ASME B18.2.3.9M pdf free download

ASME B18.2.3.9M pdf free download METRIC HEAVY HEX FLANGE SCREWS
20.2 Body Length, L s Body length, L s , on long screws that are not threaded full length is the distance, parallel to the axis ofthe screw, from the plane of the bearing circle to the last scratch of thread or top of the extrusion angle, whichever is closer to the head. For standard diameter-length combinations of screws, the values for L s minimum are specified in Table 9. For diameter-length combinations not listed in Table 9, the minimum body length on long screws that are not threaded full length is equal to the maximum grip length, as determined above, minus the reference transition thread length, (X), as specified in Table 10: L s minimum p L g maximum − (X).
20.3 Thread Length, (B) The thread length, (B), specified in Table 10, is a reference dimension intended for calculation purposes only, and is the distance, parallel to the axis of the screw, from the extreme end of the screw to the last complete (full-form) thread.
20.4 Transition Thread Length, (X) The transition thread length, (X), specified in Table 10, is a reference dimension intended for calculation purposes only. It includes the length of incomplete threads and tolerances on grip length and body length. The transition from full-form thread to incomplete thread shall be smooth and uniform. The major diameter of the incomplete threads shall not exceed the actual major diameter of the complete (full-form) threads. 9 The transition threads shall have a rounded root contour.
21 MATERIALS AND MECHANICAL PROPERTIES
21.1 Steel Unless otherwise specified, steel screws shall conform to the requirements for Property Class 9.8 (8.8 for size M20) or Property Class 10.9 as specified in ASTM F 568M, or SAE J1199.
21.2 Corrosion-Resistant Steels Unless otherwise specified, corrosion-resistant steel screws shall conform to the requirements of ASTM F 738M.
21.3 Nonferrous Metals Unless otherwise specified, nonferrous screws shall conform to the requirements of ASTM F 468M.
22 IDENTIFICATION SYMBOLS Markings shall be raised or recessed on the top of the head or raised on the top of the flange unless otherwise specified by the purchaser. Markings shall be legible to the unaided eye with the exception of corrective lenses. When raised, markings shall project not less than 0.1 mm for M14 and smaller screws, and 0.3 mm for M16 and M20 screws, above the top surface of the head or flange; and total head height (head plus markings) shall not exceed the specified maximum head height, K maximum, plus 0.1 mm for M5 and M6 screws, 0.2 mm for M8 and M10 screws, 0.3 mm for M12 and M14 screws, and 0.4 mm for M16 and M20 screws.
22.1 Property Class Symbols Each screw shall be marked in accordance with the requirements of the applicable specification for its material and mechanical properties.
22.2 Source Symbols Each screw shall be marked to identify its source (manufacturer or private label distributor).
23 FINISH Unless otherwise specified, screws shall be supplied with a natural (as processed) finish, unplated or un- coated, in a clean condition, and lightly oiled. 24 WORKMANSHIP Screws shall be free from surface imperfections such as burrs, seams, laps, loose scale, and other surface irregularities that could affect serviceability and shall conform to ASTM F 788/F 788M.
25 INSPECTION AND QUALITY ASSURANCE Unless otherwise specified, acceptability of screws shall be determined in accordance with ASME B18.18.1M.
26 DIMENSIONAL CONFORMANCE Products shall conform to the specified dimensions. Unless otherwise specified, the following provisions shall apply for inspection of dimensional characteristics:
(a) Unless otherwise specified, the following desig- nated dimensional characteristics shall be inspected to the inspection levels shown according to ASME B18.18.2M.
If verifiable in-process inspection is used, inspection sample sizes and reporting shall be in accordance with the applicable ASME, ASTM, or SAE quality system consensus standard.
(b) For nondesignated dimensional characteristics, the provisionsofASMEB18.18.1Mshallapply.Shouldanon- designateddimensionbedeterminedtobeoutsideitsspecified limits, itshall be deemed conforming to this Standard if the user, who is the installer, accepts the dimension, based on form, fit, and function considerations.
27 CLEARANCE HOLES The recommended sizes of clearance holes in material to be assembled using heavy hex flange screws are the normal series given in ASME B18.2.8.