1、Designation: F2437 12Standard Specification forCarbon and Alloy Steel Compressible-Washer-Type DirectTension Indicators for Use with Cap Screws, Bolts, Anchors,and Studs1This standard is issued under the fixed designation F2437; the number immediately following the designation indicates the year ofo
2、riginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification covers the requirements for carbonand al
3、loy steel compressible-washer-type direct tension indi-cators capable of indicating a specified bolt tension in capscrews, bolts, anchors, and studs.1.2 Direct tension indicators in nominal diameter sizes14through 212 in. are covered.1.3 There are two Types of DTIs covered by thisspecification, Type
4、 1 and Type 2.1.3.1 Type 1 DTIs are suitable for comparatively largebearing surfaces.2Type 1 DTIs are available in Grades 55 and105, which differ in the amount of tension they indicate at aprescribed gap (see Table 1).1.3.2 Type 2 DTIs are suitable for comparatively smallerbearing surfaces.3Type 2 D
5、TIs are available in Grades 5 and 8,which differ in the amount of tension they indicate at aprescribed gap (see Table 1).1.4 Direct tension indicators are intended for installationunder a bolt or cap screw head, a hex nut, or against a hardenedwasher or other flat hardened surface.1.5 The following
6、precautionary statement pertains only tothe test method portions, Section 12 and Appendix XI of thisspecification: This standard does not purport to address all ofthe safety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safe
7、ty and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:4A193/A193M Specification for Alloy-Steel and StainlessSteel Bolting for High Temperature or High PressureService and Other Special Purpose ApplicationsA194/A194M
8、 Specification for Carbon and Alloy Steel Nutsfor Bolts for High Pressure or High Temperature Service,or BothA307 Specification for Carbon Steel Bolts and Studs, 60 000PSI Tensile StrengthA325 Specification for Structural Bolts, Steel, Heat Treated,120/105 ksi Minimum Tensile StrengthA354 Specificat
9、ion for Quenched and Tempered Alloy SteelBolts, Studs, and Other Externally Threaded FastenersA449 Specification for Hex Cap Screws, Bolts and Studs,Steel, Heat Treated, 120/105/90 ksi Minimum TensileStrength, General UseA563 Specification for Carbon and Alloy Steel NutsB633 Specification for Electr
10、odeposited Coatings of Zinc onIron and SteelB695 Specification for Coatings of Zinc Mechanically De-posited on Iron and SteelF436 Specification for Hardened Steel WashersF606 Test Methods for Determining the Mechanical Proper-ties of Externally and Internally Threaded Fasteners,Washers, Direct Tensi
11、on Indicators, and RivetsF1470 Practice for Fastener Sampling for Specified Me-chanical Properties and Performance InspectionF1554 Specification for Anchor Bolts, Steel, 36, 55, and105-ksi Yield StrengthF1941 Specification for Electrodeposited Coatings onThreaded Fasteners (Unified Inch Screw Thread
12、s (UN/UNR)1This specification is under the jurisdiction of ASTM Committee F16 onFasteners and is the direct responsibility of Subcommittee F16.02 on Steel Bolts,Nuts, Rivets and Washers.Current edition approved April 1, 2012. Published November 2012. Originallyapproved in 2006. Last previous edition
13、 approved in 2011 as F243711. DOI:10.1520/F2437-12.2Examples of a comparatively large bearing surface would include heavy hexbolts, heavy hex nuts, and so forth.3Examples of a comparatively small bearing surface would include a hex capscrew, hex nut, and so forth.4For referenced ASTM standards, visi
14、t the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 10
15、0 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12.2 ASME Standards:5ASME B18.2.1 Square and Hex Bolts and Screws, InchSeriesASME B18.2.8 Clearance Holes for Bolts Screws, and Studs2.3 SAE Standard:6SAE J429 Mechanical and Material Requirements for Exter-nally Thread
16、ed FastenersSAE J995 Mechanical and Material Requirements for SteelNuts3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 compressible-washer-type direct tension indicator,na washer-type element inserted under the cap screw or bolthead, hex nut, or hardened washer, having the cap
17、ability ofindicating the achievement of a required bolt tension by thedegree of direct tension indicator plastic deformation. Hereaf-ter referred to as direct tension indicator or DTI. Alternatively,DTIs are commonly referred to as load-indicating washers ortension-indicating washers.4. Ordering Inf
18、ormation4.1 Orders for direct tension indicators under this specifica-tion shall include the following:4.1.1 Quantity (number of pieces);4.1.2 Name of product (direct tension indicator);4.1.3 Size, that is, nominal diameter;4.1.4 ASTM designation and year of issue (if not specified,current issue sha
