Ace the IGCSE Design & Technology 2026 at JIS – Design Your Success Now!

Vernier calipers are used to measure precise linear dimensions. The tool combines a main scale with a sliding vernier scale, which lets you read measurements more accurately than a standard ruler—often to about 0.02 mm. It can measure external sizes (outside dimensions), internal sizes (like the diameter of a hole), and depths, making it ideal for ensuring components fit correctly in DT work. It isn’t used for measuring mass, marking arcs, or denting metal, which is why those options aren’t suitable.