1、 CHECK THE MASTER LISTVERIFY THAT THIS IS THE CORRECT VERSION BEFORE USE at https:/repository.msfc.nasa.gov/docs/multiprogram/MSFC-STD-557.pdf MSFC-STD-557 National Aeronautics and REVISION: B Space Administration EFFECTIVE DATE: February 15, 2012 George C. Marshall Space Flight Center Marshall Spac
2、e Flight Center, Alabama 35812 EM20 MSFC TECHNICAL STANDARD THREADED FASTENERS, TITANIUM ALLOYS, USAGE CRITERIA FOR LAUNCH VEHICLES AND SPACECRAFT APPLICATIONS MEASUREMENT SYSTEM INCH-POUND Approved for Public Release; Distribution Unlimited Provided by IHSNot for ResaleNo reproduction or networking
3、 permitted without license from IHS-,-,-MSFC Technical Standard EM20 Title: Threaded Fasteners, Titanium Alloys, Usage Criteria for Launch Vehicles and Spacecraft Applications Document No.: MSFC-STD-557 Revision: B Effective Date: February 15, 2012 Page 2 of 9 CHECK THE MASTER LIST VERIFY THAT THIS
4、IS THE CORRECT VERSION BEFORE USE at https:/repository.msfc.nasa.gov/docs/multiprogram/MSFC-STD-557.pdf DOCUMENT HISTORY LOG Status (Baseline/ Revision/ Canceled) Document Revision Effective Date Description Baseline Baseline Release Revision A February 1, 2005 Update doc. Per MSFC rules review. Upd
5、ate applicable documents section. Change paragraph 4.9.1.2.2 to reflect new thread inspection documents. Revision B February 15, 2012 Revision B Release; document is authorized through MPDMS. Title: Changed to reflect intended usage in launch vehicles, delete specific chemical composition of titaniu
6、m to include all titanium fasteners. Revision: Changed from A to B Effective date: Changed Responsible organization: Changed from EM30 to EM20 Forward: Changed to reflect new custodian and division. Launch vehicles added to reflect applicability Scope: Launch vehicles added to reflect applicability
7、Section 1: Delete specific chemical composition of titanium to include all titanium fasteners. This change is reflected in the entirety of the document. Section 2: Applicable specifications, standards, and publications updated. Section 2.2: Replace ASTM E595.07 with NASA-STD-6016. Section 2.2: Added
8、 the address for ASME Section 3: Definition of “reuse” added Section 4.1-Delete specific chemical composition of titanium to include all titanium fasteners. Requirements documents update. Applicable sizes of fasteners redefined. Section 4.2-Helical coils and inserts added versus addressing only nuts
9、. Section 4.3-Previous 4.3 bullets deleted, causing all subsequent bullets to be revised. Governing controlling document for corrosion control changed. Previous statement regarding washers deleted. Changed the text in parentheses to: “bolt, washer, helical coils, insert, nut, and coatings” Section 4
10、.4 -Governing requirement for lubricants changed Section 4.5-Governing requirement for fluid compatibility changed. Previous wording of 4.5 deleted. Section 4.6- Requirement revised for clarity Section 4.7.1-Paragraph reworded for clarity. Section 4.8- Delete specific chemical composition of titaniu
11、m to include all titanium fasteners Section 4.8.1-Delete specific chemical composition of titanium to include all titanium fasteners Section 4.8.1.1-Replace illumination level with magnification level. Bulleted list substituted over previous document hierarchy. . Section 4.8.1.2-Paragraph revised fo
12、r clarity. Added System 21 and 22. Section 4.9.1.2.2-deleted Section 4.9.1.2.3-deleted Section 4.9-Inserts and helical coils added. Delete specific chemical composition of titanium to include all titanium fasteners Section 4.10-deleted Section 5.2- Add note to clarify use of NAS621 and NAS4004 with