19、ll be used);4.1.5 Type and Grade:4.1.5.1 Type 1Either Grade 55 or Grade 105,4.1.5.2 Type 2Either Grade 5 or Grade 8;4.1.6 Finish or coating type, if required (5.4);4.1.7 Source inspection, if required (Section 13);4.1.8 Certificates of Compliance, Certificates ofConformance, or Certified Test Report
20、s, if required (Section15); and4.1.9 Any special requirements, including those for load-gap curves or other special test data, as well as intended bolt,anchor, or stud tension, if known.4.2 Recommended FastenersFasteners meeting the re-quirements of the Standards referenced in Table 1 are consid-ere
21、d compatible with the DTI type(s) listed.75. Materials and Manufacture5.1 Direct tension indicators shall have a configurationproduced by extrusion, punching, pressing, or similar formingto permit a measurable decrease in thickness when placed incompression.5.2 The design shall be such that the degr
22、ee of plasticdeformation of the protrusions shall indicate the tension in atightened cap screw, bolt, anchor, or stud.5.3 Heat TreatmentThe process used for heat treatment ofDTIs, if required, shall be through-hardening by heating to atemperature above the upper transformation temperature,5Available
23、 from American Society of Mechanical Engineers (ASME), ASMEInternational Headquarters, Three Park Ave., New York, NY 10016-5990, http:/www.asme.org.6Available from Society of Automotive Engineers (SAE), 400 CommonwealthDr., Warrendale, PA 15096-0001, http:/www.sae.org.7Coating or plating of previous
24、ly tested DTIs requires retesting. See 10.3.TABLE 1 Acceptable Range of Compression LoadADTINominalDiameter(in.)Mean Compression LoadBRangein Pounds (lbs)Mean Compression LoadCRangein Pounds (lbs)Grade 5 Grade 8 Grade 55 Grade 10514 2200 to 2450 3100 to 3450 . . . . . .516 3500 to 3850 4950 to 5500
25、. . . . . .38 5300 to 5850 7500 to 8300 . . . . . .716 7200 to 7900 10 100 to 11 200 . . . . . .12 9700 to 10 700 13 700 to 15 340 4450 to 4900 8500 to 9400916 12 350 to 13 600 17 400 to 19 200 5700 to 6300 10 900 to 12 05058 15 550 to 17 200 21 850 to 24 200 7050 to 7800 13 500 to 15 00034 22 600 t
26、o 25 000 31 900 to 35 300 10 500 to 11 600 20 000 to 22 15078 30 850 to 34 100 43 550 to 48 100 14 500 to 16 000 27 650 to 30 5501 40 200 to 44 400 56 700 to 62 700 19 000 to 21 000 36 250 to 40 100118 45, 100 to 49 850 73 150 to 80 900 23 950 to 26 450 47 300 to 52 300114 56 550 to 62 550 91 750 to
27、 101 450 30 400 to 33 600 59 850 to 66 150138 69 350 to 79 750 112 450 to 124 250 38 550 to 42 600 73 800 to 81 600112 83 350 to 92 150 135 150 to 149 400 44 050 to 48 700 89 300 to 98 700158 . . . . . . 55 800 to 61 700 106 200 to 117 400134 121 850 to 134 650 177 850 to 196 500 59 550 to 65 850 12
28、4 600 to 137 750178 154 550 to 170 800 206 050 to 227 750 75 550 to 83 500 144 500 to 159 7002 160 050 to 177 200 236 850 to 261 750 78 650 to 86 950 165 800 to 183 300214 208 400 to 230 350 277 900 to 307 100 102 050 to 112 750 212 900 to 235 350212 256 500 to 283 500 379 600 to 419 600 125 400 to
29、138 600 240 550 to 265 850ACompression load requirements establish the capability of the direct tension indicators to satisfy typical tension requirements for these grades. The user is not obligedto install fasteners and DTIs to these tensions, and is free to specify installation to lower tension va
30、lues. When so specified, the DTI supplier shall provide a load-gap curvein accordance with 15.2 to enable the user to select the appropriate gap criteria for the intended target tension of the application.BMean compression load values for Grades 5 and 8 are based upon 75 % of the proof load for SAE
31、J429 cap screws.CMean compression load values for Grades 55 and 105 are based upon 60 % of the yield strength for the matching fasteners on which they are used.F2437 122quenching in oil, and then tempering by reheating to a suitabletemperature to attain desired mechanical/performance proper-ties.5.4
32、 Protective Coatings or Platings:5.4.1 Unless otherwise specified, the direct tension indica-tors shall be furnished “plain” with the “as-fabricated” surfacefinish without protective coatings.5.4.2 When “plated” is specified, the direct tension indica-tors shall be processed in accordance with the r
33、equirements ofSpecifications B633, B695,orF1941 for the class and type offinish specified.5.4.3 Direct tension indicator manufacturers are free to offerother coatings, platings, or finishes when specified. However,application of any such coating, plating, or finish shall not beundertaken without the
34、 approval of the direct tension indicatormanufacturer.5.5 All direct tension indicators shall have circumferentialindentations spaced equally around the outside circumference,corresponding to and in alignment with each space between theprotrusions. Indentations shall be clearly visible but not solar
