1、I.1 37 ,IT; INCH-POUND, IMIL-STD-403C30 June 1992SUPERSEDINGMIL-STD-403B14 June 1968MILITARY STANDARDPREPARATION FOR AND INSTALLATION OFRIVETS AND SCREWS, ROCKET,MISSILE, AND AIRFRAMS STRUCTURESAMSC N/A FSC 1410DISTRIBUTION STATEMENT A. Approved for public release;distribution is unlimited.I.0iIProv
2、ided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-403CFOREWORD1. This military standard is approved for use by allDepartments and Agencies of the Department of Defense.2. Beneficial comments (recommendations, additions,deletions) and any pertinent
3、data which may be of use in improvingthis document should be addressed to: Commander, U.S. Army MissileCommand, ATTN: AMSMI-RD-SE-TD-ST, Redstone Arsenal, AL 35898-5276by using the Standardization Document Improvement Proposal (DDForm1426) appearing at the end of this document or by letter.iiProvide
4、d by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-403CCONTENTSI ParagraphII1.I 1.12.2.1I 2.1.12.23.3.13.23.33.43.53.5.13.5.23.64.4.14.1.1o4.24.2.14.2.2I4.34.44.5 4.5.14.5.1.14.5.24.5.2.14.5.34.5.45.5.15.1.15.1.1.15.1.1.2SCOPEPurposeAPPLICABLE DOCUMENT
5、SGovernment documentsSpecifications, standards, and handbooksOrder of precedenceDEFINITIONSDefinitionsCocked headManufactured headupset head (shop formed)DimplingDraw dimplingModified-radius dimplingCountersinking (machine countersinking)GENERAL REQUIREMENTSHole formationHole sizesDimplingModified-r
6、adius dimplingCracked dimplesCountersinkingCombination dimple and countersinkingfor rivets and screwsCleaning and protective coatingsFinishing sequenceSealingCleaning of mating surfacesRemoval of strippable coatingMaterials which are to be stored afterdrillingGap limitations between joined sheetsDET
7、AILED REQUIREMENTSDimpled holesDimplingDimpling temperaturesHot dimpling precaution!hemically-expanded rivetsHoles for screwsrivets88888.-8.999“.99.999101010101010101010 a7111111111111112131415ivProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-!IIIIII
8、IIIIMIL-STD-403CCONTENTSTable(s) !ZUilEv For 2017-T rivets driven hard 16VI For all rivets except 2017-T rivetsdriven hard 17VII Average nominal projection before driving 18Figure(s). 123.45678Dimple size dimensions for rivetsCountersink dimensions for rivetsCombination dimple and countersinkdimensi
9、ons for rivetsAcceptable and unacceptable conditionsUpset head diameterDimple dimensions for screwsCountersink dimensions for screwsCombination dimple and countersinkdimensions for screwso,II vIa71 -11920212223242526Provided by IHSNot for ResaleNo reproduction or networking permitted without license
10、 from IHS-,-,-MIL-STD-403C1. SCOPE1.1 Purpose. The purpose of this standard is to establishacceptable limitations applicable to preparation for, andinstallation of rivets and screws for rocket, missile and airframestructures.I.otIII,.bi-IProvided by IHSNot for ResaleNo reproduction or networking per
11、mitted without license from IHS-,-,-MIL-STD-403C2. APPLICABLE DOCUNENTS2.1 Government documents.2.1.1 Specifications, standards, and handbooks. Thefollowing specifications, standards, and handbooks form a part ofthis document to the extent specified herein. Unless otherwisespecified, the issues of t
12、hese documents are those listed in theissue of the Department of Defense Index of Specifications andStandards (DODISS) and supplement thereto, cited in thesolicitation (see 6.2). “-SPECIFICATIONMILITARYMIL-P-116 -MIL-S-8802 -MIL-S-1103O -SPECIFICATIONFEDERALTT-P-1757 -STANDARDMILITARYMIL-STD-171 -Pr
13、eservation, Methods ofSealing Compound, Temperature-Resistant, Integral Fuel Tanks andFuel Cell Cavities, High AdhesionSealing Compound, Single Component,Non-Curing, Polysulfide Base.a71Primer Coating, Zinc Chromate, Low-Moisture SensitivityFinishing of Metal and Wood Surfaces(Unless otherwise indic
14、ated, copies of the federal andmilitary specifications, standards, and handbooks are availablefrom the Standardization Documents Order Desk, Bldg. 4D, 700Robbins Ave., Philadelphia, PA 19111-5094.2.2 Order of precedence. In the event of a conflict betweenthe text of this document and the references
15、cited herein, the textof this document takes precedence. Nothing in this document, !2II1Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IIIIIIIIIIIIIIa71 however,specificMIL-STD-403Csupersedes applicable laws and regulations unless aexemption has bee
16、n obtained.IIII .IProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-403C3. DEFINITIONS3.1 Definitions. For the purposes offollowing definitions shall apply.this standard, the3.2 Cocked head. The seating of either the manufactured heador the ups
17、et head at an angle other than perpendicular to the shankof the rivet parallel to the surface.3.3 Manufactured head. The head formed at the time the rivetis manufactured.3.4 Upset head (shop formed). The head formed during theriveting operation.3.5 Dimpling. Stretching a relatively small shallowinde
