If the padlock goes through a hasp or a chain, then the hardness and diameter of the shackle are important; the diameter should be at least 9/32 of an inch. Some types of padlocks hide the shackle. Many padlocks only lock at the toe, (emerging portion) but a good padlock will lock at both the toe and the heel (inside portion). The best cylinder to have is either the pin tumbler cylinder or the multilever, but the latter one is difficult to find. A disc tumbler cylinder is not as good, and a warded cylinder is quite inadequate. Good padlocks will also have a key retaining feature. Consumers should avoid padlocks with identification numbers or erase the number, if there is one, because locksmiths can make keys from those numbers. Consumers should always keep locks in the locked position, have all their padlocks keyed alike to avoid an overabundance of keys, and keep control of their keys. Finally, like chains, the staple of the hasp should be sufficiently strong. The hasp should also have concealed screws.