Du-Bro Fully Threaded Rods 4-40 Part No: 379. Can be used in conjunction with our nylon or steel Kwik-Links or with ball links where extra long pushrods are needed. Bendable and strong. Rods are fully threaded \(.072" rods w/2-56 thread\) \(.093" rods w/4-40 thread\). Fully threaded rods are stainless steel, perfect for making custom lengths for your needs.