1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS 3A 174:2012AEROSPACE SERIES100 Countersunk head,D-slot recess,corrosion-resisting steelbolts (Unified threads),Strength Class 880 MPa, foraircraftPublishing and copyright info
2、rmationThe BSI copyright notice displayed in this document indicates when the documentwas last issued. The British Standards Institution 2012Published by BSI Standards Limited 2012ISBN 978 0 580 78754 6ICS 49.030.20The following BSI references relate to the work on this standard:Committee reference
3、ACE/12Draft for comment 12/30261969 DCPublication historyFirst published 1956Second edition May 1962Third (present) edition November 2012Amendments issued since publicationDate Text affectedBS 3A 174:2012 BRITISH STANDARDContentsForeword ii1 Scope 12 Normative references 13 General 14 Material and m
4、anufacture 15 Dimensions 26 Screw threads 27 Protective finish 28 Hardness values 29 Identification and marking 210 Inspection procedure 3AnnexesAnnex A (informative) Principles of flushness control and recommended gaugingpractice 12List of figuresFigure 1 Basic dimensions 3Figure 2 Diagram (part) s
5、howing maximum and minimum head conditions 5Figure 3 Bearing length, clamping length and overall length dimensions 5Figure A.1 Method of measurement of head protrusion 14Figure A.2 Protrusion gauge block (see Figure A.1 and subclause A.9) 15List of tablesTable 1 Materials for manufacture of bolts 2T
6、able 2 Dimensions 4Table 3 Bearing length L, clamping length M and overall length E6Table A.1 Protrusion gauge block dimensions 15Summary of pagesThis document comprises a front cover, an inside front cover, pages i to ii,pages 1 to 16, an inside back cover and a back cover.BRITISH STANDARD BS 3A 17
7、4:2012 The British Standards Institution 2012 iForewordPublishing informationThis British Standard is published by BSI Standards Limited, under licence fromThe British Standards Institution, and came into effect on 30 November 2012. Itwas prepared by Technical Committee ACE/12, Aerospace fasteners a
8、ndfastening systems. A list of organizations represented on this committee can beobtained on request to its secretary.SupersessionThis British Standard supersedes BS 2A 174:1962, which is withdrawn.Information about this documentThis revision of BS A 174 includes the addition of high expansion heat-
9、resistingsteel to BS HR 650, BS EN 2398 and BS EN 2399 and changes to take account ofthe mechanical properties of these steels. In addition, the revision introduces apart number code for bolts made from high expansion heat-resisting steels, todistinguish them from bolts made from the BS S 80 materia
10、l. This code will alsobe marked on the bolt surface see Clause 9.Presentational conventionsThe provisions of this standard are presented in roman (i.e. upright) type. Itsrequirements are expressed in sentences in which the principal auxiliary verb is“shall”.Commentary, explanation and general inform
11、ative material is presented insmaller italic type, and does not constitute a normative element.Contractual and legal considerationsThis publication does not purport to include all the necessary provisions of acontract. Users are responsible for its correct application.Compliance with a British Stand
12、ard cannot confer immunity from legalobligations.BRITISH STANDARDBS 3A 174:2012ii The British Standards Institution 20121 ScopeThis British Standard specifies the materials, dimensions and inspectionrequirements for D-slot recess, corrosion-resisting steel bolts with100 countersunk heads and unified
13、 threads for aircraft(Strength Class 880 MPa).2 Normative referencesThe following documents, in whole or in part, are normatively referenced in thisdocument and are indispensable for its application. For dated references, onlythe edition cited applies. For undated references, the latest edition of t
14、hereferenced document (including any amendments) applies.BS S 80, High chromium-nickel corrosion resisting steel forging stock, bars,forgings and parts (880 to 1 080 MPa: limiting ruling section 100 mm)BS 4A 100:2003, Specification for general requirements for bolts and freerunning nuts of tensile s
15、trength not exceeding 1 249 MPaBS HR 650, Specification for high expansion heat-resisting steel bar and wire forthe manufacture of bolts, studs, set screws and nuts (Ni 25.5, Cr 15, Ti 2, Mn 1.5,Mo 1.25, Si 0.7, V 0.3) (Limiting ruling section 50 mm)BS EN 2398, Aerospace series Heat resisting steel
16、FE-PA2601(X6NiCrTiMoV26-15) Rm 900 MPa Bars for machined bolts D 25 mmBS EN 2399, Aerospace series Heat resisting steel FE-PA2601(X4NiCrTiMoV26-15) Rm 900 MPa Bars for forged bolts D 25 mm3 GeneralThe bolts shall conform to the relevant requirements of BS 4A 100:2003 inrespect of manufacture, screw
17、threads and identification and marking.4 Material and manufacture4.1 The bolts shall be manufactured by one of the following methods:a) machined from bright drawn bars which conform to one of theBritish Standards specified in Table 1;b) forged from material which conforms to one of the British Stand
18、ardsspecified in Table 1.4.2 The materials used for the manufacture of forged bolts shall have thefollowing mechanical properties in the finally heat treated condition:a) 0.2% proof stress (min.): 590 MPa;b) tensile stress (min.): 880 MPa;c) elongation (min.): 12%;d) Izod impact (min.): 55 J (40 ft.
