3 1/2" Hinges with a 5/8" Radius are designed for doors and frames
that use rounded-corner hinge mortises rather than square corners. The 5/8" radius refers
to the curved corners on the hinge leaf, which must match the door’s existing cutout to ensure
a flush fit and proper alignment.
Using the correct radius hinge is especially important when replacing existing hardware or
working with older or pre-mortised doors. Installing a square-corner hinge in a rounded mortise
can lead to uneven gaps, binding, or the need for additional chiseling. Matching the radius
helps the door swing smoothly and sit correctly in the frame.
These 3 1/2" hinges are built to standard residential specifications and are commonly
used on interior doors such as bedrooms, closets, and hallways. When matched to the correct
door weight and application, they provide reliable performance and straightforward installation.
3 1/2" Hinges with 5/8" Radius FAQ▾
What does a 5/8" radius mean on a hinge?
A 5/8" radius means the corners of the hinge leaf are rounded with a 5/8-inch curve
instead of square corners. This shape is designed to match rounded hinge mortises in doors
and frames.
Why is hinge radius important?
Matching the hinge radius to the door’s mortise allows the hinge to sit flush. Using the
wrong radius can cause fit issues, uneven door gaps, or require extra modification to the
door or frame.
Are 3 1/2" 5/8"-radius hinges standard?
Yes. 3 1/2" hinges with a 5/8" radius are a common residential size, especially
on interior doors that were factory-mortised for rounded-corner hinges.
When should I choose radius hinges instead of square-corner hinges?
Choose radius hinges when replacing existing rounded-corner hinges or when your door and
frame are already cut for a 5/8" radius. This ensures proper fit, smoother operation,
and a cleaner finished look.
