An asymmetrical structure for an open-end wrench is disclosed. The force-applying surface of the wrench facing the opening is mainly set as an arc surface, and the force-receiving surface of the wrench facing the opening is set as a flat surface. When a nut is engaged in the opening of the wrench, one side of the nut abuts against the force-receiving surface, and the other side is in contact with the force-applying point on the arc surface of the force-applying surface. When the wrench is turned, the force of the torque can only be transmitted through the force point contacting the nut, thereby preventing the force of the torque from being dispersed.

An asymmetrical structure for an open-end wrench is disclosed. The force-applying surface of the wrench facing the opening is mainly set as an arc surface, and the force-receiving surface of the wrench facing the opening is set as a flat surface. When a nut is engaged in the opening of the wrench, one side of the nut abuts against the force-receiving surface, and the other side is in contact with the force-applying point on the arc surface of the force-applying surface. When the wrench is turned, the force of the torque can only be transmitted through the force point contacting the nut, thereby preventing the force of the torque from being dispersed.

Disclosed are aspects of exemplars of torque-limiting devices, methods and mechanisms exemplars methods may include placing an actuator in a tool containment interface of a handle; movable mounting a tool portion with an actuation catch and a work piece engaging region (WER) in the interface; applying sufficient force to the movable mounting to the handle may be via pins, guides and slots. Said catch may be one of a body catch and a lever catch; and, the actuator terminates on one of a ball shaped end that forms and interface with the body catch and a force lever that forms an interface with the lever catch.

Disclosed are aspects of exemplars of torque-limiting devices, methods and mechanisms exemplars methods may include placing an actuator in a tool containment interface of a handle; movable mounting a tool portion with an actuation catch and a work piece engaging region (WER) in the interface; applying sufficient force to the movable mounting to the handle may be via pins, guides and slots. Said catch may be one of a body catch and a lever catch; and, the actuator terminates on one of a ball shaped end that forms and interface with the body catch and a force lever that forms an interface with the lever catch.

A torque structure includes a first body, a second body, a first elastic member, a third body, and a limit unit. The second body is provided with a second receiving chamber, a first pivot portion, at least one first positioning portion and at least one second positioning portion. The first elastic member is received in the second receiving chamber. The third body is provided with a drive portion, a pivot seat, a second pivot portion, and a first limit portion. The limit unit is assembled with the second body and the third body and rotated between a disengaging position where the third body is unlocked from the second body and has a torque slip function relative to the second body, and a engaging position where the third body is locked by the second body and does not have a torque slip function.

A two-way nut spanner has a handle and an engaging head having a base, a first engaging portion and a second engaging portion. The base has a first abutting surface and a second abutting surface respectively located on two opposite sides of the base. The first engaging portion protrudes from the first abutting surface of the base and has multiple first engaging blocks. Each of the engaging blocks has a first inclined surface. The second engaging portion protrudes from the second abutting surface of the base and has a second engaging block having a second inclined surface. The engaging head has the first engaging portion and the second engaging portion with different engaging structures to enhance convenience for using the two-way nut spanner.

A two-way nut spanner has a handle and an engaging head having a base, a first engaging portion and a second engaging portion. The base has a first abutting surface and a second abutting surface respectively located on two opposite sides of the base. The first engaging portion protrudes from the first abutting surface of the base and has multiple first engaging blocks. Each of the engaging blocks has a first inclined surface. The second engaging portion protrudes from the second abutting surface of the base and has a second engaging block having a second inclined surface. The engaging head has the first engaging portion and the second engaging portion with different engaging structures to enhance convenience for using the two-way nut spanner.

A screwing tool, including an elongate handle which, at each of the two ends thereof, bears a head pivotable about a pivot axis and having two torque transmission flanks in each case and has a force application flank for introducing a force in order to produce a torque on the head remote from the relevant force application flank, wherein, in a pivoting end position of the head, in which a stop of the head lies against a counter stop of the handle, a narrow side of the head functionally directed away from the stop forms an extension of the force application flank. The second head forms an extension of the force application flank and can be used as a hand grip.

A screwing tool, including an elongate handle which, at each of the two ends thereof, bears a head pivotable about a pivot axis and having two torque transmission flanks in each case and has a force application flank for introducing a force in order to produce a torque on the head remote from the relevant force application flank, wherein, in a pivoting end position of the head, in which a stop of the head lies against a counter stop of the handle, a narrow side of the head functionally directed away from the stop forms an extension of the force application flank. The second head forms an extension of the force application flank and can be used as a hand grip.

A pneumatic hammer extender arm assembly is provided comprising an elongated extender arm body defining a hammer engaging portion formed at a first end of the body, and a hammerhead engaging portion formed at a second end of the body. A hammerhead is detachably engageable to the hammerhead engaging portion to allow for quick change of the hammerhead without the need for any tools. The hammerhead may alternately be implemented to engage and apply an impact force to a fastener that may be axially offset from the extender arm body.