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 there
2、from, 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 2011 SAE International All rights reserved. No part of this publication m
3、ay 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: 724-776-4970 (outside USA)
4、 Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AS28431A AEROSPACE STANDARD AS28431A Issued 2003-09 Reaffirmed 2008-07 Revised 2011-02 Supersedi
5、ng AS28431 Aerospace Hand Torque Wrenches (Mechanical, Impulse) RATIONALE Conversion of Federal Specification GGG-W-2843 dated May 7, 1993. 1. SCOPE AND CLASSIFICATION 1.1 Scope This SAE International Aerospace Standard covers requirements for micrometer adjustable, feel impulse, torque wrenches. Th
6、e torque wrench is used to apply a pre-set torque to threaded fasteners and other torque requirements. 1.2 Classification Torque wrenches covered by this specification shall be one of the following types and classifications, as specified. Type I Bi-directional torque wrench Class 1 Non-ratchet head
7、(precise clockwise torque) Class 2 Ratchet head (precise clockwise torque) Class 3 Non-ratchet head (precise counter-clockwise torque) Class 4 Ratchet head (precise counter-clockwise torque) Class 5 Interchangeable head (precise clockwise torque) Class 6 Interchangeable head (precise counter-clockwi
8、se torque) Type II Uni-directional torque wrench Class 1 Non-ratchet head (precise clockwise torque) Class 2 Ratchet head (precise clockwise torque) Class 3 Non-ratchet head (precise counter-clockwise torque) Class 4 Ratchet head (precise counter-clockwise torque) Class 5 Interchangeable head (preci
9、se clockwise torque) Class 6 Interchangeable head (precise counter-clockwise torque) 1.2.1 Class Accuracy Type I bi-directional torque wrenches shall have an accuracy of 4% in the precise torque direction, and 6% in the opposite direction, and shall signal in both directions. Type II uni-directional
10、 torque wrenches shall have an accuracy of 4% in the precise torque direction, and shall signal in the precise torque direction. SAE AS28431A Page 2 of 121.2.2 Accuracy Torque accuracy is defined as the difference between the applied torque and the pre-set torque divided by the pre-set torque expres
11、sed as a percentage. 2. APPLICABLE DOCUMENTS The following 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
12、 event of conflict between the text of this document 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. 2.1.1 SAE Publications Available from SAE Interna
13、tional, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org.AS4984 Coating Requirements for Aerospace Hand Tools 2.1.2 ASTM Publications Available from ASTM international, 100 Barr Harbor Drive, P.O. Box C700, West C
14、onshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org.ASTM E18 Rockwell Hardness and Rockwell Superficial Hardness of Metallic Materials, Standards Methods of Test for 2.1.3 ASME Publications Available from American Society of Mechanical Engineers, 22 Law Drive, P.O. Box 2900, Fairfield, NJ 07
15、007-2900, Tel: 973-882-1170, www.asme.org.ASME B107.4 Driving and Spindle Ends for Portable Hand, Air, and Electric Tools ASME B107.10 Handles and Attachments for Hand Socket Wrenches - Inch and Metric Series ASME B107.17 Gages and Mandrels for Wrench Openings 3. REQUIREMENTS 3.1 Torque Wrench The t
16、orque wrench shall have an accurate micrometer-type, pre-setting mechanism upon which the required torque can be hand set by adjusting the mechanism. The torque wrench shall have a locking mechanism which holds the pre-set torque securely during use of the torque wrench. Operation of the pre-setting
17、 mechanism and locking mechanism shall not require the use of tools or equipment. The torque wrench shall have a torque signaling device that meets the requirements of 3.3.6. 3.2 Illustrations The illustrations herein are descriptive and are not intended to preclude the purchase of torque wrenches o
18、therwise conforming to this specification. 3.2.1 Torque Wrench Type I and Type II, Class 1 and Class 3 Class 1 and Class 3 torque wrenches shall be similar to Figure 1; except 500 to 2000 ft-lb capacity torque wrenches similar to Figure 2. SAE AS28431A Page 3 of 123.2.2 Torque Wrench Type I and Type
19、 II, Class 2 and Class 4 Class 2 and Class 4 torque wrenches shall be similar to Figure 3. 3.2.3 Torque Wrench Type I and Type II, Class 5 and Class 6 Class 5 and Class 6 torque wrenches shall be similar to Figure 4. Interchangeable heads shall be similar to Figure 5, however, connection configurati
20、ons can be different than illustrated. 3.3 Design, Materials and Construction The torque wrench design, materials and construction shall be of uniform high quality adequate to meet the requirements of this specification and capable of providing repeated accuracy over an expected service period. 3.3.