13、titanium alloys other than Ti-6Al-4V. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MSFC Technical Standard EM20 Title: Threaded Fasteners, Titanium Alloys, Usage Criteria for Launch Vehicles and Spacecraft Applications Document No.: MSFC-STD-557 R
14、evision: B Effective Date: February 15, 2012 Page 3 of 9 CHECK THE MASTER LIST VERIFY THAT THIS IS THE CORRECT VERSION BEFORE USE at https:/repository.msfc.nasa.gov/docs/multiprogram/MSFC-STD-557.pdf FOREWORD 1. This standard specifies criteria for use of titanium alloy fastener systems for launch v
15、ehicles, spacecraft, and associated equipment. 2. Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to the custodian: Zachary H. Taylor/EM20, Materials and Processes Laboratory, NASA/George C. Marshal
16、l Space Flight Center, Huntsville, AL 35812. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MSFC Technical Standard EM20 Title: Threaded Fasteners, Titanium Alloys, Usage Criteria for Launch Vehicles and Spacecraft Applications Document No.: MSFC-ST
17、D-557 Revision: B Effective Date: February 15, 2012 Page 4 of 9 CHECK THE MASTER LIST VERIFY THAT THIS IS THE CORRECT VERSION BEFORE USE at https:/repository.msfc.nasa.gov/docs/multiprogram/MSFC-STD-557.pdf CONTENTS PARAGRAPH PAGE DOCUMENT HISTORY LOG . .2 FOREWORD .3 1. SCOPE . 5 2. APPLICABLE DOCU
18、MENTS 5 3. DEFINITION .7 4. GENERAL REQUIREMENTS . 7 5. NOTES . 8 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MSFC Technical Standard EM20 Title: Threaded Fasteners, Titanium Alloys, Usage Criteria for Launch Vehicles and Spacecraft Applications
19、Document No.: MSFC-STD-557 Revision: B Effective Date: February 15, 2012 Page 5 of 9 CHECK THE MASTER LIST VERIFY THAT THIS IS THE CORRECT VERSION BEFORE USE at https:/repository.msfc.nasa.gov/docs/multiprogram/MSFC-STD-557.pdf 1. SCOPE This standard establishes criteria for use of titanium alloy th
20、readed fastener systems for launch vehicles, spacecraft, and associated equipment. These criteria are applicable to items designed and fabricated by MSFC and its prime contractors for use on MFSC programs. 2. APPLICABLE DOCUMENTS 2.1 Government publications. The following documents form a part of th
21、is standard to the extent specified herein. Unless otherwise indicated, the issue in effect on date of invitation for bids or request for proposal shall apply. MIL-PRF-46010 Performance Specification, Lubricant, Solid Film, Heat Cured, Corrosion Inhibiting MIL-I-45914 Military Specification, Insert,
22、 Screw Thread - Locked In, Key Locked , General Specification For MIL-I-45931 Military specification: Insert, Screw Thread, Thin Wall, Locked In MIL-I-45932 Military Specification, Insert, Screw Thread, Thin Wall, Locked In, General Specification For NASA-STD-6016 Standard Materials and Processes Re
23、quirements for Space Craft (Copies of Specifications and Standards required by contractors in connection with specified procurement functions should be obtained from the procuring activity or as directed by the contracting officer.) 2.2 Other publications. The following documents form a part of this
24、 standard to the extent specificed herein. Unless otherwise indicated, the issue in effect on date of invitation for bids or request for proposal, shall apply. ANSI/ASME-B1.2 Gages and Gaging for Unified Inch Screw Threads Provided by IHSNot for ResaleNo reproduction or networking permitted without