35、ge as to interfere with the function of the direct tensionindicator (see Fig. 1).5.5.1 The circumferential indentations indicate where feelergages, if used, are to be inserted during installation inspections,and further make it visually obvious that a direct tensionindicator (rather than a flat wash
36、er) has been used in theassembly.6. Chemical Composition6.1 The direct tension indicators shall conform in chemicalcomposition to the limits given in Table 2.6.2 Product analysis may be made by the purchaser fromfinished direct tension indicators representing each lot. Thechemical composition shall
37、conform to the requirements givenin Table 3.7. Performance Requirements7.1 Compression LoadWhen compressed to the specifiedgap, the compression load shall conform to the requirementsspecified in Table 1.7.2 Hardness:7.2.1 Type 1 DTIs shall have a hardness not less thanHRB70 nor more than HRC22.7.2.2
38、 Type 2 DTIs shall have a hardness not less thanHRB80 nor more than HRC35.8. Dimensions8.1 Type 1 (Grades 55 and 105) and Type 2 (Grades 5 and8) direct tension indicators shall conform to the dimensionsspecified in Table 4.9. Workmanship, Finish, and Appearance9.1 The direct tension indicators shall
39、 be commerciallysmooth and free of injurious material or manufacturing defectsthat would affect their performance.10. Number of Tests and Retests10.1 Responsibility:10.1.1 The direct tension indicator manufacturer shall in-spect each lot of direct tension indicators prior to shipment inaccordance wi
40、th the quality assurance procedures described in10.2.10.1.2 The purpose of a lot inspection testing program is toensure that each lot conforms to the requirements of thisspecification. For such a plan to be fully effective, it is essentialthat the purchaser continue to maintain the identification an
41、dintegrity of each lot following delivery until the product isinstalled in its service application.NOTE 1Contour of protrusions will vary from manufacturer tomanufacturer. The example shown is illustrative.FIG. 1 Direct Tension Indicator Inside Diameter (I.D.) Outside Di-ameter (O.D.) and Protrusion
42、 Bearing Diameter (PBD)TABLE 2 Chemical Composition RequirementsA,BElementComposition, %HeatAnalysisProductAnalysisCarbon 0.30 to 0.50 0.27 to 0.53Manganese 0.50 to 0.90 0.47 to 0.93Phosphorus, max 0.035 0.043Sulfur, max 0.040 0.048Silicon 0.15 to 0.35 0.13 to 0.37ASteel is considered to be alloy by
43、 the American Iron and Steel Institute when themaximum of the range given for the content of alloying elements exceeds one ormore of the following limits: manganese, 1.65 %; silicone, 0.60 %; copper, 0.60 %;or in which a definite range or definite maximum quantity of any of the followingelements is
44、specified or required within the limits of the recognized field ofconstructional alloy steels: aluminum, chromium up to 3.99 %, cobalt, columbium,molybdenum, nickel, titanium, tungsten, vanadium, zirconium, or any other alloy-ing elements added to obtain a desired alloying effect.BSuitable materials
45、 for weathering steel DTIs include the chemistries for Type 3products listed in Specifications A325 and F436.F2437 12310.2 Lot Method:10.2.1 All direct tension indicators shall be processed inaccordance with a lot identification control-quality assuranceplan. The manufacturer shall identify and main
46、tain the integrityof each lot of direct tension indicators from raw materialselection through all processing operations and treatments tofinal packing and shipment. Each lot shall be assigned its ownlot-identification number, each lot shall be tested, and theinspection test reports for each lot shal
47、l be retained.10.2.2 For purposes of assigning an identification numberand from which test samples shall be selected, a lot shallconsist of all direct tension indicators processed essentiallytogether through all operations to placing in the shippingcontainer that are of the same nominal size, produc
48、ed from thesame mill heat of steel, heat-treated in the same heat-treatmentcycle, and of the same finish.10.2.3 The minimum number of samples to be tested todetermine compression loads and coating thickness (whenapplicable) shall be in accordance with the requirementsspecified in Guide F1470.10.3 Nu
49、mber of Tests After AlterationsIf direct tensionindicators are heat-treated, coated, or plated, or otherwisealtered by a subcontractor or manufacturer subsequent totesting, they shall be re-tested in accordance with 10.2 prior toshipment to the purchaser after all alterations have beencompleted.11. Specimen Preparation11.1 Direct tension indicators selected for tests shall betested full size “as-received” without any special preparation.12. Test Methods12.1 Compression load tests shall be conducted in accor-dance with Test Methods F606, with the speci
