Residential & Commercial Security - Locks, Keys & Dead Bolts - Weiser/Kwikset/Schlage Question

Two questions:

1. How can I tell if my existing door locks are Kwikset, Schlage, or another brand? There are no markings that I can tell.

2. We're looking at a new front door lock/handle, and it is Weiser. Is this compatible with Kwikset or Schlage?

A lock's brand name is usually stamped into the latch plate. If there is no name, it's usually a made-in-China el cheapo.
These mostly use the Schlage "C" keyway or the Dexter/Kwikset keyway.
By "compatible" I assume you mean similar keyway, so as to fit one key to all locks. Generally, a Kwikset key can be made to fit a Weiser lock, but not vice-versa. Neither is compatible with Schlage. In SOME cases, aftermarket cylinders can be ordered from your local locksmith to fit into SOME types of locks.

rstripe is on the money again.

Your keys probably have a number on them that would identify the type of keyway.

Schlage = SC1 as standard
Kwikset = KW1 as standard

There are other keyblank manufaturers that use differing numbers but largely, we can tell what brand of lock you have if you divulge the number on the key.

Generally, a Kwikset key can be made to fit a Weiser lock, but not vice-versa.

rstripe -
I need to have a kwikset key open a weiser lock. I had a kwikset blank cut to my weiser profile. They key looks almost completely identical and fits the weiser keyway, but won't turn. How can I accomplish this? Thanks!

The weiser lock needs to be re-keyed to the kwikset key,

Weiser pins are different in size to Kwikset, but that is not your problem. The Weiser key sits lower in the profile of the keyway and duplicating onto a kwikset key will not have the kwikset key sit correctly in the keyway profile, hence why the kwikset key will not operate.

If the Weiser key was repositioned properly in the key machine vice before the duplication occurred, the Kwikset copy might work.

If the Weiser lock is fairly new, with original pins and keys, a duplicated key on a Kwiwset blank should work. But if the Weiser is worn, and/or your sample key is not original (ie. a multi-generational duplicate itself) the duplicated key may not be supported "high" enough in the keyway to operate, as GlobalLocky has indicated. Tell the smithy to use a .015" shim under the Weiser key before duplicating onto a Kwikset blank.
If that still won't work, take the lock to the smithy so he can key it.