Power Fist

A Power Fist (also known as a Power Glove) is essentially an over-sized, armoured gauntlet that generates an energy field around it that disrupts any solid matter it touches. It is a favoured close combat weapon for the warriors of the Imperium of Man, as well as the Forces of Chaos (particularly the Chaos Space Marines). It is an iconic weapon of the Loyalist Space Marines. It is large and slow in combat, and so the bearer must be willing to risk the blows of his enemy before he can strike back. The benefits of the Power Fist are that it increases the user's strength, much as Power Armour does due to the power provided by the mechanical servos that allow the Power Fist to move as its user desires. The disadvantages of its unwieldy nature are often well worth the limitations, however, as as the combination of the disruptive power field and sheer physical strength afforded by a Power Fist allows a Space Marine to pulverize and tear apart armour plate from the most well-protected of vehicles, and to wound and kill even colossal monstrous creatures in close combat; its brutal effects against more mundane foes goes without saying. It is most commonly found fitted to Space Marine Tactical Dreadnought (Terminator) Armour.

A variant of the Power Fist is the Chainfist, which is similar to a Power Fist but has a miniature chainsaw blade attached. A popular choice for weapons used with a Power Fist are the combat shield and the bolt pistol or just a Storm Shield, to ensure that the combatant survives long enough to use it.

Other Imperial forces also make use of the Power Fist as well, including the Sisters of Battle, and though less common, officers from the Imperial Guard may also make use of human-scaled versions of the Power Fist that are mounted on a partial exoskeletal frame rather than integrating with full power armour.

As with much of the armament used by the Space Marines loyal to the Emperor, warriors from the Chaos Space Marines armed with Power Fists are not an uncommon sight.

Some xenos forces are also known to have analogous wargear, and among these are the Eldar. Meanwhile, the Orks use a similar (though much more crude) device known as a Power Klaw which is a servo-motored claw, large even for an Ork, with fearsome bladed fingers and sparking with discharges from an unstable disruptive field. Though more primitive in appearance, it is no less potent and is fully capable of dismembering infantry and tearing apart armoured vehicles. Uniquely, Commissar Yarrick of the Imperial Guard is famous for his Power Klaw, which he tore from a defeated Ork Warboss and adapted for his own use, as much a weapon as a symbol of his prowess in the never-ending war against the Orks.

Variants

Dreadnought Power Fist - The Space Marine Dreadnought's primary close combat weapon has also been known as the Power Fist. Although it operates on the same principle as the infantry Power Fist, it is vastly more powerful -- the internal power generation and size of the cybernetic Dreadnought means there is effectively no limit to the strength of the Power Fist's energy field, making it more effective against heavily-armoured vehicles.

Known variants include:

Astares Power Fist - This is the standard pattern powered gauntlet worn by the Emperor's Adeptus Astartes.
Chainfist - The Chainfist is similar to a Power Fist, but is outfitted with a reduced, powered chainsaw blade. The Chainfist was originally intended for breaching bulkheads on starships and Space Hulks but it is equally adept at tearing up vehicles on a planetside battlefield. Most Space Marine Terminators are equipped with a Storm Bolter and Power Fist. Occasionally, the Chainfist will substitute for a Power Fist if the situation calls for a cutting edge.
Tang War Pattern Power Fist - These compact, slim-fitting gauntlets are lighter and smaller than the standard designs issued to Imperial Space Marine officers. Though they are not considered unique, they are by no means common in the Imperial armed forces either.
Lightning Claw - This formidable weapon consists of a powered gauntlet, fitted with three or four sharpened blades. A matter-disrupting energy field is projected around the blades, allowing them to cut through armour and flesh with minimal effort. Lightning Claws are almost invariably worn as a pair by Space Marines or Chaos Space Marines who prefer melee combat. Lightning Claws are a more specialized weapon than Power Fists, as they are extremely effective against enemy infantry but have little impact on heavily-armoured vehicles.
Mezoa Pattern Power Fist - Rather than encasing an edged weapon with a power field, a Power Fist uses the energy to disrupt material in a more violent fashion. Worn as a huge glove, when the mechanically augmented fist strikes its target it can tear open even the heaviest armour and burst flesh into a shower of blood and tissue. Unless worn as part of a suit of Power Armour, a Power Fist normally requires heavy backpack-mounted power sources connected to the fist via heavy cables. The Mezoa Pattern specialises in an oversized mantle to increase punching power, and suitably braced the user can knock through the strongest bulkheads. Most are ancient relics, with the mantle inscribed with family heraldry or iconography indicating impressive victories.
Midath Pattern Power Glove - The Forge World of Midath is a lingering enigma for the Adeptus Mechanicus of theCalixis Sector. Some of the Lathe Worlds' earliest records speak of Midath as a grand Forge World, capable of building superheavy vehicles, voidships, and even Titan components. Such a Forge World would be a wondrous boon to the Calixis Sector, if only it could be found. The Forge World has been "missing" for as long as anyone can remember, to the point where some question whether it was ever real in the first place. There are many arguments for and against the existence of Midath, but one of the strongest proofs is an exceptionally rare melee weapon known as the Midath Pattern Power Glove. Consisting of a single sheath that extends all the way to the shoulder, the flexible golden material that makes up most of the glove is of a substance unknown to the Mechanicus. It bends and flexes without resistance, and never crinkles or ruffles, maintaining its smooth, reflective surface at all times. Once active, the glove acts much like a standard Power Fist, albeit a low-powered one, but as the power field surrounds the entire length of the user's arm it can be used to parry quite effectively. Unfortunately, it is this same power field that tends to cause damage to the human nervous system the longer the glove is activated, limiting its use in extended combat actions. Those who have studied the Midath Pattern Power Fist determined that each glove was made to order, matching the specifications of their user in every way. Who these weapons once belonged to will likely never be known, and most of the remaining Power Fists sit in the private collections of high-ranking Calixian nobles.
Titan Powerfist - Titan-sized Powerfists are massive versions of the standard infantry Powerfist used by Imperial Battle Titans. They encompass an entire category of weapons that employ a Titan's prodigous strength and size to smash and tear apart the enemy. They are horrendously effective against enemy Titans and other war engines -- if the Titan can get close enough to use them. They can only be mounted on the Titan's arms, which rules out their use by Warhound -class Scout Titans, and are ineffective on the massive Imperator-class Battle Titans.

Other Races

The Orks use a variant of the Power Fist known as aPower Klaw, which is a large claw, often with three bladed fingers. The wielders of such weapons can easily rip apart armour of any kind.
The Eldar Striking Scorpion Exarchs employ a variant called a Scorpion's Claw, which integrates a Shuriken Catapult with a Power Fist, and is shaped like the claw of a scorpion.

Notable Power Fists

Gauntlets of ultramar — One of the *Gauntlets of Ultramar*

Gauntlets of Ultramar - The Gauntlets of Ultramar are an ancient pair of Power Fists, accompanied by a set of ornate shoulder plates (compatible with both Artificer Power Armour and Terminator Armour) and a set of built-in Bolters. Their true origin is unknown, all that is known is that they were taken back from a fell Champion of Chaos by the Primarch Roboute Guilliman of the Ultramarines. Only the Chapter Master of the Ultramarines, currently Lord Macragge Marneus Calgar, is permitted to wear them into combat.