ASME B18.5 pdf download Round Head Bolts (Inch Series)
2.4.3 Straightness. The length of any permissible swell on the body under the head or neck of bolts shall be excluded from checks for shank straightness. A sug- gested gage and a gaging procedure for checking straightness are shown in ASME B18.2.9.
2.5 Threads Uncoated threads shall be Unified coarse (UNC or UNRC Series), Class 2A, in accordance with ASME B1.1. Coated threads shall be accepted based on3A highlimits and 2A low limits. Unless otherwise specified, gaging for screw thread dimensional acceptability shall be in accordance with Gaging System 21 as specified in ASME B1.3M.
2.6 Length of Thread
2.6.1 Measurement. The length of thread shall be measured, parallel to the axis of the bolt, from the end of the bolt to the last complete (full form) thread.
2.6.2 Minimum Thread Length. The minimum length of thread shall be equal to twice the basic bolt diameter plus 0.25 in. for nominal bolt lengths of 6 in. or shorter, and twice the basic bolt diameter plus 0.50 in. for longer nominal lengths.
3 Bolts of nominal lengths too short to accommodate the minimum thread lengths shall be threaded for full length. The length from the head or neck to the first complete (full form) thread shall not exceed the length of 2 1 ⁄ 2 threads for sizes up to and including 1 in., and 3 1 ⁄ 2 threads for sizes over 1 in. 2.7 Points Bolts need not be pointed.
2.8 Materials and Mechanical Properties
2.8.1 Steel. Unless otherwise specified, chemical and mechanical properties of steel bolts, except step bolts and elevator bolts, shall conform to Grade A of ASTM A 307, and shall be stress relieved as required by the Standard. Due to peculiarities of the head configura- tions, steel step bolts and elevator bolts are considered conforming if the tensile strength in pounds is equal to or greater than the values indicated in the applicable material standard.
2.8.2 Other Materials. Nonferrous materials are covered in ASTM F 468. Corrosion-resistant steels are covered in ASTM F 593.
2.9 Identification Symbols
2.9.1 Grade Symbols. Each ofthe products included in this Standard shall be marked in accordance with the requirements of the applicable specification for its chemistry and mechanical properties.
2.9.2 Source Symbols. Each of the products included in this Standard shall be marked to identify the source accepting responsibility for the conformance of the bolt to this and other applicable specifications.
2.10 Finish Unless otherwise specified, round head bolts shall be supplied with natural (as processed) finish, unplated or uncoated.
2.11 Workmanship Bolts shall be free from surface imperfections such as burrs, seams, laps, loose scale, and other surface irregu- larities that could affect serviceability. When engineering requirements of the application require control of surface discontinuities, the purchaser shall specify conformance to ASTM F 788/F 788M in the original inquiry and purchase order.
2.12 Dimensional Conformance
(a) Unless otherwise specified, the following desig- nated characteristics shall be inspected to the inspection levels shown according to ASME B18.18.2, and shall be within specified limits.
b) If a documented, verifiable, statistically based in- process inspection system is used by the fastener manu- facturer, inspections may be conducted at any point after which that characteristic will not be altered. Inspection sample sizes and reporting shall be in accordance with recognized quality systems such as ASME, ASTM, and ISO.
(c) For nondesignated characteristics, the provisions of ASME B18.18.1 shall apply.