Includes 6 drill bits in the following sizes: 7/8 in (22.2 mm), 3/4 in (19 mm), 5/8 in (15.9 mm), 1/2 in (12.7 mm), 3/8 in (9.5 mm), 1/4 in (6.3 mm). The Pipe Swaging Bits Bearing set is an essential accessory for servicing air conditioners and can meet different tube expansion requirements. Main purpose These swaging tools are designed to be installed on an electric drill and used to expand copper pipes to join two air conditioning copper pipes by swaging. Material and durability Ball bearing steel construction. Swaging tool drill bits are practical and durable, with and uniform hardness, wear resistance, and a elastic limit. Performance and efficiency Wide expansion range and adequate depth support efficient expansion and help reduce operator fatigue. How to use Attach the bit to a compatible electric drill, align with the tube ends, and perform controlled swaging to achieve a clean, tight fit for joining copper pipes. Use scenarios HVAC installation: expand and join copper refrigerant lines during air conditioner installations. Onsite : damaged pipe sections by expanding a replacement tube to fit the existing piping. Refrigeration servicing: service and connect copper pipes in commercial or residential refrigeration systems. Compatibility and application scope Fits standard electric drills and is suitable for expanding copper pipes used in air conditioning and refrigeration piping.