the heavy cast iron frame with its stout iron bar and tensioning nut, drilled to accept a cast iron breaking bar. Because each demonstration breaks one bar, tell us how many breaking bars you want and they will be itemised on the quotation.
Packing, MOQ and Lead Time
One apparatus for a demonstration bench or several for a group of institutions can be quoted, each quotation giving packing, delivery time and price for the quantity. Spare breaking bars and other thermal-expansion items can be added to the same document.
Science Lab Supplies, an IEC-holding registered exporter, is able to ship to buyers in Zambia, Rwanda, South Africa, Qatar, Sri Lanka and Vietnam. The business is registered under Udyam as a manufacturing enterprise (UDYAM-HR-01-0014546) and for GST (GSTIN 06ADEPJ0574F2ZU). State the number of frames and spare breaking bars on the contact page or in the enquiry cart; a heat-lab tender can be routed through the lab tender page.
Frequently Asked Questions
What does the Bar Breaking Apparatus demonstrate?
It shows the large force produced when a restrained metal bar changes length with temperature. As the heated iron bar cools and contracts, it snaps the cast iron breaking bar held at its drilled end.
Why is the breaking bar made of cast iron?
Cast iron is brittle, so it fractures cleanly instead of bending when the contracting bar pulls on it, which makes the result dramatic and easy to see from across the room.
Is the demonstration hazardous?
Yes, it involves a very hot bar and a sudden fracture. A teacher should perform it, students should stand back, and eye protection such as the polycarbonate Safety Goggles, 12 pcs should be worn.
Is Science Lab Supplies the manufacturer?
Yes. The cast iron frame, iron bar and nut are produced at the company’s own factory in Saha, Ambala, India, so your quotation comes from the people who make the apparatus and not from a trading firm.
Related Thermal Expansion Apparatus
These Physics Lab and Heat items extend the lesson: a bimetallic strip, two ball-and-ring sets, a steam-jacket expansion rod and a pyrometer for expansion of solids, a ring for comparing heat conduction in metals, and a drop-weight kit for comparing material hardness. All of them can be added to one quotation.
- Bimetallic Strip — brass and steel riveted with heat-resistant rivets on a wooden handle.
- Ball and Ring Apparatus — 22 mm brass ball and brass ring on separate rods.
- Ball and Ring Apparatus (Heat) — ball that passes through the ring cold but not when heated.
- Linear Expansion Apparatus — heat jacket with three inlet tubes; steam source not provided.
- Pyrometer — all-metal apparatus with engraved scale, three test rods and a spirit furnace.
- Conductivity Ring — four metal strips heated gently at the centre to melt wax.
- Hardness Tester Kit — drop-weight rig with anvil, punch and pre-cut samples.
Browse the full Physics Lab range, the Heat range, or all physics lab equipment.
Last updated: 22 October 2026
