Swaging Tool Drill Bit SetSize: 1/4'' (6.35mm), 3/8'' (9.5mm), 1/2'' (12.7mm), 5/8'' (15.9mm), 3/4'' (19mm), 7/8'' (22mm). Shank Diameter: 1/4 inch hex shank. Tube ExpanderCome with 6 different sizes for your choice to meet your needs. Suitable for hard and soft copper standardized, easy to braze swaging set. Durable and durableMade of high-quality steel with high hardness and uniformity, wear-resistant. High elastic limit, good performance and long life! Swaging toolWhen installing the air conditioner, use a pipe expander to widen the copper pipe, so that the two copper pipes can be accurately and perfectly connected to each other. Easy to UseThey needs to be installed on hand electric drill. Flaring tool drill bit set are small in size, so you can take it with you wherever you want to use it!