Hinges play an important role in many products. They are found on everything from doors and cabinets to industrial machinery, access panels and more. A key feature of many hinges is mounting holes. One of the most common types of mounting holes is countersunk. What are countersunk mounting holes exactly, and why do hinges have them>
The Basics of Mounting Holes
Mounting holes are exactly what they sound like: holes used to mount hinges to a surface or object. With the exception of weld-on and living hinges, nearly all hinges have mounting holes. Some of them have two mounting holes per leaf, whereas others have three or more mounting holes per leaf.
To install a hinge, you’ll typically need to drive fasteners, such as bolts, through the mounting holes and into the adjacent surface or object. If a hinge has four total mounting holes, you’ll need to use four fasteners. If it has six total holes, you’ll need to use six fasteners. Regardless, mounting holes serve as openings for fasteners, which are needed to install hinges.
Common types of mounting holes include the following:
- Countersunk
- Counterbore
- Round
- Square
- V-notch
- Notch radius end
- Notch square end
Countersunk Mounting Holes Explained
Countersunk mounting holes are characterized by an angular or conical shape. They are designed to fit fasteners so that the heads sit flush with the surface of the hinge leafs.
Not all mounting holes consist of a straight hole. Countersunk mounting holes feature an alternative shape that allows for a flush fit with fasteners. They are angular or conical so that the fastener heads don’t protrude out of the hinge leafs. Instead, the fastener heads will sit flush with the hinge leafs. The depth and diameter of countersunk mounting holes feature specific measurements to fit specific fastener sizes.
The Benefits of Countersunk Mounting Holes
Why should you choose hinges with countersunk mounting holes? With their angular shape, countersunk mounting holes protect against snagging and scratching. Fastener heads can scratch or snag surfaces and objects. Hinge with countersunk holes, however, have flush fastener heads to prevent this from happening.
Countersunk mounting holes also promote a clean, polished appearance. Protruding fasteners look messy. If you’re planning to use a hinge in an area where it will be visible, you may want to choose a hinge with countersunk mounting holes for this reason. The flush fastener heads offer a higher level of aesthetics.