Carmex Thread Mills Solid Carbide - With Through Coolant - Metric - M12 x 1.75 - MT7Carmex MTB Thread Mills Solid Carbide with Through Coolant are precision tools designed for engineers and machinists who demand clean, accurate internal threads and reliable, long lasting performance. This MT7 shank, metric thread mill is built for M12 x 1. 75 threading and uses a through bore cooling system to improve productivity in CNC environments. Through coolant bore: Coolant is channeled through the tool bore to reach the cutting edges,