25、license from IHS-,-,-MSFC Technical Standard EM20 Title: Threaded Fasteners, Titanium Alloys, Usage Criteria for Launch Vehicles and Spacecraft Applications Document No.: MSFC-STD-557 Revision: B Effective Date: February 15, 2012 Page 6 of 9 CHECK THE MASTER LIST VERIFY THAT THIS IS THE CORRECT VERS
26、ION BEFORE USE at https:/repository.msfc.nasa.gov/docs/multiprogram/MSFC-STD-557.pdf ANSI/ASME-B1.3M Screw Thread Gaging System for Acceptability -Inch and Metric Screw Threads (UN, UNR, UNJ, M, and MJ) (Applications for copies should be addressed to ASME International, Three Park Avenue, New York,
27、N.Y. 10016-5990) 2.2.1 NATIONAL AEROSPACE STANDARDS NAS621 Fasteners, Titanium Alloy, Procurement Specification NAS4004 Fasteners, 6A1-4V Titanium Alloy, Externally Threaded NASM8846 Inserts, Screw-Thread, Helical Coil NASM25027 Nut, Self-Locking , 250 F, 450 F, and 800 F (Applications for copies sh
28、ould be addressed to the Aerospace Industries Association of America, Inc., 1000 Wilson Blvd., Suite 1700, Arlington, VA 22209-3901) 2.2.2 SOCIETY OF AUTOMOTIVE ENGINEERING SAE-AS8879 Screw Threads -UNJ Profile, Inch Controlled Radius Root with Increased Minor Diameter 2.2.3 SAE AEROSPACE MATERIAL S
29、PECIFICATION SAE-AMS5525 Steel, Corrosion and Heat Resistant, Sheet, Strip, and Plate 15Cr-25.5Ni- 1.2Mo-2.1Ti-0.006B-0.30V, 1800 Degrees F (982 Degrees C) Solution Heat Treated SAE-AMS5732 Steel, Corrosion and Heat Resistant, Bars, Wire, Forgings, Tubing and Rings 15Cr-25.5Ni-1.2Mo-0.006B-0.30V Con
30、sumable Electrode Remelted 1800 Degrees F (982 Degrees C) Solution and Precipitation Heat Treated SAE-AMS5737 Steel, Corrosion and Heat Resistant Bars, Wire, Forgings, and Tubing 15Cr- 25.5Ni-1.2Mo-2.1Ti-0.006B-0.30V Consumable Electrode Melted 1650 Degrees F(899 Degrees C) Solution and Precipitatio
31、n Heat Treated SAE-AMS5758 Alloy Bars, Corrosion Resistant, 20Cr-35Ni-35Co-10Mo, Vacuum Induction Plus consumable Electrode Vacuum Melted, Solution Heat Treated For Work Strengthening Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MSFC Technical Sta
32、ndard EM20 Title: Threaded Fasteners, Titanium Alloys, Usage Criteria for Launch Vehicles and Spacecraft Applications Document No.: MSFC-STD-557 Revision: B Effective Date: February 15, 2012 Page 7 of 9 CHECK THE MASTER LIST VERIFY THAT THIS IS THE CORRECT VERSION BEFORE USE at https:/repository.msf
33、c.nasa.gov/docs/multiprogram/MSFC-STD-557.pdf (Applications for copies should be addressed to the SAE World Headquarters, 400 Commonwealth Drive, Warrendale, PA 15096-0001) 3. DEFINITION Reuse. When pertaining to fastening system elements, fasteners and helical coils, inserts, or nuts that are reins
34、talled with any amount of preload applied. 4. GENERAL REQUIREMENTS 4.1 Titanium alloy bolts shall comply with the requirements of the applicable sections of either NAS621 or NAS4004. Tailoring or exceptions (e.g, alloy, material strength, etc) shall be noted on the bolt standard part drawing. Titani
35、um bolt size shall be limited to less than 0.750 inch diameter. Any bolt size greater than 0.750 inch diameter shall be submitted to MSFC for review. 4.2 All nuts, helical coils, and inserts shall be self-locking, lubricated, and shall be made from material conforming to SAE-AMS5525, SAE-AMS5732, SA
36、E-AMS5737, SAE-AMS5758, or a MSFC approved corrosion resistant alloy and shall comply with the applicable sections of NASM25027, MIL-I-45914, MIL-I-45931, MIL-I-45932, or NASM8846. Tailoring or exceptions (e.g, alloy, material strength, etc) shall be noted on the bolt standard part drawing. 4.3 The
