Lasting post: Standard lasts have a hinge so they can be “cracked”, which makes the distance between the toe and heel shorter; the last needs to be “cracked” at the hinge so you can get the last out of a shoe without tearing up the top of the heel seam. This means that each last has a hole in the top of it that fits exactly into the top of the lasting post. Once the last is on the post, a sharp tug will cause it to crack and the shoe can be safely removed from the last.
Re: making a lasting post, I appreciate this idea, posted on the Shoemaking Forum facebook page by Bill Shanor, along with this comment: “I grind the threads for about two inches from the top, round the top so that I can rub and open seams, and have more than one length of bolt. Oh, and if you use the bolt to remove “pesky” lasts, a hardened one is in order. I’ve bent several unhardened bolts over the years”.