Reloading dies are generally sold in sets of two or three dies, depending on the shape of the case. A three die set is needed for straight cases, while a two die set is used for bottlenecked cases. The first die of either set performs the sizing and decapping operation. The middle die in a three die set is used to expand the case mouth of straight cases, while in a two die set the entire neck is expanded as the case is extracted from the first die. The last die in the set seats the bullet and may apply a crimp. Special crimping dies are often used to apply a stronger crimp after the bullet is seated.

Standard dies are made from hardened steel, and require that the case be lubricated, for the resizing operation. Rifle cartridges require lubrication of every case, due to the large amount of force required, while smaller, thinner handgun cartridges can get away with alternating lubricated and unlubricated cases. Carbide dies have a ring of tungsten carbide, which do not require lubrication.

Reloading dies are generally threaded with 7/8-14 (or, for the case of .50 BMG dies, with 1-1/4x12) threads and are interchangeable with all common brands of presses, although older dies may use other threads and be press-specific.