A Guide to Builders Hardware Terminology

General Information

The builders hardware industry like most others has its own jargon. Since the industry is small and practiced by relatively few people, this jargon is not as well known as it should be.

The industry is known as a mature industry in that it is over 200 years old and changes come about slowly. Terms used over a hundred years ago are still used today though not particularly applicable. One good example is "lockset" which years ago was "set locks" or "set lox”. It came about from the practice of selling the lock body and operating trim separately. Hence, one bad to order a "set of locks" or the lock body, a spindle, a cylinder, a thumbturn, two operating knobs, two escutcheons, etc. to make up a complete set.
'Until about 40 years ago, architects, builders and code officials were not required to have much technical knowledge about builders hardware because very little in the way of codes, regulations or standards pertained to hardware.

Hardware, however, is a key element in providing for (1) means of egress, (2) security, and (3) making buildings accessible to and usable by people with physical disabilities. There have recently been established a number of requirements creating security ordinances, regulations affecting the, disabled, and model code egress requirement. Unfortunately, these have resulted in conflicts and differences among industries heretofore not concerned with one another. The debates over the extent of the use or non-use of door closers or double cylinder dead locks are examples of this.

During the same period of time when changes affecting hardware occurred, the manner in which hardware and doors were marketed underwent certain changes. This overlapping of distribution channels has tended both to simplify and complicate hardware terminology. Terms used in both industries have been brought together but, to the credit or discredit of the old timers, very few have been discarded. For example, "backset" to a hinge or door person may mean the distance between the edge of a hinge preparation and the stop in the frame. To a lock person, "backset" is generally the distance from the center of the cylinder to the edge of the door.

The hardware terms explained in this publication are grouped under broad classifications and areas subject to code provisions are touched upon.

Almost all of the hardware items described have been listed or labeled by a nationally recognized independent testing laboratory and are under an in-plant follow-up inspection service. Except for spring hinges labeled for use on fire doors, hinges and pivots are not listed or labeled.

Note:This glossary has been prepared by the Builders Hardware Manufacturers Association, Inc. (BHMA). It was done because of a request for a glossary received from one of the model code groups. An attempt has been made to go beyond the format of a glossary and include information clarifying the nature of some builders hardware products so that a better understanding might result. An attempt has also been made to avoid the insertion of any material that could be regarded as self-serving or that could be construed as interpreting any code provisions. Where code criteria have been cited, they have been taken only from the latest editions of the National, Standard, or Uniform Building Codes and the Life Safety Code. There has been no effort whatsoever to recognize or discuss any unique local or regional requirements.

The ANSI standards cited in connection with types of builders hardware products were sponsored by BHMA and approved by the American National Standards Institute, Inc. under its canvass method. This information is included for the reader's information and, except in very limited instances, has nothing to do with Model Building Code or Life Safety Code criteria. This material may be reproduced and credit to BHMA is requested.