Screws, nuts and bolts are distinguished by their size, diameter, thread count and style of head, such as pan heads, hex heads and machine bolts. Identify different types of screws, nuts and bolts with helpful information from an experienced woodworker in this free video on home repair tools.Expert: Dave Trull Contact: www.trullgallery.com/ Bio: Dave Trull has been in the woodworking business for 18 years, and he got into woodworking way back in the early ’70s. Filmmaker: Christopher Rokosz