I've used them occasionally in my home workshop for about two decades. You can buy replacement nuts for them if the nut is lost or worn out, but after many uses I decided to buy a new set as mine were starting to show noticeable wear. I like the very simple and reliable way of attaching the U-bolts to the spring. compressed. Nothing can slip and slide away from you, unlike some of the more common "hook" knots on the market. Lubricate heavy lead screws and nuts with gear oil or chassis grease before each use, as this will ease both. Use and extend the life of the large bolt and nut. They are cut with an unusual "tapered thread" used for very heavy duty applications and different from the hardware you normally see. After all, it's great to buy a tool twice, 20 years apart, and find that the new one looks exactly like the old one, barring wear and tear. You usually see where compromises have been made to reduce manufacturing costs, but not in this case.