ASME B107.300-2010 pdf download

ASME B107.300-2010 pdf download.Torque Instruments.
3 REFERENCES The following documents form a part of this Standard to the extent specified herein. The latest edition shall be used. ASME B107.4, Driving and Spindle Ends for Portable Hand, Impact,Air,and Electric Tools (PercussionTools Excluded) ASME B107.10, Handles and Attachments for Hand Socket Wrenches ASME B107.29, Electronic Tester, Hand Torque Tools Publisher: The American Society of Mechanical Engineers (ASME), Three Park Avenue, New York, NY 10016-5990; Order Department: 22 Law Drive, Box 2300, Fairfield, NJ 07007-2300 (www.asme.org) Guide to Hand Tools — Selection, Safety Tips, Proper Use and Care Publisher: Hand Tools Institute (HTI), 25 North Broadway, Tarrytown, NY 10591 (www.hti.org) 4 DEFINITIONS accuracy: the permissible deviation, tolerance, or error band. A higher value means a lower certainty of correctness. full scale: see rated capacity. graduation: a mark on the instrument indicating a torque value. hand torque instrument: tool combining hand wrenching and torque measurement functions, formerly referred to as “hand torque wrench.” increment: the value of the difference between adjacent graduations. indicated value: for Type I, the value the instrument dis- plays when torque is applied; for Types II and III, the value to which the instrument is set or preset. measured value: the actual torque determined by a torque tester. operating load: the operating load shall be calculated by dividing the rated capacity by the distance between the axis of the torque moment and the center of the grip or designated load point. rated capacity: for graduated instruments, the maximum graduated torque value, also known as full scale; for nongraduated instruments, the maximum manufac- turer-specified torque. scale: the representation of the range of the instrument, divided into increments marked by numbered and unnumbered graduations. setting: the amount of torque the instrument is expected to apply.
5 REQUIREMENTS Figures 1 through 20 are descriptive and not restric- tive. They are not intended to preclude the manufacture or purchase of other forms of torque instruments con- forming to this Standard. Torque Instruments shall pass all applicable tests in section 6. 5.1 Design 5.1.1 Type I, Classes A, B, C, and D — Indicating (a) Operation. Instruments shall indicate torque applied through a deflectingmember. They shall operate in both clockwise and counterclockwise directions. (1) TypeI, Classes A andB —DeflectingBeam. Flexing of a cantilever beam connecting the square drive and the hand grip shall provide the basis ofoperation. Type I, Class A deflecting beam torque instruments may be sim- ilar to that shown in Fig. 1. Type I, Class B deflecting beam torque instruments may be similar to that shown in Fig. 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 which 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 instru- ments may be similar to that shown in Fig. 3. Type I, Class D rigid housing torque instruments may be similar to that shown in Fig. 4.
(b) Indicator. A dial or scale shall be located to permit convenient and accurate reading. The graduation marks shall be colored and shaped to be distinct and easily read. The width of the graduation mark shall not be greater than one-half the adjacent space width. The width of the pointer tip or indicator line shall not be greater than the widest graduation mark, nor shall the pointer completely cover any graduation mark on the outer scale. The pointer shall be located close to the scale face so as to meet the parallax error requirements of para 6.2. (c) Hand Position. If, in order to achieve the required accuracy, it is necessary to apply the load at a specific point on the hand grip, the hand grip shall be pivoted at that point. (d) Auxiliary Functions. Additional features may be incorporated on the torque instrument to improve accu- racy or usefulness. The inclusion of such features shall not be cause for rejection of the torque instrument pro- viding it conforms to the performance requirements of this Standard. (e) Type I, Classes A, B, C, and D, Style 1 — Plain Scale. No auxiliary operational features are required. (f) Type I, Classes A, B, C, and D, Style 2 — Scale With Signal Mechanism. A signal mechanism capable ofbeing adjusted without the use of tools to any graduated value of the instrument shall be provided. The signal shall operate automatically within the accuracy requirements of this Standard.