Iron, which is still very common in Europe, is also a forged metal. If untreated, iron will bleed or rust, depending on the environment. In most cases, iron is powder coated to retard this natural occurrence. The black finish for which iron is often associated is popular for a rustic or barn-like appearance.

Stainless steel is typically a high-end, modern, or contemporary choice for door hardware. Like forged brass, it has a very smooth, clean-lined surface, and has been a popular material used by Italian- and German-based companies. This metal is often used in coastal environments, where salt-water air tarnishes most metals quickly. When selecting stainless-steel hardware, it is important to research products to be sure the lock mechanisms will not corrode. Not all stainless-steel hardware is appropriate for coastal conditions. Price typically dictates quality of finish.

Selecting & Specifying Hardware

Hardware choices and selections are governed by the function of the door, the style and type of hardware that most suitably meets the door's operating requirements, and both the appearance and the tacit signals the designer wishes to convey, such as push, pull and turn.

Hardware selection begins with lock functions. Important conditions and considerations include the following:

Entry−This refers to an exterior door with keyed access, which can be provided in single cylinder or double cylinder functions.

• Mortise Lock−Recommended for use with heavy or high-use doors. Specific trim selections require this type of lock. It is an integrated lock (see Glossary). Technical attributes of a mortise lock include saw proof inserts in the deadbolts, push button locking capacity, and emergency egress function (single operation exit). Highly recommended for use with grip handle and thumb latch application.
• Deadbolts−Usually combined with a lever or knob function or a push/pull plate.

Patio−This is an exterior door that does not require key access, but requires lock function, and is typically used on doors that access a balcony or patio. The same lock choices as entries apply, mortise lock or deadbolt. In most cases, exterior doors have keyed access from the outside in, to overcome potential redundancy-of-locking situations. This occurs when several doors are in close proximity to each other or when external access is directed towards a single door.

Privacy−This function has three locking options, all with varying levels of security and use.

• Mortise lock−The most secure locking feature for high-use areas.
• Mortise bolt−Although this locking mechanism is not substantially stronger than the push-button locking spring latch, it offers a more identifiable locking feature. For example, this may be used for a bathroom door so that it is more obvious that the door is locked, as opposed to a push button mechanism.
• Spring latch (locking)−This is the most affordable locking mechanism. It is not necessarily weaker than the mortise bolt, but it is less obvious that the mechanism is actually locked.

Passage−This is a non-locking mechanism with operable handles. It is used on doors that do not need to be secured.

• Spring latch−This is a latch operated by a handle.
• Mortise lock box−While there is no locking capacity, it has the same mortise box as a locking mechanism, and functions as a latch.

Dummy−This refers to a set of inoperable handles on one or both sides of a door. This could also be the inoperable side of a double door condition. Dummies are often used with a roller catch or another latching mechanism.

Multi-point−Originally developed in Europe, this mechanism latches the doorframe in three or more places. Many American window companies have adopted this system.