Kudos to the poster that recently said to just double up back to back the US General bar magnets HF gives out as freebies.
I had a few hanging around (with no real need prior for them) but did want to attach something to the big lid of my new bulk storage cart.
My first thought was to use a couple of the round 60lb pull magnets HF sells for like $3 apiece to attach one of these bars.
I was already using that type of magnets for my Milwaukee M12 stick light, much less expensive than the OEM option and holds great

but the doubling up of the bar even sets it off a bit further away from the lid than the round magnets would, and then ratchets anvils fit when facing the lid and helps to locate them from sliding around at all.
Lets face it the quality control on these "free" magnet bars leaves a little bit to be desired

some magnets are just about flush with rolled metal outside edge others are set in deeper and some of the backs of the steel bar channel are slightly rounded and don't sit flat against a solid surface. Seems to vary with the different part# they have. Though obviously when wall screw mounting them don't much matter.
I also have used one, my best flat surface one a for socket rail too.