ASME B18.8.2 pdf download.Taper Pins, Dowel Pins,Straight Pins, GroovedPins, and Spring Pins(Inch Series).
4.5 MateriaL and Heat Treatment
4.5.1 SteeL. Hardened ground machine dowel pins shall be made Ironi any carbon or alloy steel capable of being heat treated to a core hardness a Rockwell (:51) mini in LI 01 and having sul fur and phosphorus content not in excess ut 0.05% and 0.04%, respectively.
4.5.2 Heat Treatment. Pins shall be hardened by qtienc-hing in oil from the .iustenizing temperature and tempering to meet the following conditions.
4.5.2.1 Case-Hardened Pins. Pins shall be case hardened to a minimum total case depth of 0.1)10 in. for nominal pin sizes in.. or smaller, and 0.015 in. for nunminal pin sizes in., miid larger. The case shall have a minimum surface hardness of Rockwell C70. or equivalent, amid the core hardness shall be Rockwell C47 to C5H. The microstruture shall he tempered marten’
4.5.2.2 Through-Hardened Pins, At manufacturer’s option, pins smaller than /8 in. nominal size may be through hardened to a hardness of Rockwell (30 to (:58, however, in no instance shall the hardness of the pin surface be softer thami th.it of the core. The microstructure shall 1w tempered martensite.
4.6 Finishes
Unless otherwise specified, machine dowel pins shall he furnished with a ground (as processed) finish or with black o.xide coating at the option of the manufacturer. A lightweight oil may be used to inhibit corrosion during transportation. Other protective or decorative finishes, where required, shall he subject to agreement between the manufacturer and purchaser. however, where a finish applied to carbon or alloy steel pins is such that it might produce hydrogen embrittlernent, the pins shall he baked for a suitable time at a temperature that will obviate such embrittlement. Baking shall be 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 ot’the plating or coating, unless otherwise specified by the purchaser.
4.7 Workmanship
Dowel pins shall he free from detrimental burrs, cracks. seams, or nicks and other defects affecting their serviceability or properties.
4.8 Designation
4.8.1 Hardened ground machine dowel pins shall be designated by the following data, in the sequence shown:
product name (noun first), including pin series; nominal pin diameter (fraction or decimal equivalent): length(fraction or decimal equivalent); material; and protective linish. if required. Sec examples below.
EXAM Pl.ES:
(I) Piii. l1,lrltened Ground Machine — Standard Series, Steel. Phosphaw Coated
(2) Pin. hardened Ground Machine towel — Overiize Series. 0620 2500, Steel
4.9 AppLication Information
4.9.1 Hole Sizes. Because o the wide variety of materials in which dowel pins are used and of the many design requirements which must be considered, it is not possible to provide hole size reconimendations that will be suitable tar all applications. however, the suggested hole sizes in Table 49.1-I have been commonly used for press-fitting standard series machine dowel pins into material 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.
hIOlL’S for oversize series machine dowel pins may best be dewrniined by the user to suit (lie particul,ir applica— (ion.
4.9.2 Design Calculations. For design calculations, the shear strength ut these standard pins should be based on the values listed in para. 4.9.1.
4.9.3 Responsibility for Modification.
ASME B18.8.2 pdf download