18、ntation into sheet metal. Stretching metal into a conicalflange for use of a countersunk rivet or screw. Dimpling issubstantially stronger than countersinking and should be performedon relatively thin panels.3.5.1 Draw dimplinq. Dimpling that is produced by utilizinga male and female die without fir
19、st preparing a pilot hole. Thedimple dies punch the hole and form the dimple in a singleoperation. (NOTE - Draw dimpling shall not be permitted withoutwritten approval of the procuring activity.)3.5.2 Modified-radius dimplin. Dimpling which is producedby utilizing a male and female die where the con
20、tour of the diesresults in a dimple with the top and bottom sides of the dimplenon-parallel .3.6 Countersinking (machine countersinking). Chamfering aconical depression around the top of a hole for receiving the headof a fastener.a71I4IProvided by IHSNot for ResaleNo reproduction or networking permi
21、tted without license from IHS-,-,-IIIIII1III1I1,1I.MIL-STD-403C4. GENERAL REQUIREMENTS4.1 Hole formation.4.1.1 Hole sizes. Unless otherwise specified, pilot holesshall be drilled before dimpling. The final hole size shall bedrilled or reamed after dimpling, or countersinking. Holetolerance shall be
22、in accordance with tables I, II, III, or IV.4.2 Dimpling. Where flush applications of rivets and screwsare specified, both sheets to be joined shall be dimpled when eachsheet is within the thickness specified in tables I, II, III, orIV. All parts shall be dimpled separately with the followingexcepti
23、ons:a. Parts cemented together with a total thickness notgreater than the greatest thickness for dimpling.b. Parts, spot or seam welded, with a total thicknessgreater than the greatest thickness for dimpling.4.2.1 Modified-radius dimplinq. Modified-radius dimplingshall be used when dimpling by form
24、countersinking is not possiblewith the following exceptions:a. A modified-radius dimple shall not nest into anothermodified-radius dimple.b. The greatest material thickness for modified-radiusdimpling shall be 0.064 inch.c. The greatest size of modified-radius dimple shall be0.188 inch diameter rive
25、t.4.2.2 Cracked dimples. Cracked dimples shall be rejected.MY repairs shall be subject to engineering approval.4.3 Countersinking. Countersinking shall be used when theouter sheet is within the limits specified in tables I, II, III, orIV, or when dimpling is not permitted by engineering drawings or
26、bythis standard.4.4 Combination dimple and countersinking for rivets andscrews. This method shall be used only when specified on the_ering drawings or when the outer sheet is less than the leastProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-
27、403Cthickness for countersinking and the inner sheet is greater thanthe greatest thickness for dimpling.4.5 Cleaning and protective coatings.4.5.1 Finishing sequence. Parts shall be cleaned (see4.5.2), surface treated or electroplated, and primed in detailprior to assembly as specified on applicable
28、 drawings.4.5.1.1 Sealing. Rivets, buck bolts, blind rivets andthreaded fasteners shall be assembled with wet, unthinned zincchromate primer conforming to TT-P-1757. If the fasteners aredissimilar to and can result in a direct contact with magnesium,washer of 5052 aluminum alloy with not less than a
29、n over-lap of0.125 to 0.25 inch shall be used in addition to TT-P-1757 primer.a71aOther sealing compounds, such as materials conforming to ML-S-11030 and MIL-S-8802, may be used as substitute for TT-P-1757 when sapproved by the procuring activity.4.5.2 Cleaning of mating surfaces. All chips, burrs,
30、andforeign material shall be removed from the mating surfaces prior tosurface treating.4.5.2.1 Removal of strippable coating. The temporarystrippable coatings must be removed from all joints and from underthe heads of all fasteners before installations.4.5.3 Materials to be stored. Materials which a
31、re to bestored after drilling, countersinking, or dimpling prior tofinishing shall be protected against corrosion in accordance withthe applicable methods of MIL-P-116. In cases where drilling,countersinking, or dimpling is accomplished after finishing, thedamaged areas of the protective finish shal
32、l be repaired with asuitable surface treatment meeting the requirements of MIL-STD-171and reprimed.4.5.4 Gap limitations between joined sheets. Gap limitationsbetween joined sheets shall be in accordance with figures 1 and 6and tables I, II, III and IV.6Provided by IHSNot for ResaleNo reproduction o
33、r networking permitted without license from IHS-,-,-t MIL-STD-403C5. DETAILED REQUIREMENTSI5.1 Dimpled holes. When dimpling is performed, pilot holesshall be drilled, the material dimpled, then the hole drilled orreamed to the final size noted in tables I, II, III, OK Iv. Bothsheets to be joined sha
