Baer Heli Coil Tap - Wire Thread Insert - Bottoming Tap (STI) - UNC - 1.1/2 x 6Baer Heli Coil Tap the specialized bottoming tap designed for precision thread repairs and secure wire thread insert installations. Crafted to form clean UNC threads for 1 1 2" diameter, 6 TPI, this tap is the reliable foundation you need whenever youre incorporating Heli Coil style inserts into metal parts. Built to support durable, repeatable repairs, its a must have for any shop that demands strong, long lasting threaded connections. Key benefits