Features This pipe expander is mainly used to expand copper pipes and connect the two copper pipes tightly when installing the air conditioner. Made of high‑quality bearing steel material, with high strength and hardness, good wear resistance. These expanders are designed with hexagonal shank and are suitable for installation on various manual electric drills. The kit contains 5 sizes of expanders, suitable for different air‑conditioning copper pipe expansion. Can maintain good ductility during the expansion process, which can prevent the copper pipe from cracking and leaking. Specification: Item Type: Tube Expander Material: Bearing steel Surface Treatment: Blackening Shank Diameter: 1/4in (approx. 6.35mm / 0.3in) hex handle Specifications: 3/4in (approx. 19mm / 0.75in), 5/8in (approx. 15.9mm / 0.6in), 1/2in (approx. 12.7mm / 0.5in), 3/8in (approx. 9.5mm / 0.4in), 1/4in (approx. 6.3mm / 0.25in) Package List:5 x Tube Expander Package List 5 x Tube Expander