This carriage screw is a genuine manufacturer sourced replacement part. It is specially designed for use with Toro snowblowers. This screw is generally used to secure the scraper blade. The square area under the head is designed to fit into a square hole in the workpiece. It is this square hole that restrains the screw and keeps it from t...Read moreurning when the nut is tightened. Please note, this screw is made out of metal and it is sold individually.