1、_SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising theref
2、rom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2010 SAE International All rights reserved. No part of this publication ma
3、y be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970 (outside US
4、A) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AS7456BAEROSPACESTANDARDAS7456 REV. B Issued 1991-02 Reaffirmed 2006-05 Revised 2010-06 Superse
5、ding AS7456A Studs, Steel, Low Alloy Heat Treated, Roll Threaded RATIONALECorrect paragraph numbering starting at 3.3 Fabrication thru 3.7.3.3.2 to align with other paragraphs contents, Tables and Figures and editorial comments 1. SCOPE 1.1 Type This procurement specification covers aircraft quality
6、 studs made from a low alloy steel of the type identified under the Unified Numbering System as UNS G87400, and of a series of room temperature tensile strengths ranging from 125 000 psi to 185 000 psi. 1.2 Application Primarily for aerospace propulsion system applications in light alloys where good
7、 strength is required and the part is protected against corrosion. 1.3 Safety - Hazardous Materials While the materials, methods, applications, and processes described or referenced in this specification may involve the use of hazardous materials, this specification does not address the hazards whic
8、h may be involved in such use. It is the sole responsibility of the user to ensure familiarity with the safe and proper use of any hazardous materials and to take necessary precautionary measures to ensure the health and safety of all personnel involved. 2. REFERENCES 2.1 Applicable Documents The fo
9、llowing publications form a part of this document to the extent specified herein. The latest issue of SAE publications shall apply. The applicable issue of the other publications shall be the issue in effect on the date of the purchase order. In the event of conflict between the text of this documen
10、t and references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or n
11、etworking permitted without license from IHS-,-,-SAE AS7456B Page 2 of 182.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org.AMS2750 Pyrometry AMS6322 Steel Ba
12、rs, Forgings, and Rings 0.50Cr - 0.55Ni - 0.25Mo (0.38 - 0.43C) (SAE 8740) AMS6327 Steel Bars and Forgings, 0.50Cr - 0.55Ni - 0.25Mo (0.38 - 0.43C) (SAE 8740), Heat Treated, 125 ksi(862 MPa) Tensile Strength AS3062 Bolts, Screws, and Studs, Screw Thread Requirements AS3063 Bolts, Screws, and Studs,
13、Geometric Control Requirements 2.1.2 U.S. Government Publications Available from the Document Automation and Production Service (DAPS), Building 4/D, 700 Robbins Avenue, Philadelphia, PA 19111-5094, Tel: 215-697-6257, http:/assist.daps.dla.mil/quicksearch.MIL-STD-2073-1 Military Packaging, Standard
14、Practice for 2.1.3 ASTM Publications Available from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM E140 Standard Hardness Tables for Metals ASTM E1444 Magnetic Particle Examination ASTM E8 Tension Testing of Metallic
15、Materials 2.1.4 ASME Publications Available from American Society ofMechanical Engineers, 22 Law Drive, P.O. Box 2900, Fairfield, NJ 07007-2900, Tel: 973-882-1170, www.asme.org.ASME B46.1 Surface Texture (Surface Roughness, Waviness, and Lay) 2.1.5 AIA Publications Available from Aerospace Industrie
16、s Association, 1000 Wilson Boulevard, Suite 1700, Arlington, VA 22209-3928, Tel: 973-358-1000, www.aia-aerospace.org.NASM1312-6 Fastener Test Methods, Method 6, Hardness NASM1312-8 Fastener Test Methods, Method 8, Tensile Testing NASM1312-12 Fastener Test Methods, Method 12, Plating Thickness Copyri
17、ght SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AS7456B Page 3 of 182.2 Definitions BURR: A rough edge or ridge left on the metal due to cutting, grinding, piercing, or blanking operation. COLD ROLLING
18、: Forming material below the recrystallization temperature. CRACK: Rupture in the material which may extend in any direction and which may be intercrystalline or transcrystalline in character. DEFECT: Any nonconformance of the unit or the product with specified requirements. DEFECTIVE: A unit of the
19、 product which contains one or more defects. DISCONTINUITY: An interruption in the normal physical structure or configuration of a part; such as a lap, seam, inclusion, crack, machining tear, or stringer. HEAT PATTERN: A discernible difference in etched appearance between the head and the shank caus
