We used to sell gobs of these hard drive magnets, we still have some left. You can get these if you take a computer hard drive apart, but these are larger than most and if time is money then you may as well buy them here! What you get, for $2 is an assembly, each assembly contains two crescent shaped magnets about 2 inches long and 1/10 inch thick (these dimensions may vary slightly and what you get may not be quite exactly what's in the picture but it will be very close). These are impressive, each magnet can pick up about 25 pounds of steel! Be careful if you get your fingers between them!!! Of course each magnet has a steel 'bracket' behind it which serves as a nice handle
We'll include with each order an #9 torx bit so you can disassemble them (the right allen wrench will work too). These are really handy for holding tarps down to trucks, table cloths on folding tables, catching steel head trout etc.
In the picture you can see the assembly, and then below the ruler is one of the magnets as they look after you get this little assembly apart (two screws have to be removed.