Pendulum Bobs or Spheres
Product Code : LSK-POM-11189
Pendulum Bobs or Spheres (SKU LSK-POM-11189) are solid turned metal spheres with a small hook, sold as a set of six metals for simple pendulum, oscillation and density practicals. They serve physics benches in senior secondary schools, colleges and polytechnics. The bobs are turned at the Science Lab Supplies factory on Plot 448, HSIIDC Industrial Area, Saha, Ambala, India, which manufactures them and quotes schools, colleges, tender contractors and distributors without any intermediary.
Specifications
Listed below is every specification of the six-metal bob set. In short, the bobs are solid turned spheres of brass, aluminium, copper, zinc, iron and lead, each with a small suspension hook, offered in 12 mm, 18 mm and 25 mm sizes, with single pieces and custom materials also available.
| Specification | Value |
|---|---|
| SKU | LSK-POM-11189 |
| Set | Six different metals, one bob of each |
| Metals | Brass, aluminium, copper, zinc, iron, lead |
| Form | Solid turned spheres |
| Sizes available | 12 mm, 18 mm, 25 mm |
| Suspension | Small hook on each sphere |
| Individual pieces | Available separately |
| Custom options | Other sizes and materials, including non-metals such as wood and plastic |
| Manufacturer | Science Lab Supplies, Saha, Ambala, Haryana |
| Country of origin | India |
Applications and Experiments for the Pendulum Bobs
Hanging a bob of known size on a thread lets students time oscillations and test how the period depends on length but not on mass, using equal-size bobs in different metals. The set belongs on any physics lab equipment list for Class 11 and 12 and suits college mechanics work too.
- CBSE Class 11 practical: studying period against length with a simple pendulum and finding g, timed with School Digital Stopwatches.
- Showing that the period does not depend on bob mass by swapping equal-size bobs of different metals.
- Measuring the bob with a Vernier Caliper to find the effective length to its centre.
- Comparing the densities of the six metals by weighing spheres of equal size.
The lead bob is toxic if residue is swallowed; wash hands after use and keep the set under supervision.
Standard Scope of Supply
The standard set contains six solid spheres, one each of brass, aluminium, copper, zinc, iron and lead, each with a small suspension hook, in the size you choose: 12 mm, 18 mm or 25 mm. Single bobs and custom materials can be quoted. Thread and a clamp stand are not included.
Packing, MOQ and Lead Time
A quotation can be raised for one set, a mix of the three sizes, or individual bobs to replace lost pieces. Each quotation from Science Lab Supplies shows the packing, delivery time and price for the quantities requested, and stopwatches or pendulum stands can join the same quote.
Science Lab Supplies holds an Importer-Exporter Code and is able to ship to buyers in Rwanda, South Africa, Qatar, Sri Lanka, Vietnam and Malaysia. For a price on your bob sizes, write via the contact page, place them in the enquiry cart, or follow tender requirements through the lab tender page.
Frequently Asked Questions
Which sizes are the Pendulum Bobs or Spheres made in?
Three sizes are offered: 12 mm, 18 mm and 25 mm. Each set has six spheres of one size, and different sizes can go on one quotation to suit different stands and thread lengths.
Why does the set include six different metals?
Bobs of equal size but different metals have different masses, so students can show that the period of a pendulum stays the same when only the mass changes, and can also compare the densities of the metals.
Can single bobs be ordered?
Yes. Individual pieces are available, so a lost or damaged sphere can be replaced without buying a full set. Custom sizes and non-metal materials such as wood or plastic can also be made.
Who manufactures these pendulum bobs?
Science Lab Supplies turns the bobs itself at its factory in Saha, Ambala, India, and quotes them as the maker, so your enquiry is answered by the manufacturer rather than by a trading company.
Related Pendulum and Density Apparatus
The items below turn the bob set into complete pendulum and density practicals, adding ready-built pendulum stands, pendulums for advanced college work, timing equipment and density solids in other shapes, any of which can be quoted together with the bobs.
- Six-Metal Pendulum Bob Set — spheres machined to a standard 25 mm diameter, each with a recessed suspension loop.
- Pendulum Set — 300 x 200 mm front plate with a 90°–0°–90° angular scale and a 1 m cord.
- Mathematical Pendulum Demonstration Apparatus — 200 x 125 mm mild steel base with a 50 cm ruler.
- Kater's Reversible Pendulum — 120 x 1.2 cm brass bar with two sets of adjustable knife edges.
- Bifilar Pendulum — cast iron plate of 15 x 10 x 1.5 cm hung from two equal strings.
- Metal Cubes — six-metal cube set for specific gravity, also offered with a hook.
- Digital Stopwatch — 1/100 s resolution with a 24 h timer and alarm.
Browse the full Properties of Matter range, the Applied Mechanics range for compound and torsion pendulums, or all physics lab equipment.
Last updated: 9 October 2026