20、ed by forming of the head. INCLUSION: Nonmetallic particles originating from the material making process. They may exist as discrete particles or strings of particles extending longitudinally. LAP: Surface imperfection caused by folding over metal fins or sharp corners and then rolling or forging th
21、em into the surface. The allowable lap depth shall not exceed the limit specified herein. The minimum condition that shall be rated as a lap is a fold having its length equal to or greater than three times its width with a depth of 0.0005 in when viewed at 200X magnification. MACHINING TEAR: A patte
22、rn of short jagged individual cracks, generally at right angles to the direction of machining, frequently the result of improperly set cutting tools, or dull cutting tools. PRODUCTION INSPECTION LOT: Shall be all finished parts of the same part number, made from a single heat of alloy, heat treated
23、at the same time to the same specified condition, produced as one continuous run, and submitted for manufacturers inspection at the same time. SEAM: Longitudinal surface imperfection in the form of an unwelded, open fold in the material. STRINGER: A solid nonmetallic impurity in the metal bar, often
24、 the result of an inclusion that has been extended during the rolling process. TIGHT BURR: A burr closely compacted and binding in the periphery of a part without loose ends and is within the dimensional limits of the part. 2.3 Unit Symbols A - ampere F - degree Fahrenheit h - hour in - inch in2- sq
25、uare inch min - minute of time % - percent (1% = 1/100) lbf - pounds force psi - pounds force per square inch sp gr - specific gravity Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AS7456B Page
26、 4 of 183. TECHNICAL REQUIREMENTS 3.1 Material Shall be AMS6322 or AMS6327 steel, unless otherwise specified on the part drawing. 3.2 Design Finished (completely manufactured) parts shall conform to the following requirements. 3.2.1 Dimensions The dimensions of finished parts, after all processing,
27、including plating, shall conform to the part drawing. Dimensions apply after plating but before coating with solid film lubricants. 3.2.2 Surface Texture Surface texture of finished parts, prior to plating or coating, shall conform to the requirements as specified on the part drawing, determined in
28、accordance with ASME B46.1. 3.2.3 Threads Screw thread UNJ profile and dimensions shall be in accordance with AS8879, unless otherwise specified on the part drawing. Tolerances for pitch diameter of stud end threads shall be as specified on the part drawing. The special stud end thread requirements
29、shall be in accordance with AS3062 for the following requirements: a. Lead and half-angle variations b. Taper c. Out-of-roundness d. Stud lead threads e. Stud thread runout 3.2.3.1 The requirements for thread crest variations, locking holes in the nut end thread, incomplete lead thread, and thread r
30、unout on nut end thread shall be as specified in AS3062. 3.2.3.2 Chamfer The entering end of the thread (both ends) shall be chamfered as specified on the part drawing. 3.2.4 Geometric Tolerances Part features shall be within the geometric tolerances specified on the part drawing and, where applicab
31、le, controlled in accordance with AS3063. 3.3 Fabrication 3.3.1 Blanks Shall be machined sufficiently to remove surface defects and decarburization except as noted in 3.7.2.3. Blanks may be produced by machining, upsetting, extruding, or by a combination of these methods. 3.3.1.1 When a shoulder or
32、shoulders are produced by upsetting, the metal removed from the bearing surface shall be as little as practicable to provide a clean, smooth surface. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-S
33、AE AS7456B Page 5 of 183.3.2 Heat Treatment Unless machined from heat treated stock, blanks shall, before finishing the shank and rolling the threads, be heat treated as follows 3.3.2.1 Heating Equipment Furnaces may be any type ensuring uniform temperature throughout the parts being heated and shal
34、l be equipped with, and operated by, automatic temperature controllers and data recorders conforming to AMS2750. The heating medium or atmosphere shall cause no surface hardening by carburizing or nitriding nor decarburization other than that permitted by 3.7.2.2 and 3.7.2.3. 3.3.2.2 Hardening Blank
