Chat software by BoldChat
Toll Free: 800-265-3078 email:
Open Menu

Hinge Terminology

Plain or Standard Assembly 

 1. Plain or Standard Assembly
- leaves lay flat in the same plane in an open position

Pitch Paint Clearance End Play 

 9. Pitch
- the dimension from a point on the knuckle to the same point on the next knuckle on the same leaf

 Reverse Assembly
Reverse Assembly Closed

 2. Reverse Assembly
- opposing leaves extend laterally from opposite sides of the pin
- leaves will not close to a parallel position


 10. Swaging
- forming one or both leaves, within the proximity of the paint clearance, toward or beyond the center of the pin (swaging slightly increases the width of a hinge)

 Hinge Length Leaf Width

 3. Length
- the length of the hinge measured parallel to the pin

 One Leaf Half Swaged

 10.1 One Leaf Half Swaged
- one leaf half swaged one half the pin diameter

 Hinge Width Leaf

 4. Width
- the overall dimension of the leaves measured perpendicular to, or across the pin

 One Leaf Full Swaged

 10.2 One Leaf Full Swaged
- one leaf swaged equal to the pin diameter and both leaves parallel when in closed position

 Hinge Width Leaf

 5. Leaf
- the portion of the hinge extending laterally from the knuckle, which is curled around a pin

 Both Leaves Half Swaged

 10.3 Both Leaves Half Swaged
- both leaves swaged approx. one half the pin diameter with a minimum clearance between the leaves when parallel

 Hinge Length Leaf Width

 5.1 Leaf Width
- the dimension from the center of the pin to the outer edge of the leaf

 Reverse Swaged

 10.4 Reverse Swaged
- one leaf swaged to simulate reverse assembly
- leaves will not close to a parallel position


 6. Knuckle
- the hollow circular part at the joint of a hinge through which a pin is passed (other terms for this are loop, joint, node, curl, and barrel)

 Center Swaged

 10.5 Center Swaged
- both leaves swaged by one half the pin diameter plus one half the material thickness so that both leaves are symmetrical on the center line
- leaves will not close to a parallel position

 Inside Knuckle Diameter
Oustide Knuckle Diameter

 6.1 Inside Knuckle Diameter
(also called Pin Diameter)

 6.2 Outside Knuckle Diameter


 11. Offset
- one or both leaves formed in the proximity of the paint clearance, away from the center of the pin
- when both leaves are offset and in a closed and parallel position, the dimension between the leaves will be greater than the pin diameter (reduces the width)

 Pitch Paint Clearance End Play

 6.3 Knuckle Length
- the nominal dimension of the knuckle measured parallel to the pin

 Stop Hinge

 12. Stop Hinge
- a hinge manufactured to limit the travel of the leaves to a specified angle

 Pitch Paint Clearance End Play

 7. Paint Clearance
- the minimum dimension between the outer face of the knuckle and the opposing edge of the cutout, over the entire range of pivotal movement of the hinge

 Stop Hinge Outside

 12.1 Stop Hinge, Outside
- leaves will move from an open or flat position and stop at a specified angle

 Pitch Paint Clearance End Play

 8. End Play
- the amount of axial movement between the leaves

 Stop Hinge Inside

 12.2 Stop Hinge, Inside
- leaves will open from a closed position (leaves parallel to each other) and stop at a specified angle


 8.1 Side Play
- the amount of movement of the leaves perpendicular to the pin (occurs when inside knuckle diameter is larger than the pin)


 12.3 QAL Stop Hinge
- a stop hinge with the quick-a-line feature

13. Quick-A-Line Hinges:

 A continuous hinge manufactured with a weld guide feature.


  1. Means of  rapidly aligning the hinge to the stock for welding purposes.
    Result: reduces labour costs
  2. Means of preventing paint or finish loss from the barrel (joint), which is the most observable part of the hinge when mounted.
    Result: improves the appearance

Available in the following sizes:

  • 0.030" thick steel with 0.090" steel pin (1/4" knuckles)
  • 0.060" thick steel with 0.125" steel pin (1" knuckles)

Standard length is 72" but can be made to customer specifications.

14. Pin Assembly for Continuous Hinges:

Types of pin retention include:

  • staking
  • press tightening
  • welding the pin to end knuckles
  • crimping end knuckles
  • forming or folding pin ends (to facilitate removal)