ASME B107.300:2021 pdf free download – 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 controlthe tightness of threaded fasteners. It also providesperformance and safety requirements for manually oper-ated electronic torque instruments with integral or inter-changeable heads. lt includes requirements forendurance, torque value ranges, angle measurements,and accuracy for these torque instruments. It furtherprovides performance and safety requirements for elec-tronic torque testers used for checking manually operated,hand-held torque wrenches and torque screwdrivers.It isnot intended to describe products infrequently utilized orthose designed for special purposes.
This Standard may be used as a guide by state autho-rities or other regulatory bodies in the formulation of lawsor regulations. It is also intended for voluntary use byestablishments that use or manufacture the instrumentscovered.
2 DEFINITIONS
accuracy: the permissible deviation,tolerance,or errorband.A higher value means a lower certainty of correct-ness.
angle: the amount of axial rotational displacement from astart point to an end point.
break-over: a temporary reduction in torque indicating atarget 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 targetvalue has been achieved, indicated by a displacement ofthe handle of less than 5 deg.
first peak: the maximum torque value just prior to thetorque drop-off, which on Category 14, Types ll and lvtorque wrenches occurs as the wrench begins its momen-tary reduction in torque.
flex-head: see flexible ratchet head.
flexible ratchet head: a handle with the capability of oper-ating at an angle other than perpendicular to the axis ofrotation.
full scale: see rated capacity.
graduation: a mark on the instrument indicating a torquevalue.
hand torque instrument: a tool combining hand wrenchingand torque measurement functions, formerly referred toas hand torque wrench.
increment: the value of the difference between adjacentgraduations.
indicated value: for Category 14,Type I, the value theinstrument displays when torque is applied; for Typesl1,I1I, and lv, the value to which the instrument is setor preset.
measured value: the actual torque determined by a torquetester.
operating load: the operating load shall be calculated bydividing the rated capacity by the distance between theaxis of the torque moment and the center of the grip ordesignated load point.
peak: the maximum torque value reached during theprocess of applying the load to the wrench.
pivot: a short rod or shaft on which a related part rotates orswings.
rated capacity: the maximum intended torque the usershall measure or apply.
resolution: the smallest distinguishable change indisplayed value.
scale: the representation of the range of the instrument,divided into increments marked by numbered andunnumbered graduations.
setting: the amount of torque the instrumentis expected toapply.
torque-to-angle: a method of assembly where a thresholdtorque is applied and then more torque is applied toproduce a specific angle.
track: continuous readout of torque applied at anymoment.
usable range of the transducer: the range to which theaccuracy requirements of para. 5.9 are applied.