ASME B89-1-13:2001 pdf download

ASME B89-1-13:2001 pdf download.MICROMETERS
1 SCOPE
This Standard is intended to provide the essential requirements for micrometers as a basis for mutual understanding between manufacturers and consumers. Outside, inside, and depth micrometers are described in the Standard.
2 DEFINITIONS
backlash: a relative movement between interacting mechanical parts, resulting from looseness [ASME B5.54M-1992 (R1998)]. In this Standard, backlash is further defined as the rotation of the spindle, in the opposite direction of the initial reading, before spindle moves in a linear direction. This condition is typically caused by looseness of fit between the lead screw and adjusting nut. bias: systematic error of the indication of a measuring instrument (VIM). eccentricity: the distance between the geometric center or axis of the body and its axis of rotation. end shake: the amount of spindle movement, when an axial force is applied in the direction of the spindle alternating towards the anvil and away from the anvil, without rotating the spindle. error (of indication) of a measuring instrument: indi- cation of a measuring instrument minus a true value of the corresponding quantity (VIM). NOTE: This concept applies mainly where the instrument is compared to a reference standard. flatness: the condition of a surface having all elements in one plane (ASME Y14.5M-1994). maximum permissible error (MPE): extreme values of an error permitted by specifications, etc., for a given measuring instrument (VIM). parallelism: the condition of a surface or center plane, equidistant at all points from a datum plane or axis, equidistant along its length from one or more datum planes or a datum axis (ASME Y14.5M-1994).runout: a composite tolerance used to control the functional relationship of one or more features of a part to a datum axis. The types of features controlled by runout tolerances include those surfaces constructed around a datum axis and those constructed at right angles to a datum axis (ASME Y14.5M-1994). side shake: the amount of spindle side movement, when a force is applied perpendicularly to the measuring end of the spindle, alternating from side to side, without rotating the spindle. tolerance: the total amount the specified dimension is permitted to vary. The tolerance is the difference between the maximum and minimum limits (ASME Y14.5M-1994).
4 MICROMETERS, GENERAL
4.1 Materials The materials used for the component parts of a micrometer shall meet the minimum requirements for hardness, stability, and strength. 4.2 Resolution Micrometers using the inch system shall read to the least count of 0.001 in., 0.0001 in., or 0.00005 in. Micrometers using the metric system shall read to 0.01 mm, 0.002 mm, or 0.001 mm. 4.3 Finish The surface of graduated parts shall have a satin chrome or dull, nonglare finish. All other exposed parts not utilized as measuring components shall be coated to prevent corrosion. Exposed surfaces of measuring components shall have a ground finish with surface roughness not to exceed 32 ?in. (0.8 ?m) Ra, except where otherwise specified within this document. 4.4 Identification Marking In addition to other markings, instruments shall be marked in a permanent and legible manner with the manufacturer’s name or trademark so that the part number, range of the instrument, and the source of the manufacturer can be readily determined. 4.5 Adjustments Each instrument shall be adjustable to compensate for wear on the measuring faces and/or wear between the screw portion of the spindle and the nut. 4.6 Micrometers Screw Spindle The screw spindle material shall be stabilized, preci- sion-ground, and have a hardness not less than 62 on the Rockwell C Scale. The fit between the spindle and its bearings, including the nut, shall be free-turning without perceptible backlash, end shake, or side shake.