ASIMLE B18.8.2-2000 pdf download

ASIMLE B18.8.2-2000 pdf download.TAPER PINS, DOWEL PINS, STRAIGHT PINS, GROOVED PINS, AND SPRING PINS (INGH SERIES).
4.1.2 Roundness. The outer periphery of hardened ground production dowel pins shall conform to true round about the longitudinal axis of pin within 0.0001 in., when measured with equipment that will detect a lobed surface.
4.2 Ends
The ends of hardened ground production dowel pins shall be reasonably flat and perpendicular to the axis of pin. The corners at both ends of pins shall be rounded as defined in Table 3 and the accompanying figure.
4.3 Length
4.3.1 Measurement. The length of hardened ground production dowel pins shall he measured overall from end to end, parallel to the axis of pin.
4.3.2 Tolerance on Length. The tolerance on the length of hardened ground production dowel pins shall be ±0.010 in.
4.3.3 Preferred Lengths. The preferred sizes and lengths in which hardened ground production dowel pins are normally available are depicted in Table 3A. Other sizes and lengths are produced as required by the purchaser.
4.3.4 Straightness. Production dowel pins shall he straight over that portion of the pin length not affected by the rounded ends within an accumulative total of 0.0005 in. per inch of length for nominal lengths, up to and including 4 in., and within 0.002 in. total for all nominal lengths over 4 in.
4.4 Surface Roughness
The surface roughness on hardened ground production dowel pins shall not exceed 8 microinch (pin.) (arithmetical average) over the cylindrical portion of the pin length nor 125 microinch (ilin) (arithmetical average) on all other surfaces. Refer to ASME B46.l. For pins having additive finishes, these limits shall apply prior to coating or plating.
4.5 Material and Heat Treatment
4.5.1 Steel. Hardened ground production dowel pins shall be made from carbon steel having a sulphur and phosphorus content not in excess of 0.05 and 0.04 percent, respectively.
4.5.2 Heat Treatment. Pins shall be case hardened to a minimum total case depth of 0.0 10 in. for nominal pin sizes 54 in., or smaller. and 0.02 in. for nominal pin sizes /,6 in., and larger. Pins shall be quenched in oil from the austenizing temperature and tempered to provide a minimum case hardness of Rockwell C58, or equivalent, and a core hardness of Rockwell C50 to 55. The microstructure shall be tempered martensite.
4.6 Finishes
Unless otherwise specified, production dowel pins shall be furnished with a ground (as processed) finish. unplated or uncoated. Protective or decorative finishes. where required, shall he subject to agreement between the manufacturer and purchaser. However, where a finish applied to pins is such that it might produce hydrogen embrittlement, the pins shall be baked for a suitable time at a temperature that will obviate such embrittlement. Baking shall he accomplished as soon as possible following the plating or coating operation inasmuch as delay is detrimental to achieving the desired results. Where additive-type finishes are used, the tabulated dimensions and tolerances shall apply to the pins prior to application of the plating or coating, unless otherwise specified by the purchaser.
4.7 Workmanship
Dowel pins shall be free from burrs, cracks, seams. scratches, and nicks, and any other defects affecting their serviceability.
4.8 Application Information
4.8.1 Hole Sizes. Because of the wide variety of materials in which dowel pins are used and the many design requirements which must he considered, it is riot possible to provide hole size recommendations that will be suitable for all applications. However, the suggested hole sizes tabulated at the end of this subparagraph have been commonly used for press-fitting production dowel pins into materials such as mild steels and cast iron. In soft materials such as aluminum or zinc die castings, hole size limits are usually decreased by 0.0005 in. to increase the press fit.
5.1.2 Roundness. The outer periphery of unhardened ground dowel pins shall conform to true round
about the longitudinal axis of pin within 0.00025 in.