37、fastener system (bolt, washer, helical coil, inserts, nut and coating) shall be designed to prevent corrosion in accordance with the guidelines given in NASA-STD-6016. The use of cadmium or silver on any fastener system component is specifically prohibited. 4.4 Lubricants for nuts, helical coils and
38、 inserts shall be selected in accordance with the requirements of MIL-PRF-46010, NASM25027, MIL-I-49514, MIL-I-45931, MIL-I-49532, or NAS8846 and shall pass the requirements of NASA-STD-6016 for use in launch vehicles and space craft applications. Lubricants not meeting the requirements contained in
39、 these documents shall be submitted to MSFC for review. 4.5 All titanium alloy fasteners shall meet the requirements for fluid compatibility and for titanium in NASA-STD-6016. 4.6 Titanium alloy fasteners shall be prohibited from use in any application or design where failure of a single bolt or nut
40、 will cause the structure to become unstable and unable to carry design loads or will result in the design no longer meeting its intended function (i.e., a single point failure). 4.7 Allowable Bolt Loads. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,
41、-,-MSFC Technical Standard EM20 Title: Threaded Fasteners, Titanium Alloys, Usage Criteria for Launch Vehicles and Spacecraft Applications Document No.: MSFC-STD-557 Revision: B Effective Date: February 15, 2012 Page 8 of 9 CHECK THE MASTER LIST VERIFY THAT THIS IS THE CORRECT VERSION BEFORE USE at
42、https:/repository.msfc.nasa.gov/docs/multiprogram/MSFC-STD-557.pdf 4.7.1 The maximum ultimate tensile load for titanium bolts shall be no greater than sixty percent (60%) of the allowable ultimate tensile strength for the bolt material as published in the fastener design specification or procurement
43、 specification. The ultimate shear load may be up to 100% of the allowable shear strength values as published in the fastener design specification or procurement specification. 4.7.1.1 The total applied tensile load shall include the additive influences of installation preloading and service loading
44、. 4.8 Reuse of Titanium Alloy Threaded Fastener Systems. 4.8.1 Reuse of titanium alloy bolts shall be limited to fifteen (15) cycles, subject to the following requirements for inspection. 4.8.1.1 After removal of the components from the structure, the fastener components shall be visually inspected
45、under a magnification level of at least 5X for damage at the fastener surface. The following conditions shall be cause for rejection: a. Visible corrosion or corrosion products. b. Galling, stripping, scoring or scratching of threads or plating. c. Deformation of any part of the bolt. d. Foreign mat
46、erial in threads (not easily removed with a nonmetallic bristle brush and using an approved solvent). e. Cracks and discontinuities 4.8.1.2 After visual inspection, the fastener system components shall be inspected in accordance with the methods of measuring the characteristics of thread forms prese
47、nted in ANSI/ASME B1.3M. At a minimum, System 22 shall be used to inspect external thread characteristics and System 21 shall be used to inspect internal thread characteristics. Gages shall meet the requirements of ANSI/ASME B1.2. 4.8.2 Bolt threads shall be protected from damage during any handling
48、 operation. 4.9 Reuse of Nuts, Inserts, and Helical Coils Installed with Titanium Alloy Bolts. 4.9.1 Nuts, helical coils and inserts can be reused up to five (5) cycles, provided that the hardware pass the corrosion, galling, stripping, scoring, scratching, and foreign material in threads inspection requirements of 4.8.1.1, 4.8.1.2, and the prevailing and breakaway torque limits of NASM25027, MIL-I-45931, MIL-I-45931, MIL-I-45932, or NAS8
