*Save by Buying from the Machine Key Manufacturer

Save by Buying from the Machine Key Manufacturer

All machine keys are in stock, shipping within 48 hours from USA

Machine Keystock Express’ goal is to offer lower prices on machine key stock and ready-to-use machine key sizes than other sellers.

All listed items are in stock and we ship our machine keys from the USA quickly! We ship only to the USA and Canada.

This website’s online store sells small quantities to retail customers of ready-to-ship machine keys that are in stock. For large quantity wholesale machine key orders or special order machine keys you need us to manufacture quickly, please visit our wholesale website.

Machine Keystock Express manufactures machine keys of the highest quality that meet ISO 9001 certifications. Our machine keys are manufactured with SS304 stainless steel and SC45 carbon steel and alloy steel in many sizes.

If you normally buy machine key stock to make your own machine keys, you may find it cheaper to buy our ready-made keys in the sizes you need, which can be less costly than your labor needed to work with key stock.

We manufacture several kinds of machine keys in many sizes:

  • Woodruff keys are half-circle shapes, with radius or flat bottoms. DIN-6888.
  • Parallel keys are rectangular shapes with ends that are square (DIN-6885-B), round (DIN-6885-A), or both (DIN-6885-AB). We have in stock ready-to-use keys in inch and metric sizes
  • Key stock is very long so you can cut it into whatever size machine keys you need. We have ready-to-ship key stock in inch and metric sizes.

Need Wholesale Quantities?

We have the lowest prices and can manufacture
any kind of precision machine keys or parts you need.
Visit our wholesale site and we’ll provide a price quote 

What Are Machine Keys, Also Known as Shaft Keys?

Machine keys are used in power transmission to transmit torque between a shaft and a shaft mounted component such as a gear, pulley, or coupling. Both the shaft and the component must be machined with a keyway of the appropriate size and style for the key to be used.

Machine keys are sometimes called shaft keys, or sunk keys, and are available in a variety of types and include Parallel Keys, Flat Keys, Woodruff Keys, Square Keys, Rectangular Keys, Plain Taper Keys, Gib-Head Taper Keys, Perpendicular Pins and the Feather Key.

Machine Keys have a wide range of applications in our daily lives. Machine Keys hold machinery parts in place or align components. Machine Keys are used in power transmissions, motors, speed reducers, variators, automobiles, motorcycles, and industrial machines.

Each machine key has few attributes such as width, height, length, finish, and tolerance. It is important to understand the tolerance attribute. There are two type of tolerance. 


An oversize tolerance machine key provides a slightly tighter fit and an undersize tolerance machine key provides a slightly looser fit. Tolerance is specified in standards such as DIN6885 and JIS B 1301. Machine keys with metric (mm) measurement are almost always made as close tolerance undersized, whereas machine keys with imperial measurement (inch) tend to be made in both oversize and undersize tolerance sizes.

Sometimes the term machine key and keystock are used interchangeably. However, the term keystock refers to a “stock” of material that is 300mm, 1 foot or longer in length, and from which machine keys are made. Machine key refers to a finished product that is installation ready. Keystock is often used in post market repairs or small production. Keystock and machine keys are made from material such as carbon steel, stainless steel or alloy steel.

Parallel Machine Keys

Parallel keys are the most widely used. They have a square or rectangular cross-section. Parallel keys include Square Keys, Rectangular Keys. The shaft is usually key slotted for the full length for the shaft or slotted from the end of the shaft and along the length of the shaft for a distance greater than the length of the key to be used. Parallel keys can be installed by lining up the keyslots in the shaft and the component and then pressing the parallel key between the slots. There are three shapes of parallel keys depending on the ends of the keys. The end of a key can be either square or radius or round. The type of ends are referred to as “Forms”. Form A refers to a round end and Form B refers to a square end. For a Form A key, both ends are round, sometimes called the double round key. Form B key has both ends square. Form AB is a key with one end round and one end square, sometimes called the single round key. 


Woodruff Keys

A woodruff key is a half moon shaped key that is inserted into a curved slot in the shaft. Woodruff keys are machined metal fasteners used to transfer torque from a shaft to gears where tight tolerances and functionality are vital. They are precisely a fail-safe device to ensure that the key breaks before the gears do, cutting replacement costs down significantly. Woodruff keys are used in a variety of applications including, lawn and garden equipment, automobiles, trucks, pumps, electric motors, agricultural equipment and other heavy equipment. They are used more often than machine keys in automated assemblies, such as automotive, because they are easier to feed and maintain tight tolerances. No matter the application, the woodruff key’s job is the same, to transfer the torque by locking the gears into the crank shaft. 

Machine Key Standards

There are two sets of standards in the world – one for the imperial (inch) and another for metric (mm). DIN 6885 and JIS B 1301 deals with metric keys and ANSI B17.1 and BS 46 deals with imperial machine keys. These standards define the material, dimensions, tolerance and finish of the keys. There is a great similarity between DIN 6885 and JIS B 1301-1996. DIN 6885 is more popular in Europe and JIS in Asia.

  • ANSI B17.1 By American National Standard Institute
  • DIN6885 from German
  • JIS B 1301-1996 from Japan
  • BS 46 from England
  • GB 1567-2003 from China

Let Machine Keystock ship your machine keystock to you fast as the lowest price!

Need Small Quantities Fast?

This is our retail website for small quantities of the most popular machine keys shipped within 48 hours.

Get a Wholesale Quote

We are a leading machine key manufacturer of any kind of machine key. Because we manufacture our own high-quality parts we offer the lowest prices. Visit our wholesale site to get a quote.