KW1 vs SC1: How to Tell Which House Key You Have

Trying to figure out whether you have a KW1 or SC1 house key? Start with the key itself. In most cases, you can identify the right keyway by checking the stamp, the number, or the grooves on the blade.

This becomes especially important when you’re ordering a replacement key blank from our website because KW1 and SC1 keys are not interchangeable. A KW1 blank is made for Kwikset-style locks, while an SC1 blank is made for Schlage-style locks. If the blank doesn’t match your lock’s keyway, it won’t fit or work correctly once cut.

Let’s figure out which type of key you have.

The stamp and blade shape are usually more reliable than the head shape. On a basic house key, the head shape can be a helpful clue because standard KW1 and SC1 keys do look different. But the stamp is still the best place to start because it usually tells you the actual key blank type.

When ordering one of our keys, this matters a lot. The design on top can look different from the plain key you use now. The blade still needs to match your lock’s keyway, so choose the keyway first and the design second.

Let’s figure out what type of key you have.

Step 1: Check the Stamp on the Key

Flip your key over and look at the head, which is the part you hold when you turn the key. You should see some numbers and letters stamped right there.

If your key says KW1, you have a KW1 keyway. If it says SC1, you have an SC1 keyway.

You may also see a number instead of the keyway name. A 66 usually points to a Kwikset KW1 key blank. A 68 usually points to a Schlage SC1 key blank.

If you see a KW1 or SC1, great, you know your keyway and you're already ahead of the game. If the stamp is worn down or you just can't make it out, no worries. Keep reading.

Step 2: Look at the Grooves on the Blade

Next, look at the blade, i.e. the long metal part that slides into the lock. KW1 and SC1 keys have different groove patterns, which is why they fit different locks.

How to Identify a KW1 Key

Side 1

Looking at the front face of the key you'll see two grooves running the full length of the blade. The main narrow groove sits slightly off center to the right and runs flat to the edge. To the left of it is a wider groove that runs all the way to the left edge of the blade.

Side 2 

Flip it over and the layout shifts. The narrow groove is now on the left side of the blade, followed by a flat section in the middle and then a wider groove on the right that runs all the way to the right edge of the blade.

If both sides match what you see here you've got a KW1.

How to Identify an SC1 Key

Side 1

Looking at the front face of the key you'll see two grooves running the full length of the blade, a narrow groove sitting slightly off center and a wider groove to the left of it. The SC1 and USA stamps are visible on the shoulder just below the bow.

Side 2

Flip it over and this side has a single narrow groove only, running the full length of the blade slightly off center to the left.

If this matches your key you've probably got an SC1 keyway.

Step 3: Look for the Numbers

If you still aren't sure, look for a number stamped on your key, most commonly a 66 or a 68. If you see a 66, you have a Kwikset KW1 key.

If you see a 68, you have a Schlage SC1. At this point, between the stamp, the grooves, and the numbers, you should have a pretty clear answer.

Step 4: Don't Rely on the Head Shape Alone

The top of the key can help, especially if you’re looking at a basic KW1 or SC1 house key. A standard KW1 key often has a five-sided head with multiple cutouts. A standard SC1 key often has a wider or more diamond-shaped head with a single keyring hole.

That said, don’t rely on head shape alone. Some keys from the same brand family can use different keyways, and the head shape can vary once you start looking at decorative or printed key blanks. The part that matters most is the blade. If the blade doesn’t match the lock’s keyway, the key won’t fit or work correctly once cut

What If You Still Can't Tell?

If the stamp is gone and the groove pattern isn’t clear, compare your key to product photos before ordering. You can also take the key to a local locksmith or hardware store and ask them to identify the blank type.

You can also send us an email and we'll do our best to help. Make sure to include a clear photo of both sides of your key.

Final Thoughts on KW1 vs. SC1 Keys

Most of the time, people don’t need to think about what type of house key they have. But when you’re ordering a replacement key blank from CustomKeys.com, it suddenly becomes important.

Look for the stamp first. Then check for the blank number. After that, compare the grooves on the blade. If your key says KW1 or 66, choose a KW1 blank.

If your key says SC1 or 68, choose an SC1 blank. And if you’re still not sure, ask a locksmith or send us a photo before placing your order.