ASME B18.6.2:2020 pdf free download

ASME B18.6.2:2020 pdf free download.Square Head Set Screws and Slotted Headless Set Screws.
2.1.3 Head True Position. The axis of the head shall belocated at true position within a tolerance zone having adiameter equal to 6% of the specified maximum width
across flats of the head, relative to the axis of thescrew shank,regardless of feature size. For refereepurposes, the evaluation shall be made by holding thebody in a collet or chuck one bolt diameter from
under the head and rotating the part. With the indicatorin line with the axis ofthe bolt or screw.find and record thelowest point on each flat or the highest point on each lobe.The true position is one-half of the largest absolute differ-ence between the high and low values for any opposing setof flats or lobes.
2.2 Length
2.2.1 Measurement.The length of square head setscrews shall be measured parallel to the axis of thescrew from the intersection of the side of the headwith the undersurface to the extreme point.
2.2.2 Length Tolerance. The length tolerance forsquare head set screws shall be as shown in Table 2.2.2-1.
2.3 Threads
2.3.1 Thread Series and Class.The threads on squarehead set screws shall be Unified Inch coarse, fine, or 8-thread series, Class 2A, in accordance with ASME B1.1.For threads with additive finish. the size limits of Class2A apply before coating and the thread after coating issubject to acceptance using a basic Class 3A size Gothread gage and a Class 2A thread gage for eitherminimum material or NO Go.
2.3.2 Thread Gaging. Unless otherwise specified,dimensional acceptability of screw threads shall be deter-mined based on System 21,ASME B1.3.
2.4 Thread Length
Square head set screws shall have complete (full-form)threads extending over the portion of the screw lengththat is not affected by the point. For the respective constructions,threads shall extend into the neck relief,to the conical underside of the head, or within onethread (as measured with a thread ring gage) from theflat underside of the head. Threads through angular orcrowned portions of points shall have fully formedroots with partial crests. Because standard threadgages provide only for lengths of engagement up toiztimes the basic screw diameter, changes in pitchdiameter of either or both the external and internalthread may be required for applications involvinglonger lengths of engagement.
2.5 Points
2.5.1 Point Types. When unspecified, square head setscrews shall be supplied with cup points. Cup points maybe knurled (internally or externally) at the manufacturer’soption. Specifications for cone,dog. half-dog.flat, and ovalpoints are in Table 2.5.1-1.
2.5.2 Point Angles.The external point angles specifiedshall apply only to the portions of the point that lie belowthe thread root diameter, as angles within the threadprofile may vary due to manufacturing processes.
2.5.3 Dog Points.When the length of usable (effectiveJthread is less than the basic screw diameter, dog pointsshall not be used.Half-dog points shall be used for suchscrew lengths.
2.5.3.1 Point True Position. The axis of the dog orhalf-dog points shall be at true position with respect tothe axis of the thread within a tolerance zone having adiameter of 0.010 in. for sizes up to and including/[0.750) in. and a diameter of 0.020 in. for larger sizes,regardless of feature size.
2.6 Material
When a material is not specified,square head set screwsshall be made from case-hardened steel or through-hardened steel at the option of the manufacturer.
2.6.1 Case-Hardened Steel. Unless otherwise speci-fied, case-hardened steel square head set screws shallbe low carbon steel, case-hardened to 83 HR15Nminimum, with the following case depth.