ASME B18.2.1-2012 pdf download

ASME B18.2.1-2012 pdf download.Square, Hex, Heavy Hex, and Askew Head Bolts and Hex, Heavy Hex, Hex Flange, Lobed Head, and Lag Screws (Inch Series).
2.12 Grade and Manufacturer’s Identification
2.12.1 Identification Symbols. Identification marking symbols on products included in this Standard shall be raised or indented at the manufacturer’s option unless otherwise specified. Markings shall be legible to the unaided eye with the exception of corrective lenses. When raised, the height of the marking may not exceed 0.015 in. over the specified maximum head height for bolts 5/ in. and smaller. For bolts larger than % in., the marking may not project more than 0.030 in. over the specified maximum head height. When indented, the depth of the marking shall not reduce the load-carrying capacity of the fastener.
2.12.2 Grade Symbols. Each of the products included in this Standard shall be marked in accordance with the requirements of the applicable specification for its material, mechanical, or performance requirements.
2.12.3 Source Symbols. Each of the products included in this Standard shall be marked in accordance with the requirements of the applicable specification for its material, mechanical, or performance requirements to identify its source, manufacturer, or private label distributor.
2.13 Quality Assurance
Unless otherwise specified, manufacturers shall pro‘ide bolts and screws in accordance with ASME B18.18, Category 2 for dimensions, plus the products shall comply with all of the requirements of the material standard referenced in the purchaser’s product designation (see para. 2.11).
3 BOLTS
Square head, hex, heavy hex, and askew head bolts are presented in Tables 1 through 4, respectively.
3.1 Surface Condition
Bolts need not be finished on any surface except threads.
3.2 Head Taper
Maximum width across flats and corners shall not be exceeded. No transverse section through the head between 25% and 75% of actual head height, as measured from the bearing surface, shall be less than the minimum across flats and corners requirements. (This is not applicable to askew head bolts.)
3.3 Bearing Surface
A die scam across the bearing surface of bolts is permissible. Bearing surface shall be perpendicular to the axis of the body within a tolerance of 3 deg for 1-in. size and smaller, and 2 deg for sizes larger than 1 in. Angularity and head height measurement shall be taken removed. Upon completion of the machining, all geometric requirements specified for the bearing surface and head height shall be met. For askew head bolts, see Note (1) in Table 4.
3.4 Body Diameter
Any swell or fin under the head or any die seam on the body shall not exceed the basic bolt diameter by more than the following, unless otherwise agreed to between purchaser and supplier:
(a) 0.030 in. for sizes up through 4z in.
(‘b) 0.050 in. for sizes over 1/2 in. through 3/4 in.
(c) 0.060 in. for sizes over 3/4 in. through 1’/2in.
(d) 0.090 in. for sizes over 11/2 in.
The diameter of the unthreaded length on bolts that are threaded for full length shall not be less than the minimum pitch diameter of the thread nor greater than the maximum body diameter, E, max., specified in Tables 1 through 4.
3.5 Reduced Diameter Body
When specified by the purchaser, bolts may be supplied in the reduced diameter body style. These shall have a body diameter of not less than the minimum pitch diameter of the thread and not exceeding the minimum body diameter, E, miii., shown in Tables I through 4. Any swell or fin under the head or any die seam on the body shall not exceed E, mm. by more than the following, unless otherwise agreed to between the purchaser and the supplier:
(a) 0.030 in. for sizes up through 1/2 in.
(‘N 0.050 in. for sizes over in. through 3/4 in.
(c) 0.060 in. for sizes over 3/4 in. through 1’/2 in.
(d) 0.090 in. for sizes over 11/2 in.
3.6 Length Tolerance
Bolt length tolerances are given in Table 5.
3.7 Thread Length
Nominal thread length, L7, is a reference dimension intended for calculation purposes only. Lr equals twice the basic thread diameter +0.25 in. for nominal bolt lengths up to and including 6 in., and twice the basic thread diameter +0.50 in. for nominal lengths over 6 in.
The length of thread on bolts shall be controlled by the grip gaging length, LG. The maximum grip gaging length, LG, max., as calculated and rounded to two decimal places for any bolt not threaded full length, shall be equal to the nominal bolt length, L, nom., minus LT (LG, max. pL, nom. — LT) with a tolerance of minus a length equal to five coarse thread pitches.