35、s of AMS6322 shall be uniformly heated to 1550 F, held at heat for not less than 15 min, and quenched in oil. For other steels, when specified, the temperature shall be as agreed upon by purchaser and vendor. 3.3.2.3 Tempering Hardened blanks shall be tempered by heating uniformly to the temperature
36、 necessary to produce the specified hardness and microstructure, holding at heat for not less than 1 h, and cooling. 3.3.3 Oxide and Decarburization Removal Surface oxide, oxide penetration, and decarburization except as permitted in 3.7.2.3, resulting from prior heat treatment, shall be removed fro
37、m the full body diameter and the bearing surfaces, as applicable, of the heat treated blanks prior to rolling the threads. The removal process shall produce no intergranular attack or corrosion of the blanks. 3.3.4 Thread Rolling Threads shall be formed on the heat treated and finished blanks by a s
38、ingle rolling process for each end after removal of oxide and decarburization as in 3.3.3. 3.4 Product Marking Each part shall be marked for oversize on stud end thread and for material code on the nut end as specified on the part drawing. The markings may be formed by stamping, depressed 0.010 in m
39、aximum, with rounded root form on depressed characters.3.5 Plating When required, any protective treatment shall be as specified on the part drawing. 3.6 Mechanical Properties Parts shall conform to the requirements of 3.6.1 and 3.6.2. Threaded members of gripping fixtures for tensile test shall be
40、of sufficient size and strength to develop the full strength of the part without stripping the thread. The loaded portion of theshank shall have two to three full thread turns from the thread runout exposed between the loading fixtures during tensile test. Finished parts shall be tested in accordanc
41、e with the following applicable test methods a. Hardness: MIL-STD-1312-6 in accordance with NASM1312-6. b. Room Temperature Ultimate Tensile Strength: MIL-STD-1312-8 in accordance with NASM1312-8. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or netw
42、orking permitted without license from IHS-,-,-SAE AS7456B Page 6 of 183.6.1 Ultimate Tensile Strength at Room Temperature 3.6.1.1 Finished Parts Parts having hardness not lower than 26 HRC shall have an ultimate tensile load not lower than that specified in Table 3 and shall be tested to failure, fi
43、rst measuring and recording the maximum tensile load achieved. If the size or shape of the part is such that failure would occur outside the threaded section but the part can be tested satisfactorily, such as parts having a shank diameter equal to or less than the thread root diameter or having an u
44、ndercut, parts shall conform to only the ultimate tensile requirements of 3.6.1.2; for such parts, the diameter of the area on which stress is based shall be the actual measured minimum diameter of the part. 3.6.1.2 Machined Test Specimens If the size or shape of the part is such that a tensile test
45、 cannot be made on the part, tensile tests shall be conducted in accordance with ASTM E 8 on specimens prepared as in 4.5. Such specimens shall meet the following requirements in Table 1 for the applicable hardness: TABLE 1 - TENSILE PROPERTIES OF SPECIMENS MINIMUM HARDNESS OF SPECIFIC RANGE HRCULTI
46、MATE TENSILE STRENGTH PSI, MINIMUMELONGATIONIN 2 IN OR 4D %, MINIMUM REDUCTIONOF AREA %, MINIMUM26 125 000 15 52 32 145 000 13 50 36 165 000 12 47 40 185 000 10 43 3.6.1.2.1 When permitted by purchaser, hardness tests on the end of parts may be substituted for tensile tests of machined specimens. 3.
47、6.2 Hardness Shall be uniform within the range 26 to 32 HRC, unless otherwise specified on the part drawing, but hardness of the threaded sections may be higher as a result of the cold working operations. 3.7 QualityParts shall be uniform in quality and condition, clean, sound, smooth, and free from
48、 burrs and foreign materials, and from imperfections detrimental to their performance. 3.7.1 Macroscopic Examination Parts or sections of parts, as applicable, shall be etched in a solution consisting of approximately 50% hydrochloric acid (sp gr 1.19), and 50% water for sufficient time to reveal flow lines but not longer than 15 min, and then be examined at a magnification of approximately 20X to determine conformance to the requirements of 3.7.1.1, 3.7.1.2, and 3.7.1.3, except that examination for thread imperfections as specified in 3.7.1.3 should be made by microscopic examination of
