All About Doorknobs
There are two general types of doorknob assemblies, mortise-mounted and bore-mounted. Mortise-mounted hardware relies on a large, rectangular metal box to hold its moving parts. Because of its design, it must be installed into a hand-chiseled cavity that centers at the edge of the door between its inside and outside faces. This type of assembly is expensive to buy and install. Having said that, most mortise style door hardware is of the very highest quality and function.
During the 19th century mortised hardware was practically the only type of door hardware available. And although mortise-mounted hardware is still in wide use, it is used most frequently on exterior doors and sometimes on interior doors in restorations. The lock actions are smoother, more secure and have several features that enhance easy of use and smooth operation.
Because of its high cost, use of mortise hardware on interior doors has yielded to the easier to installation, and far less expensive purchase price, of bore-mounted hardware. Bore-mounted hardware costs less to install because drilling is used instead of chiseling. A drilled installation can literally cut hours off a mortised installation.
Doorknobs fall into the “you get what you pay for” category. Less expensive knobs are made of inexpensive materials and are susceptible to denting, scratches and other kinds of wear and tear. The knobs (or levers) are made of thinner and less expensive metals giving them a flimsy, tinny feel. And if the knob includes a key-lock, the less expensive ones can be easily opened by most amateur burglars.
If the door hardware you’re considering is under $25, chances are the finish will begin to wear off in two or three years if not sooner.
There are two basic styles of bore-mounted hardware: 1) exposed mounting screw type and, 2) the concealed mounting screw type. You can tell which type you have by looking at the escutcheon (trim ring) between the knob and the door. If you can see screw heads in one of the trim rings, you have the exposed mounting screw type. If screws are not visible, then you have the concealed mounting screw type.
In our opinion concealed-screw hardware is better than the exposed-screw style not only because it’s better looking, but because more pressure can be applied to the concealed mounting plates that hold the doorknob in place. With exposed screw hardware, when screw pressure is applied to the trim plate to hold it tightly in place, there is a chance of bending the finished surface. Leaving the screws loose enough to prevent damage to the trim plate can result in the frequent need to retighten the hardware – a nuisance at best. For less maintenance and a cleaner appearance, concealed screw doorknob assemblies are superior.
The Locking method also is an important consideration. There are two basic choices:
• Manual relock key opens latch and changes hardware to unlock position
• Auto relock key opens latch but hardware remains in locked position
The first type, manual relock, must be relocked with a key or the twist of a lever each time it is unlocked with a key. This is the best type of lockset for a bedroom or a bathroom where you don’t want to be accidentally locked out.
The auto relock type is preferred for exterior doors where you don’t want to have to remember to relock the door once you’ve let yourself into your home. This is especially true if you want a door to remain locked at all times even after you have used a key to make entry. Yes, auto relock latches can be set so that they remain unlocked after entry has occurred. You certainly don’t want to lock yourself out after have mowed the back lawn.
Most manufacturers of bore-mounted door hardware use the same two bore sizes:
• A two and one-eight inch hole is used for the handleset
• A one inch bore is used for the bolt assembly
If you want to replace your existing door hardware with another style made by a different manufacturer, chances are you will have no problem accomplishing your goal.