ASME B107.300-2021 pdf free.Hand Torque Tools and Torque Testers.
1 SCOPE This Standard provides performance and safety re- quirements for manually operated torque instruments, commonly used for measurement of torque to control the tightness of threaded fasteners. It also provides performance and safety requirements for manually oper- ated electronic torque instruments with integral or inter- changeable heads. It includes requirements for endurance, torque value ranges, angle measurements, and accuracy for these torque instruments. It further provides performance and safety requirements for elec- tronictorquetestersusedforcheckingmanuallyoperated, hand-held torque wrenches and torque screwdrivers. Itis notintended to describe products infrequentlyutilized or those designed for special purposes. This Standard may be used as a guide by state autho- rities orotherregulatorybodies intheformulationoflaws or regulations. It is also intended for voluntary use by establishments that use or manufacture the instruments covered.
2 DEFINITIONS accuracy: the permissible deviation, tolerance, or error band. A higher value means a lower certainty of correct- ness. angle: the amount ofaxial rotational displacement from a start point to an end point. break-over: a temporary reduction in torque indicating a target value has been achieved, indicated by a displace- ment of the handle of at least 10 deg. click: a temporary reduction in torque indicating a target value has been achieved, indicated by a displacement of the handle of less than 5 deg. first peak: the maximum torque value just prior to the torque drop-off, which on Category 14, Types II and IV torque wrenches occurs as the wrench begins its momen- tary reduction in torque. flex-head: see flexible ratchet head. flexible ratchethead: a handle with the capability ofoper- ating at an angle other than perpendicular to the axis of rotation. full scale: see rated capacity. graduation: a mark on the instrument indicating a torque value.
5.1 Design — Category 14 Mechanical 5.1.1 Type I, Classes A, B, C, and D — Indicating (a) Operation. Instruments shall indicate torque applied through a deflecting member. They shall operate in both clockwise and counterclockwise direc- tions. (1) TypeI, ClassesAandB—DeflectingBeam. Flexing ofacantileverbeam connectingthe square driveandhand grip shall provide the basis of operation. Type I, Class A deflectingbeamtorque instruments maybesimilarto that shown in Figure 5.1.1-1. Type I, Class B deflecting beam torqueinstruments maybesimilarto thatshowninFigure 5.1.1-2. (2) Type I, Classes C and D — Rigid Housing. The deflecting member and dial mechanism shall be enclosed within the rigid housing. The pointer and dial face shall be protected by a transparent cover that shall be so located and constructed as to be reasonably free from accidental damage resulting from being struck or abraded. Type I, Class C rigid housing torque instruments may be similar to that shown in Figure 5.1.1-3. Type I, Class D rigid housing torque instruments may be similar to that shown in Figure 5.1.1-4. (3) Type I, Classes B and D — Interchangeable Head Connection forAdaptersandExtensions.ASME B107.300 pdf download.