19、lbf). Not applicable to the materials given inBS HR 650, BS EN 2398 and BS EN 2399.BRITISH STANDARD BS 3A 174:2012 The British Standards Institution 2012 1Table 1 Materials for manufacture of boltsBS No. Material ApplicationBSS80 212% nickel-chromium-molybdenum steel For the manufacture of machined
20、boltsBS HR 650 High expansion heat-resisting steel For the manufacture of forged boltsBS EN 2398 High expansion heat-resisting steel For the manufacture of machined boltsBS EN 2399 High expansion heat-resisting steel For the manufacture of forged bolts5 Dimensions5.1 All finished bolts shall conform
21、 to the dimensions and tolerances given inFigure 1, Figure 2 and Table 2.5.2 The clamping length of the bolt shall conform to the dimensions andtolerances given in Table 3, and shall be such that, when a standard nut withoutcountersink or a ring gauge without countersink has been screwed on as far a
22、spossible by hand, its leading face is within the distance M from the uppersurface of the bolt head. The runout of thread shall not exceed twice the pitch.5.3 The nominal length of the bolt shall be the minimum bearing length L,which is determined by the minimum clamping length M, less two threadpit
23、ches. See Figure 3.6 Screw threadsThe bolts shall have unified threads of the form and class of fit specified in therelevant requirements of BS 4A 100:2003, Clause 8.7 Protective finishNone.8 Hardness valuesThe hardness values of finished bolts shall be as follows:a) for machined components:255 min.
24、/321 max. HB or 270 min./340 max. HV;b) for forged components:248 min./341 max. HB or 260 min./360 max. HV.9 Identification and marking9.1 IdentificationThe British Standard identifier and part number (in accordance with Table 3)shall not be applied to the bolts, but shall be clearly marked on label
25、s of parcelsof bolts together with the batch identification code.NOTE For example, A174-11D is a bolt with thread size 10-32 UNF and bearinglength 1.1 inches manufactured in BS S 80 material and A174X11D is a bolt the samesize manufactured in BS EN 2398 or BS EN 2399 material.BRITISH STANDARDBS 3A 1
26、74:20122 The British Standards Institution 20129.2 MarkingBolts manufactured in BS HR 650, BS EN 2398 and BS EN 2399 material shall bemarked with an “X” in accordance with BS 4A 100:2003, Clause 8.10 Inspection procedureThe bolts shall be inspected in accordance with the relevant requirements ofBS 4
27、A 100:2003.NOTE The requirements for gauging head dimensions are given in A.8.Figure 1 Basic dimensionsa) Basic dimensions b) Details of slotc) Enlarged view of headBRITISH STANDARD BS 3A 174:2012 The British Standards Institution 2012 3Table 2 Dimensions (1 of 2)1 2 3456789 10Decimalequivalentof no
28、minalthread sizeNominalthreadsizeDiameter of plainportion of shankAThreadrunout(2 pitch)Min.lengthofscrewedportionofshankA)FDiameter of head NominalheaddepthDB)(Forreferenceonly)To sharp cornersV(For reference only)AbsoluteminimumBmax. min. min. ref. max. min.in in in in in in in in in0.164-32UNC8-3
29、2 UNC 0.163 5 0.160 5 0.063 0.327 0.334 0.323 0.287 0.0680.190-32UNF10-32UNF0.189 5 0.186 5 0.063 0.377 0.387 0.375 0.337 0.0800.250-28UNF14-28UNF0.249 5 0.246 5 0.071 0.459 0.510 0.496 0.452 0.1060.312 5-24UNF5/16-24UNF0.312 0 0.309 0 0.083 0.497 0.638 0.622 0.572 0.1330.375-24UNF3/8-24UNF0.374 5 0
