Authentic replacement cutters for Simple Woodturning Tools - Simple Rougher (tool engraved with SR). This package contains 1 each of the following three cutters: 1) 90° Square Carbide Cutter. This cutter features very sharp corners with no radius. Size is 14mm x 14mm. Best choice for turning perfect 90 degree shapes such as inside corners and tenons. 2) 6" Radius Carbide Square Cutter. This cutter features rounded corners with an approximate 0.02 inch radius. Size is 15mm x 15mm. Best choice for roughing and cutting straight surfaces. 3) 4" Radius Carbide Square Cutter. This cutter features corners that are very sharp with virtually no radius. Size is 15mm x 15mm. Best choice for turning straight profiles and nearly 90° inside corners. These cutters will fit full size tools (engraved with SR). They will not fit the mid size tools (engraved with MSR). Any questions, please send us a question below.