Bộ 6 thước đo đường kính 8-150mm chất lượng

Material: carbon steel Product specifications: 8-150mm (6 pcs) Process: nickel plating on the surface Features: The surface of the telescopic rod is smooth, its side head curvature is good, the surface of the product is nickel-plated, the product has a long service life and the outer surface is bright. How to use: The spring piston that telescopes in the hole (or groove) can detect the inner diameter, and then measure the reading with a micrometer or caliper (with a knurled locking device at the end)