ASME SA312:2013 pdf download Standard Specification for Pressure Vessel Plates, Alloy Steel, Manganese- Molybdenum and Manganese-Molybdenum-Nickel
4.5.4 When no preference is specified, the suppliermay furnish either a hot-dip zinc coating in accordancewith Specification F 2329,or a mechanically depositedzinc coating in accordance with Specification B 695,Class55.Threaded components (bolts and nuts) shall be coatedby the same zinc-coating process and the supplier’s optionis limited to one process per item with no mixed processesin a lot.
5. Chemical Composition
5.1Grade A and B bolts and studs shall have a heatanalysis conforming to the requirements specified inTable 1 based on the steel producer’s heat analysis.
5.2The purchaser shall have the option of conductingproduct analyses on finished bolts in each lot, which shallconform to the product analysis specified in Table 1.5.3In case of conflict or for referee purposes，theproduct analysis shall take precedence.
5.4 Bolts and studs are customarily furnished fromstock，in which case individual heats of steel cannot beidentified.
5.5Application of heats of steel to which bismuth,selenium, tellurium,or lead has been intentionally adldedshall not be permitted for Grade B bolts and studs.
5.6Chemical analyses shall be performed in accor-dance with Test Methods，Practices， and TerminologyA 751.
6. Mechanical Properties
6.1Grades A and B bolts and studs shall conform tothe hardness specified in Table 2.
6.2Grade A and B bolts and studs 1! in. in diameteror less，other than those excepted in 6.4,shall be testedfull size and shall conform to the requirements for tensilestrength specified in Table 3.
6.3Grade A and B bolts and studs larger than 1/ in.in diameter, other than those excepted in 6.4, shall prefera-bly be tested full size and when equipment of sufficientcapacity is available and shall conform to the requirementsfor tensile strength specified in Table 3. When equipmentof sufficient capacity for full-size bolt testing is not avail-able, or when the length of the bolt makes full-size testingimpractical, machined specimens shall be tested and shallconform to the requirements specified in Table 4.
6.4Grades A and B bolts and studs less than threediameters in length or bolts with drilled or undersize headsare not subject to tensile tests.
6.5In the event that bolts are tested by both full sizeand by machine test specimen methods, the full-size test shall govern if a controversy between the two methodsexists.
6.6For bolts and studs on which both hardness andtension tests are performed， acceptance based on tensilerequirements shall take precedence in the event that thereis controversy over low readings of hardness tests.
7. Dimensions
7.1Unless otherwise specified,threads shall be theCoarse Thread Series as specified in the latest issue ofASME B1.1,and shall have a Class 2A tolerance.
7.2 Unless otherwise specified,Grade A bolts shall behex bolts with dimensions as given in the latest issue ofASME B18.2.1.Unless otherwise specified, Grade B boltsshall be heavy hex bolts with dimensions as given in thelatest issue of ASME B18.2.1.
7.3 Unless otherwise specified,bolts and studs to beused with nuts or tapped holes which have been tappedoversize，in accordance with Specification A 563，shallhave Class 2A threads before hot-dip or mechanicallydeposited zinc coating. After zinc coating the maximumlimit of pitch and major diameter shall not exceed the Class2A maximum limit by more than the following amounts:
Diameter,in.
Ovcrsize Limit, in (mmyo
‘4
0.016
5116-31s
0.017
八i6p’i2
0.018
i6oto 35s， incl
0.020
/s
0.022
1.0 to 1 ‘i4. incl
0.024
13/g. l ‘lr
0.027
i 4to 4.0,incl
0.050
Thcse valucs are the samc as the overtapping required for zinc-coatednuts in Specification A 563.
7.4The gaging limit for bolts and studs shall be verifiedduring manufacture or use by assembly of a nut tapped asnearly as practical to the amount oversize shown above.ln case of dispute, a calibrated thread ring gage of thatsame size (Class x tolerance，gage tolerance plus) shallbe used.Assembly of the gage, or the nut described above,must be possible with hand effort following application oflight machine oil to prevent galling and damage to thegage. These inspections，when performed to resolve dis-putes，shall be performed at the frequency and qualitydescribed in Table 5.
8.Number of Tests and Retests
8.1The requirements of this specification shall be metin continuous mass production for stock, and the manufac-turer shall make sample inspections to ensure that the prod-uct conforms to the specified requirements.Additional tests
ASME SA312:2013 pdf download
