We have two versions of them respectively made from NdFeB magnet and ferrite magnet. NdFeB version features superior holding force while ferrite version is cheaper in price. Above that, they all share the same physical structure which is proved to be effective in utilizing magnetic field to generate great holding force. Besides, all needs to be done to promote the sturdiness of the product is done --- steel cup is coated (normally with Zn), NdFeB magnet is coated (normally with CuNi), filling material keeps it clean between magnet and steel cup.
The structure makes the pot magnet with threaded hole perfect choices working as bases. Screw-in a bar with matching thread and hang whatever you need on it —the pot magnet at the bottom will hold firmly enough that you do no worry about its falling down. Use two of them described above and you can hang a horizontal banner in between. Use NdFeB pot magnet in big diameter to support a big, heavy sign in a mall, etc.
We have rubber boots designed for these pot magnets aiming at protecting the holding surface. We have seen people use rubber boot and this internal thread pot magnet to hold antenna on cars.