Does Your Business Hinge on Profit? An Overview of Butt Hinges

Hinges. Do you sell them? Do you service them? Do you replace them? Many locksmiths service the leading edge of the door from top to bottom.

Hinges. Do you sell them? Do you service them? Do you replace them? Many locksmiths service the leading edge of the door from top to bottom. From kick plates to flush bolts and levers to deadbolts, the door gets full attention. You'll even install door closers. But why not examine the profit opportunities from the hinge side as well?

Hinges are jointed devices, where one leaf is attached to the jamb, allowing an attached part, such as a door to swing inward and/or outward. When you research hinges, here's just a sample of what you'll find: cabinet hinges, spring hinges, door hinges, gate hinges, invisible hinges, continuous hinges, furniture hinges, finial-tipped hinges, piano hinges, kitchen cabinet hinges, weld-on hinges, concealed hinges, satin nickel hinges, butt hinges, strap hinges, toy box hinges, window hinges, shutter hinges, glass door hinges, brass hinges, stainless steel hinges, pivot hinges, offset hung pivot sets, center hung pivot sets, specialty hinges and more.

From the standpoint of sales and service opportunity, I decided to concentrate on the most common type of hinge that a locksmith will encounter, the standard industrial butt hinge and some of its variations.


Choices for industrial hinge types include butt hinges, half-mortised hinges, swing clear hinges, spring hinges, inside stop hinges, outside stop industrial hinges, and weld-on hinges. Other features of industrial hinges include unequal leaves, MIL-SPEC, and hinge direction. On non-standard doors and frames, proper operation of the door may require unequal leaves. Extra-thick doors, doors with a decorative veneer, specially designed frames and trim or wall conditions may require the use of special hinges with unequal leaves.

In some government applications, hinges will be specified as MIL-SPEC. As the name implies, all Military Specifications must be met to approve the hinge for usage on the application in question. Some of the numerous special requirements may be hinge leaf and pin length, 'loops and/or tangs' (knuckles) must be designed in a certain fashion, tolerances that need to be met and base material and finish specifications that are allowed and disallowed.

Hinge direction refers to hinges that are non-reversible and must be installed in the proper direction to work as designed.

Physical specifications to consider when searching for industrial hinges include base material, finish material, leaf thickness, leaf length, pin material, pin diameter, knuckle length, open width, hole type, and number of holes. 

Butt hinges are composed of two leaves attached to abutting surfaces of a door and frame, joined by a pin. The pin is contained in the knuckle segment of each hinge leaf. Withdraw the pin and the leaves will separate, allowing the mounted door to be easily removed from the frame. The two leaves are each fitted with screw holes. For installation, both leaves of the hinge are usually fully mortised, one into the edge of the door and one into the edge of the frame. When the door is closed, the leaves meet (or butt together) with only the pin knuckles showing.

Half mortised industrial hinges are butt hinges where only one of the leaves is mortised into the door and the other leaf is attached to the surface of the frame. A half surface hinge is mortised into the frame and the other leaf is attached to the surface of the door.

Swing clear hinges are designed for use in hospitals, institutional or commercial buildings for barrier-free applications, wherever doors are required to meet barrier-free codes (ADA) or are required to swing completely clear of the door opening so that wide equipment can pass through without damaging the doors, frames or equipment. A swing clear hinge projects the door at least 90 degrees out from the opening.

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