Resources, Advice & Tips for Covid-19
Read More

Antique Skeleton Key Identification Guide

Kate Miller-Wilson
Old skeleton keys

Learn how to unlock the mysteries of old-fashioned keys, called skeleton keys. Antique skeleton key identification is a bit of an art, since many keys were unmarked. There are clues, however, if you know where to look. This identification guide can help.

Do You Have a Skeleton Key?

Technically, a skeleton key is a key that features a unique shape at the end to unlock a warded lock, or a lock that has some specific obstructions inside it that must be pushed out of the way with the key. However, people regularly use the term "skeleton key" to refer to three different types of keys:

  • Skeleton key - Featuring a solid shaft, these keys have a pre-cut bit pattern and may fit many different locks. Because of its solid shaft, a skeleton key weighs much more than its hollow counterparts.
  • Bit key - Cut from a key blank, these keys have a standard shape but a unique bit pattern to fit a specific lock.
  • Barrel key - Shaped like skeleton key, these are lighter because they have a hollow shaft or barrel that allows them to slide over a post or pin in the lock. These keys are lighter in weight because they contain less metal.
  • Interchangeable key - An Interchangeable key, or master key, often had changable bits you could adjust to fit various locks. They are uncommon.
  • Sewing machine keys - You'll often see sewing machine keys sold as skeleton keys. These small keys have a barrel and no bit. They were used with treadle sewing machines.

Important Factors in Antique Skeleton Key Identification

If you have an old key, there are several things to consider as you try to learn a bit more about it. Look for the following features.

Skeleton Key Size

Skeleton keys come in all different sizes - from less than an inch to over five inches long. The size of your key may offer clues about its purpose:

  • Tiny keys - Very little keys often open jewelry boxes and other small locks.
  • Small keys - Small skeleton keys, under two and a half or three inches in length, sometimes open cabinets and furniture.
  • Medium-sized keys - Keys ranging from two and a half to four inches long were likely made to open doors. You may find them sold with antique doorknobs.
  • Very large keys - The biggest keys opened gates, large locks, and other substantial pieces.
skeleton key sizes

Age of the Key

It can be very difficult to determine the age of an old key, but there are a few clues that can help. A few keys are stamped with a date, but this is uncommon. Most skeleton keys you encounter are from 1940 and before, but some keys are very old. Examine the key to determine whether it appears handmade. If it is not uniform or appears to be hand-worked, it could be an older example.

Skeleton Key Material

Many skeleton keys are made of brass, but some can also be made of iron. You can tell whether your key is brass or iron by learning to identify brass. One of the best ways to do this is to use a magnet. If the key sticks to the magnet, it is probably iron. If it does not, it is probably brass.

Engravings on Skeleton Keys

Some keys feature engravings that can help you establish a provenance or story for the key. You may notice tags with hotel names on them or specific room numbers. There are keys that include the lock manufacturer's name stamped on them, such as Corbin keys. If your key has an engraving of any kind, you may be able to research it to learn more.

Skeleton Key Bow Shape

The bow of the key is the wider part you hold in your hand, and antique skeleton keys can feature very interesting and unique bow designs. Some feature recognizable motifs, such as a lion. Others are shaped like a heart or another fancy shape. Keys with interesting bows can be among the most valuable to collectors.

Antique skeleton key bow shape

Are Old Skeleton Keys Worth Anything?

Most individual skeleton keys sell for $10 or less, but certain styles can be worth much more. Keys with fancy bows, interesting engravings, a fascinating history, or other special features can be worth hundreds of dollars. Old key identification is also about assigning value, so you should look at similar keys that have sold recently and compare yours. Here are some recently sold examples:

Antique Skeleton Keys Are Fun to Collect

Although they can be difficult to identify, old skeleton keys are fun to collect. Because they come in so many shapes and sizes, there is nearly infinite variety in the options. They are also an affordable item to collect if you are starting a new hobby. They look great displayed in your home as well.

Was this page useful?
Antique Skeleton Key Identification Guide