The MTS-032 High-strength Precision Hook Broaches Machined from tungsten steel, this product features sharp and durable edge. It can be used to carve various lines on plastic model surfaces. This product includes 5 precision hook broaches in sizes of 0.1mm, 0.3mm, 0.5mm, 0.8mm and 1.0mm. The shank diameter is 3.175mm.