30、.371 5 0.083 0.597 0.766 0.748 0.692 0.1590.437 5-20UNF7/16-20UNF0.437 0 0.433 5 0.100 0.670 0.894 0.874 0.812 0.1860.500-20UNF12 -20UNF0.499 5 0.496 0 0.100 0.770 1.022 1.000 0.932 0.213Table 2 Dimensions (2 of 2)2 1 12 13 14 1516171819202122NominalthreadsizeGaug-ingdia.NHead protrusionRadius under
31、bolt headRDepth ofchamferGSlotProtrusion abovegauging dia.PFlush-nesstolerance(P max. P min.)WidthHDepthJRad.Umax. min. max. min. max. min. min. max.00.0100.010in in in in in in in in in in in in8-32 UNC 0.267 1 0.027 6 0.023 8 0.003 8 0.020 0.010 0.030 0.020 0.045 0.054 0.045 0.21910-32UNF0.314 7 0
32、.029 9 0.025 9 0.004 0 0.020 0.010 0.030 0.020 0.050 0.060 0.060 0.21914-28 UNF 0.424 5 0.035 3 0.030 7 0.004 6 0.030 0.015 0.040 0.030 0.050 0.060 0.068 0.3005/16-24UNF0.538 9 0.040 9 0.035 7 0.005 2 0.030 0.015 0.040 0.030 0.050 0.060 0.087 0.3003/8-24UNF0.653 2 0.046 6 0.040 7 0.005 9 0.030 0.015
33、 0.040 0.030 0.070 0.080 0.123 0.3757/16-20UNF0.767 6 0.052 2 0.045 7 0.006 5 0.030 0.015 0.050 0.040 0.070 0.080 0.134 0.37512-20 UNF 0.882 0 0.057 8 0.050 7 0.007 1 0.030 0.015 0.050 0.040 0.070 0.080 0.134 0.375A)This dimension is an absolute minimum associated with maximum length M and minimum l
34、ength E.Itisnotintended that it be used for manufacturing or inspection purposes.B)These dimensions have been calculated as the mean between maximum and minimum head depth, correspondingto maximum and minimum diameters to sharp corners, the head angle and shank diameter being taken asnominal.BRITISH
35、 STANDARDBS 3A 174:20124 The British Standards Institution 2012Figure 2 Diagram (part) showing maximum and minimum head conditionsNOTE Gauges suitable for controlling flushness are described in Annex A.The limits on head protrusion do not permit the extreme limits on diameter to sharp corners and on
36、 head angleshown by (1) and (2) to occur in one and the same head. This is because the application of these countersunkheads demands a high degree of flushness.(1) Indicates the maximum head protrusion obtainable with the minimum head angle.(2) Indicates the minimum head protrusion obtainable with t
37、he maximum head angle.Figure 3 Bearing length, clamping length and overall length dimensionsBRITISH STANDARD BS 3A 174:2012 The British Standards Institution 2012 5Table 3 Bearing length L, clamping length M and overall length E (1 of 6)No. 8-32 UNC No. 10-32 UNFPart No. L minA)M00.030E+0.0400Part N
38、o. L minA)M00.030E+0.0400in in in in in in1C 0.1 0.193 0.55 1D 0.1 0.193 0.602C 0.2 0.293 0.65 2D 0.2 0.293 0.703C 0.3 0.393 0.75 3D 0.3 0.393 0.804C 0.4 0.493 0.85 4D 0.4 0.493 0.905C 0.5 0.593 0.95 5D 0.5 0.593 1.006C 0.6 0.693 1.05 6D 0.6 0.693 1.107C 0.7 0.793 1.15 7D 0.7 0.793 1.208C 0.8 0.893
39、1.25 8D 0.8 0.893 1.309C 0.9 0.993 1.35 9D 0.9 0.993 1.4010C 1.0 1.093 1.45 10D 1.0 1.093 1.5011C 1.1 1.193 1.55 11D 1.1 1.193 1.6012C 1.2 1.293 1.65 12D 1.2 1.293 1.7013C 1.3 1.393 1.75 13D 1.3 1.393 1.8014C 1.4 1.493 1.85 14D 1.4 1.493 1.9015C 1.5 1.593 1.95 15D 1.5 1.593 2.0016C 1.6 1.693 2.05 16
40、D 1.6 1.693 2.1017C 1.7 1.793 2.15 17D 1.7 1.793 2.2018C 1.8 1.893 2.25 18D 1.8 1.893 2.3019C 1.9 1.993 2.35 19D 1.9 1.993 2.4020C 2.0 2.093 2.45 20D 2.0 2.093 2.5021C 2.1 2.193 2.55 21D 2.1 2.193 2.6022C 2.2 2.293 2.65 22D 2.2 2.293 2.7023C 2.3 2.393 2.75 23D 2.3 2.393 2.8024C 2.4 2.493 2.85 24D 2.
