GOOD NEWS. . . . The PICTURE UPLOAD FUNCTION IS WORKING !!! The tech folks at the parent company have been able to remedy the issue. You can upload pictures once again. Thank you for your patience.
I's a specialized bolt with a long shaft on it. But, to answer our question, the thread is 1/4-20, and it's about 1-1/2 inches long. The threads are only near the head of the bolt, maybe 3/8 inch, with the rest as shaft.