Increase the efficiency of your woodworking projects with our Screw-On Mortise Bit Arbors. With a 1/2" shank and 5/16-24 threads, these arbors are designed for precise and secure screw-on attachments. With a length of 1 3/4", they are suitable for various projects and compatible with different mortise bits. Trust our expertise for quality and ease in your woodworking endeavors.