34、ll be dimpled when each sheet is within thethickness limits specified in figures 1 or 6 and tables I, II, III,or IV.5.1.1 Dimpling. Aluminum, magnesium and titanium alloy sheetstock shall be dimpled in accordance with temperature requirementsof 5.1.1.1.5.1.1.1 Dimpling temperatures. The following te
35、mperaturesmust be obtained at the bend radii during the dimple cycle:2024-T3 or T4 Ambient Temperature*6061-T4 Ambient Temperature*6061-T6 Ambient Temperature7075-T6 Not less than 149 Celsius (C) -Not greater than 204C2024-T6 Not less than 149C - Notgreater than 204CMagnesium Not less than 149C - No
36、tgreater than 204CTitanium Not less than 316C - Notgreater than 426C* If cracking occurs, heat to not less than 149C - notgreater than 204”C. Dimpling of 7075-T6, interrupted-aged,material may be done at room temperature with the written approvalof the procuring agency.5.1.1.2 Hot dimpling precautio
37、n. The method of hot dimplingshall be controlled to prevent loss of sheet strength. Whenthermocouple controlled temperature heater blocks are used, theheater blocks shall be tight on the dies at operating temperature.The thermocouple location shall be near the dies and approximatelythe same location
38、 in all heater blocks. Any protective finish orIa717Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-403Ctreatment must be removed around the area contacted by the dimplingtools.5.2 Rivets.5.2.1 Conventional rivets. The application of conventi
39、onalrivets shall be in accordance with table I, unless otherwisespecified on the engineering drawing,5.2.2 Pull-through and self-plugging blind rivets. Pull-through and self-plugginq blind rivets shall be installed as inaccordance with table-ll-and the manufacturers recommendedpractices except as mo
40、dified by the engineering drawing or by thisstandard.5.2.2.1 Acceptable and unacceptable limits of upset heads.Acceptable and unacceptable limits of upset heads shall be as shownin Figure 4. Choice of the proper rivet size and grip length willbe the controlling factor to meet these conditions.5.2.3
41、Chemically expanded rivets. Chemically expanded rivetsshall be installed in accordance with table III and i-hemanufacturers recommended practices except as modified by theengineering drawing or by this standard.5.2.4 Rivet hole tolerance. Unless otherwise specified,holes shall be prepared for rivets
42、 in accordance with thetOleI_aIICes specified in tables 1, II, or III. Oversize holes shallbe corrected by the use of one size larger rivet with the followinqrestrictions :a.pattern shallb.clearance forEdge distanceNot more than 10 percent (%) of the rivets in thebe affected.The least required edge
43、distance and sufficient headthe replacement rivet shall be obtainable. NOTE -is the distance from the center line of the rivet tothe edge of the sheet or joint. This dimension should not be lessthan two times the rivet diameter in sheet stock, three times therivet diameter in non-ferrous castings. G
44、enerally, rivet spacingis called out on all drawings in accordance with stressrequirements.c. The hole shall not have a dimension greater than theallowable diameter for the next larger size rivet.8 Ia71IProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,
45、-IIIIIIIIIIMIL-STD-403Ca71 d. When countersinks are oversize the skin thicknessshall permit the use of the next larger size rivet.5.2,5 Countersinking. Unless otherwise specified on theengineering ersinking sizes and dimensionallimitations shall be in accordance with figure 2 and table I, III,or 111
46、.5.2.6 Combination dimple and countersinking. Combinationdimple and countersinking sizes and dimensional limitations shallbe in accordance with figure 3 and tables I, II, or III. 5.2.7 Rivet heads.5.2.7.1 Manufactured rivet head height. Manufactured headsof countersunk rivets shall not be below the
47、skin of exposed orcritical surfaces either before or after driving. Unless otherwisespecified on the engineering drawing, the projection height ofcountersunk heads shall be not greater than 0.004 inch (see figure1). A maximum of 0.006 inch may be shaved from a protruding headin order to meet this re
48、quirement.5.2.7.2 Cocked heads. Cocking of either head (manufacturedor upset) shall not be allowed, except where one or more joinedsurfaces are anqular. When only one side of the material to be:0” joined is in an-angular positio;, the upset head shall be formed onthe angular side of the material.1I
49、5.2.7.3 Upset heads. The diameter and height of upset headsshall be determined in accordance with figure 5 and table V or VI.II 5.2.7.4 Malformed upset heads. The mean height of malformedupset heads shall be not less than one-third of the rivet-shankI diameter. The mean height shall be within the limits specified inI