41、4 2.493 2.9025C 2.5 2.593 2.95 25D 2.5 2.593 3.0026C 2.6 2.693 3.05 26D 2.6 2.693 3.1027C 2.7 2.793 3.15 27D 2.7 2.793 3.2028C 2.8 2.893 3.25 28D 2.8 2.893 3.30BRITISH STANDARDBS 3A 174:20126 The British Standards Institution 2012Table 3 Bearing length L, clamping length M and overall length E (2 of
42、 6)No. 8-32 UNC No. 10-32 UNFPart No. L minA)M00.030E+0.0400Part No. L minA)M00.030E+0.0400in in in in in in29C 2.9 2.993 3.35 29D 2.9 2.993 3.4030C 3.0 3.093 3.45 30D 3.0 3.093 3.5031C 3.1 3.193 3.55 31D 3.1 3.193 3.6032C 3.2 3.293 3.65 32D 3.2 3.293 3.7033C 3.3 3.393 3.75 33D 3.3 3.393 3.8034C 3.4
43、 3.493 3.85 34D 3.4 3.493 3.9035C 3.5 3.593 3.95 35D 3.5 3.593 4.0036C 3.6 3.693 4.05 36D 3.6 3.693 4.1037C 3.7 3.793 4.15 37D 3.7 3.793 4.2038C 3.8 3.893 4.25 38D 3.8 3.893 4.3039C 3.9 3.993 4.35 39D 3.9 3.993 4.4040C 4.0 4.093 4.45 40D 4.0 4.093 4.5041C 4.1 4.193 4.55 41D 4.1 4.193 4.6042C 4.2 4.2
44、93 4.65 42D 4.2 4.293 4.7043C 4.3 4.393 4.75 43D 4.3 4.393 4.8044C 4.4 4.493 4.85 44D 4.4 4.493 4.9045C 4.5 4.593 4.95 45D 4.5 4.593 5.0046C 4.6 4.693 5.05 46D 4.6 4.693 5.1047C 4.7 4.793 5.15 47D 4.7 4.793 5.2048C 4.8 4.893 5.25 48D 4.8 4.893 5.3049C 4.9 4.993 5.35 49D 4.9 4.993 5.4050C 5.0 5.093 5
45、.45 50D 5.0 5.093 5.5051C 5.1 5.193 5.55 51D 5.1 5.193 5.6052C 5.2 5.293 5.65 52D 5.2 5.293 5.7053C 5.3 5.393 5.75 53D 5.3 5.393 5.80BRITISH STANDARD BS 3A 174:2012 The British Standards Institution 2012 7Table 3 Bearing length L, clamping length M and overall length E (3 of 6)14 in UNF5/16in UNF3/8
46、in UNFPartNo.LminA)M00.030E+0.0400PartNo.LminA)M00.030E+0.0400PartNo.L minA)M00.030E+0.0400in in in in in in in in in2E 0.2 0.301 0.80 2G 0.2 0.313 0.85 2J 0.2 0.313 0.953E 0.3 0.401 0.90 3G 0.3 0.413 0.95 3J 0.3 0.413 1.054E 0.4 0.501 1.00 4G 0.4 0.513 1.05 4J 0.4 0.513 1.155E 0.5 0.601 1.10 5G 0.5
47、 0.613 1.15 5J 0.5 0.613 1.256E 0.6 0.701 1.20 6G 0.6 0.713 1.25 6J 0.6 0.713 1.357E 0.7 0.801 1.30 7G 0.7 0.813 1.35 7J 0.7 0.813 1.458E 0.8 0.901 1.40 8G 0.8 0.913 1.45 8J 0.8 0.913 1.559E 0.9 1.001 1.50 9G 0.9 1.013 1.55 9J 0.9 1.013 1.6510E 1.0 1.101 1.60 10G 1.0 1.113 1.65 10J 1.0 1.113 1.7511E
48、 1.1 1.201 1.70 11G 1.1 1.213 1.75 11J 1.1 1.213 1.8512E 1.2 1.301 1.80 12G 1.2 1.313 1.85 12J 1.2 1.313 1.9513E 1.3 1.401 1.90 13G 1.3 1.413 1.95 13J 1.3 1.413 2.0514E 1.4 1.501 2.00 14G 1.4 1.513 2.05 14J 1.4 1.513 2.1515E 1.5 1.601 2.10 15G 1.5 1.613 2.15 15J 1.5 1.613 2.2516E 1.6 1.701 2.20 16G
49、1.6 1.713 2.25 16J 1.6 1.713 2.3517E 1.7 1.801 2.30 17G 1.7 1.813 2.35 17J 1.7 1.813 2.4518E 1.8 1.901 2.40 18G 1.8 1.913 2.45 18J 1.8 1.913 2.5519E 1.9 2.001 2.50 19G 1.9 2.013 2.55 19J 1.9 2.013 2.6520E 2.0 2.101 2.60 20G 2.0 2.113 2.65 20J 2.0 2.113 2.7521E 2.1 2.201 2.70 21G 2.1 2.213 2.75 21J 2.1 2.213 2.8522E 2.2 2.301 2.80 22G 2.2 2.313 2.85 22J 2.2 2.313 2.9523E 2.3 2.401 2.90 23G 2.3 2.413 2.95 23J 2.3 2.413 3.0524E 2.4 2.501 3.00 24G 2.4 2.513 3.05 24J 2.4 2.513 3.1525E 2.5 2.601 3.10 25G
