Back when a door knob was just a door knob to me and that's as deep as it got, I never imagined how different each door knob could be. I'm not talking about the obvious design difference, of course there are many varieties there, but what about the measurements, the latches, the round or square, handleset, lever mortise, multi point, yadda yadda... And honestly you wont need to know all this stuff, unless you are trying to replace your hardware. I know that might sound super overwhelming, but don't give up yet! It's actually not all that bad. You just need to find out what type of hardware you have and then you can start crossing off most of that list.
First, you need to determine if you have an actual standard door knob/lever. This is what most people have today. And how you determine this is by the door prep, or measurements of the holes in the door. Standard doors have a 2 1/8" bore hole and 1" cross bore, and backset measurements of either 2 3/8" or 2 3/4" (for more info on standard door prep check here, or check here for more info on backsets). And by looking at the edge of the door where the bolt (or latch) comes in and out of the door when the knob is turned (the latch is what holds the door in place when shut), will help you find out what style of latch you need for your standard door. There are 3 different styles of latches for standard doors, rounded corner, square corner, or drive-in.
Most of the hardware you order come standard with either the square or rounded corner faceplates. Generally you will need to request a drive-in latch. Make sure and read in the description of what style will ship with the hardware, and if it's not what you need you can request for it at no extra charge.
You may run into what looks similar to the door levers above, but the backset measurement is not anywhere close to 2 3/8" or 2 3/4", it's more like 5".
If you have a separate deadbolt and knob/lever you can use a deadbolt with either a passage function knob/lever or keyed entrance if you want the added security. And this also falls under the standard prepped door measurements.
Standard entrance handlesets (also standard prepped) you can find under any brand. Entrance handlesets are most popular for any front door.
Sideplates are similar to handlesets without the big long grip at the bottom. Some are made to fit standard prep of 5 1/2" cc, but there are many that have a 3 5/8" cc (which is not standard).
Multi Point Patio Lock trims are high end patio doors that have their very own internal mechanism and locks with 3 or more points around the top, side and bottom of the door. On the edge of the door it will look like the latch extends for several feet or maybe even the entire edge of the door. We have many trim sets (the mechanism is not included) to choose from.
Skeleton Key Locks fit older style doors prepped for a mortise box that slides into the edge of the door. The skeleton key lock boxes measure about 3" deep and 4" tall and 1/2" thick. Nostalgic Warehouse is where you will find your replacements for this style.
Mortise Handlesets and Locks are high quality and are generally add more security than a regular handleset or door lock. Mortise locks use a mortise lock box (similar to the sekeleton key lock box) that slides into the edge of the door. It measures at around 3-4" deep and about 8" high (you can see how high the mortise box is if you look at the edge of the door). It's more modern than the skeleton key locks. You can find these modern mortise handlesets and locks from Emtek.
Still Unsure what you need? Check out our Door Hardware Replacement Guide