I have several neodymium magnets for sale. They have a very strong magnetic force. I have used one on a string to easily find buried survey pegs and a screw I lost in the lawn/snow, picking up nails (from Bon fire pit or cleaning up after roofing), identifying metals, finding studs (sticks to the drywall screws) etc. The weigh about 16g and have betwee 1000-4000 Gauss magnetic strength, depending on size/manufacturer.
Great for hanging tools or hiding keys.
May be useful for science projects or crafts.
Great for holding pieces of steel while welding.
Holds parts and tools (can be mounted to a wall easily). Can even make magnetic parts bins with a metal bowl by just sticking the magnet to the bowl.
Sew them to a belt for a magnetic tool or magazine holder.
Door stop: I fixed the broken plastic cam latch on my trailer. Simply removed 4 existing screws and used 2 screws(one through pre-existing hole and the other to clamp down an edge) to attach the magnets. May make a nicer backing plate and paint it black to match in the future, but better than having the door close on me.
Used a bolt through one of the pre-drilled holes in the backing plate to attach a mailbox, designed with two slots the screw/bolt head slides into, to a metal shelving unit (or other appliance like a fridge) without drilling holes. Note that in the photo the bolt is too long, but it's what I had available in my spare bolts bin.
Lots available! Bulk purchases welcome.