Flat keys – ideal for high torque applications
Flat keys are standardized machine elements that ensure a positive-fit connection between a shaft and a hub. They are ideally suited for transmitting high torques and are primarily used where an axially backlash-free, load-bearing connection between components is required. Unlike keyways, flat keys generate radial stress, which means their range of applications is also quite limited. During manufacturing, we adhere to the specified DIN 6886 standard, ensuring a high degree of fit accuracy at all times. Upon request, a wide variety of materials—with or without heat treatment—can be used to customize the flat keys. We can also produce custom designs according to customer specifications—the majority of all required materials are available from stock, ensuring rapid production.
What are flat wedges?
Flat keys are wedge-shaped fasteners featuring a rectangular cross-section and a slight angle, known as the keyway angle. They are inserted into the keyway of the shaft and, when driven in, press against the hub groove to ensure a direct connection and the transmission of high torques. Manufactured in accordance with DIN 6886, which defines dimensions, wedge angles, and tolerances, they can be flexibly installed in numerous machines and devices to ensure maximum efficiency while maintaining cost-effectiveness.
Interesting facts about our flat wedges
Available sizes
| Width | b | 8 - 50 mm |
| Height | h | 4 - 18 mm |
| Length | l | 20 - 400 mm |
Standards, Dimensions, and Materials for Flat Keys
Flat keys are typically manufactured from standard materials such as C45 (quenched and tempered steel), case-hardened steel, or stainless steel (primarily for special requirements). They are standardized according to DIN 6886, while individual designation is based on width, height, and length, supplemented by the respective shape of the flat key—for example, with or without a head. Since they are inserted via a keyway, precise machining is necessary to ensure high functionality. At Crummenerl GmbH, we therefore place great emphasis on dimensional accuracy and surface quality to ensure optimal performance of the flat keys.
How do flat keys work?
While conventional keyways rely solely on a form fit, flat keys also create a force fit. This creates radial pressure between the shaft and hub that can withstand the transmission of high torques. The combination of force fit and form fit means that flat keys have a higher overall torque transmission capacity, reduce relative movement between components, and even allow for alternating directions of rotation, provided the flat keys are installed correctly.
The advantages of flat keys at a glance
The special design of flat keys and their adapted shape offer a variety of different advantages—and are primarily used when keyways reach their load limits. The advantages include:
- High torque transmission: The additional clamping force of the flat keys enables high torque transmission
- Backlash-free fit: Flat keys sit securely between the shaft and hub and ensure smooth operation
- High load capacity: Flat keys are particularly robust against fluctuating loads and are therefore also particularly cost-effective
- Power transmission: Due to their robustness, flat keys are ideally suited for medium to high power transmission
Buy flat keys to DIN 6886 and custom-made products online
Flat keys are high-performance machine components that enable a heavy-duty, backlash-free shaft-hub connection. If you’re looking to buy flat keys online, Crummenerl GmbH is the right place for you!
We offer not only standard flat keys in accordance with DIN 6886, but also custom-made solutions tailored to your specifications. As a specialized manufacturer in the field of CNC machining since 1955, we leverage our extensive expertise to produce high-quality components that meet the most demanding requirements.
In addition to careful and precise workmanship, what sets us apart is our extensive inventory, where nearly all common materials are in stock. This allows us to fulfill custom orders and special requests from our customers promptly, efficiently, and cost-effectively. If you have any questions about our flat wedges, you can easily get in touch with us via our contact form.