Baer Hexagon Die Nut HSS - Metric Coarse - Left Hand - For General use - M39 x 4.0The Baer Hexagon Die Nut HSS is a durable, generalpurpose tool designed to repair or refresh damaged threads with precision. Built for metalworkers and DIYers alike, its lefthand, metric coarse design (M39 x 4. 0) delivers dependable performance in routine threading tasks. Hexagon body for grip: Six flats provide secure manual control or easy wrench engagement in tight spaces. Lefthand orientation: Designed to engage damaged or dirty threads