There are many additional features of Allen key and hexagon keys that makes using the tools much more comfortable. Many time, there are features which aid the location of the key into the fastener, it also improves turning and access to restricted grips, and even prevent fasteners from dropping off the key if locating them in a workpiece.
Ball end: Ball end Torx and hex keys could be placed into the fastener head at a certain angle from the horizontal and vertical, while still enabling anyone to turn the fastener. This could help everyone to gain access to a fastener head in confined and awkward spaces. Depending upon the manufacturer, a ball end hex key could be used to turn a fastener at an angle of up to 30 degrees.
Unlike hex, keys ball ends Allen keys with a ball end features could only turn a fastener at an extreme angle of 25 degrees. Wherever, the higher the edge the hex key could be used at, the narrower the neck of the ball end would be. This also reduces the strength and also increases the chance of its breaking.
Magnetic keys: some Allen keys would be magnetic. This may help to holes a fastener onto the key as it has been removed, or hold the fastener onto the key as it is positioned and screwed onto the work pieces.
Shallow key structure: alley key with a shallow key or stubby design has a shorter short arm than other keys. The shorter arms of stubby keys are approximately half of the length of the equivalent size standard hex keys. They have a tighter inside radius that is required to allow the maximum amount of the short end that could locate into the fastener head. These stubby structures enable them to fit in areas a standard key would not.
Non-magnetic fasteners: different companies have developed a non-magnetic means of holding a fastener onto the end of a hex key, with the manufacturer often creating their own brand name for the feature. Some of the names used by Allen key manufacturers include a magnetic clip or hold.
Twisted shaft: many Allen key manufacturers in India developed this tool by twisting the axis of the keys before them underpasses the heat treatment and tempering processes. They also claim that this would result from the keys flexing less when high torque loads are applied onto it, and so more of the torque Is also transferred to the fastener.
Locking key: some folding key sets are very commonly available with the key which locks into one of the three positions if they are folded out.
Chamfered edges: some Torx and hex keys have a chamfer on the sides. This also aids location into the fastener head and also helps to prevent damage to the corner of the key and fastener head. This unique feature is mostly found on the better quality Torx and hex keys and is one only on ends which so not feature a ball end.