# 1.1.3 Mechanical Joint: Keyway

> From: LOCTITE®X Digital Manual for Bonding (https://www.loctitex.com/en/manuals/bonding/1.1.3-mechanical-joint-keyway/)

#### 1.1.3 Mechanical Joint: Keyway

Keyways transmit torque between a shaft and gear by means of a rectangular key secured to the shaft by dowels, pins or set screws. Machining costs for tolerances required by keyways may be significant. The diameter of a shaft in which a key is seated must be increased by up to 30% to accommodate the key while supporting the torque load.

_Figure 7 Shaped joints with intermediate elements as a key_

![Figure 7 Shaped joints with intermediate elements as a key](/en/manuals/bonding/assets/img/cylindrical-joint-fastening-methods.jpg)

_Figure 8 Fastening methods for cylindrical joints between shaft and element on shaft (gear, pulley) mounted using a keyway and set-screw_

![Figure 8 Fastening methods for cylindrical joints between shaft and element on shaft (gear, pulley) mounted using a keyway and set-screw](/en/manuals/bonding/assets/img/key-keyway-shaft-fastening-methods.jpg)

_Figure 9 Shaft diameter must be increased to accommodate a key_

![Figure 9 Shaft diameter must be increased to accommodate a key](/en/manuals/bonding/assets/img/key-keyway-shaft-fastening-diameter.jpg)