Hinge Terminology
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Leaf
That portion of a hinge extending laterally from the knuckle, which generally revolves around the pin.
Pin
That portion of a hinge that runs axially through the inside of the knuckles about which the leaves revolve.
Knuckle
The hollow circular part at the joint of a hinge through which a pin is passed. (Sometimes called loop, joint, node or curl.)
Knuckle Length
The nominal or typical dimension of the knuckle measured parallel to the pin.
Hinge Length
The length of the leaves measured parallel to the pin.
Hinge Width
The over-all dimension of the leaves measured perpendicular to or across the pin.
Leaf Width
The dimension from the center of the pin to the outer edge of the leaf.
Pitch
The dimension from a point on the knuckle to the same point on an adjacent knuckle on the same leaf.
End Play
The amount of axial movement between the leaves.
Paint Clearance
The minimum distance between the outer face of the knuckle and the opposing edge of the leaf cutout over the entire range of pivotal movement on the hinge.
Plain or Standard Assembly
Neither leaf swaged, leaves lay flat in the same plane in an open position.
Reverse Assembly
Neither leaf swaged, opposing leaves extend laterally from opposite sides of the pin. Leaves will not close to a parallel position.
Offset
Forming one or both leaves 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.
Swaging
Forming one or both leaves with the proximity of the paint clearance toward or beyond the center of the pin.
One Leaf Half Swaged
One leaf swaged one half the pin diameter.
One Leaf Full Swaged
One leaf swaged equal to the pin diameter. Both leaves will be parallel when in a closed position.
Reverse Swaged
One leaf swaged to simulate reverse assembly. Leaves will not close to a parallel position.
Both Leaves Half Swaged
Both leaves swaged approximately one half the pin diameter with a minimum clearance between the leaves when parallel.
Stop Hinge
A hinge manufactured to limit the travel of the leaves to a specified angle.
Stop Hinge, Outside
Leaves will move from an open or flat position and stop at a specified angle.
Stop Hinge, Inside
Leaves will open from a closed position (leaves parallel to each other) to a stop angle as specified.
Staked Pin
Upsetting the knuckle(s) of one leaf to secure the pin and prevent axial movement of the pin in the knuckle. Staking is usually located on the bottom of the knuckle in a uniform consistent pattern.
Lock Punch
A temporary method of preventing leaf rotation by upsetting material from to adjacent knuckles to remove end play. Lock punching is usually located on the bottom of the knuckle in a uniform consistent pattern.
Side Play
Lateral Movement of the leaves caused by clearance between the inside diameter of the knuckles and the diameter of the pin.
Back Angle
The angle described by the leaves when the hinge is rotated to its full open position. Back angle is usually a minimum of 270¡.
Spun Pin
Cold forming one or both end of the pin to a diameter greater than the inside diameter to prevent axial movement. Pins Spun at both ends are most commonly specified for tamper-proof applications.
Standard Cutoff
A hinge with an even number of full length knuckles, the assembly plan view lower leaf having a knuckle at the left and a notch at the right, and the upper leaf having a notch at he left end and a knuckle at the right. Standard cutoff refers to hinges of plain assembly only.
Opposite Standard Cutoff
Opposite to above with lower leaf with a notch at the left end and a knuckle at the right, etc.
