Measuring a flush-mounted Hinge is simple, but the order in which you take the measurements is important. hinge dimensions are always given in the standard height × width format, supplemented by a few secondary dimensions.

Key Dimensions

1. Height (Length)

· Measurement Method: Open the hinge and measure vertically along the length of the hinge leaves, parallel to the center pin/axis (from top to bottom).

· Significance: This is the primary dimension designation (for example, a “4-inch hinge” indicates that its height is 4 inches).

2. Total Width (Unfolded Width)

· Measurement Method: Fully unfold the hinge and lay it flat. Starting from the outer edge of the left hinge leaf, measure horizontally to the outer edge of the right hinge leaf (including the center pin area).

· Note: The width should be measured with the hinge fully unfolded and laid flat, rather than by measuring individual hinge leaves, unless otherwise specified by the manufacturer.

3. Hinge Leaf Thickness

· Measurement Method: Use a vernier caliper or precision ruler to measure the thickness of a single metal plate (hinge leaf).

· Common Dimensions: Standard residential hinges typically range in thickness from 0.085 inches to 0.096 inches, while heavy-duty commercial hinges range from 0.134 inches to 0.180 inches.

Supplementary Measurement Specifications

When replacing or matching existing hinges, you should also check the following:

· Corner Radius: Observe the corner of the hinge leaf.

  · Right Angle: A sharp 90-degree angle.

  · Fillet: The standard fillet radius is 1/4 inch (similar to the curve of a U.S. one-cent coin) or 5/8 inch (similar to the curve of a U.S. five-cent coin).

· Hole Layout/Spacing: Measure the distance between the centers of adjacent screw holes to ensure that the new screw holes align with the existing mortise holes.