We have mounted a very powerful 3/4" diameter x 3/4" cylinder N42 grade neodymium-iron-boron magnet in 6061 aluminum for industrial use, and attached it to a high-grade Delrin (Acetal Resin) handle. It also has a removable vinyl cap to protect the magnet when not in use. Perfect for high volume gold and silver buying shops, scrap yards and metal recyclers, auto shops, hardware stores, just to name a few. Identify/sorting some types of costume (fake) jewelry, which often use steel as the base material under the plating. Identify and sort steel grades and metal alloys that contain iron or cobalt. Identify/sort chrome plated items from polished aluminum, silver, and non-magnetic grades of stainless steel. Identify/sort solid brass and bronze from plated steel items. Test rocks for iron content, which often indicate extraterrestrial origin! (Meteorites) Also handy for science experiments involving ferromagnetism. The magnet insert is rated at 33 lbs (as with all magnets, this rating depends on the magnet mating to a smooth, flat, unpainted steel surface). Dimensions are: 1" (25mm) diameter x 1-1/4" (32mm) tall head, 6-1/4" (155mm) overall length, 1" (25mm) diameter x 3.25" (80mm) handle. The aluminum casing protects the magnet from chipping and breaking, and makes removing iron and steel shavings much easier. These are made in the USA. Jewelry: The magnet should always be the first test you perform on an unknown piece of jewelry. If there is any steel, iron, or nickel present, the magnet will let you know. These metals are common in costume jewelry where they are electroplated with gold or silver, but they will never be present in high quality jewelry (with the possible exception of clasps, which sometimes have steel springs inside them). It is important to note, however, that not all fake jewelry will have these metals present because there are other non-magnetic metals than can be used as a base.