21、1 HandleThe torque wrench shall have a metal handle of one-piece or multi-piece design using a threaded or other mechanically fitted joint. A suitable portion of the handle shall be knurled, grooved, ribbed or provided with a non-toxic rubber cover that facilitates turning of the adjustable portion
22、of the handle. 3.3.2 Drive Requirements Type I and Type II, Classes 1, 2, 3, 4 Torque wrenches of classes 1 through 4 shall have a male square drive with a spring-loaded steel ball or similar retaining mechanism which conforms to the requirements of ASME B107.4, and shall be tested in accordance wit
23、h 4.10. The spring-loaded steel ball or similar retaining mechanism shall be located as shown in Figure 1. The male square drive hardness shall be Rockwell C 40 to 60, and shall be tested in accordance with 4.10.1. On non-ratcheting torque wrenches, two opposite flats of the male square drive shall
24、be parallel within 5 degrees of the longitudinal axis of the torque wrench. 3.3.3 Drive Requirements - Classes 5 and 6 Interchangeable head class 5 and 6 torque wrenches shall have interchangeable connection on the end of the drive tang, which allows attachment of mating drive heads. The interchange
25、able connection shall have an enclosed retaining system to prevent accidental disengagement of the interchangeable head during normal use. The drive tang hardness shall be Rockwell C 40 to 60 and shall be tested in accordance with 4.10.1. 3.3.4 Interchangeable Head Requirements Type I and Type II, C
26、lass 5 and Class 6 Fixed square drive interchangeable heads shall conform to the requirements of ASME B107.4 and shall be tested in accordance with 4.10. Ratcheting interchangeable heads shall meet the requirements of 3.3.5. Open end, flare nut, and box interchangeable heads shall meet the dimension
27、al requirements of ASME B107.17M. The interchangeable head shall be designed so that interchanging one head for a different head shall not require the torque wrench to be recalibrated. The interchangeable head hardness shall be Rockwell C 40 to 60 and shall be tested in accordance with ASTM E18. The
28、 torque wrench and interchangeable heads shall be supplied by the same manufacturer. Markings shall meet the marking requirements in 3.10. FIGURE 1 TYPE I AND TYPE II, CLASSES 1 AND 3 TORQUE WRENCH, MICROMETER ADJUSTABLE, TORQUE PRE-SETTING, FEEL IMPULSE, NON-RATCHETING SAE AS28431A Page 4 of 12FIGU
29、RE 2 TYPE I AND TYPE II, CLASSES 1 AND 3 TORQUE WRENCH (500 TO 2 000 FT-LB CAPACITY), MICROMETER ADJUSTABLE TORQUE WRENCH, FEEL IMPULSE, NON-RATCHETING HEAD FIGURE 3 TYPE I AND TYPE II, CLASSES 2 AND 4 TORQUE WRENCH, MICROMETER ADJUSTABLE TORQUE, FEEL IMPULSE, RATCHETING HEAD FIGURE 4 TYPE I AND TYP
30、E II, CLASSES 5 AND 6 TORQUE WRENCH, MICROMETER ADJUSTABLE TORQUE, FEEL IMPULSE, INTERCHANGEABLE HEAD FIGURE 5 - INTERCHANGEABLE HEADS, FOR CLASSES 5 AND 6 TORQUE WRENCH SAE AS28431A Page 5 of 123.3.5 Ratchet Head Requirements Torque wrenches containing a ratchet head shall be designed in accordance
31、 with the applicable requirements of ASME B107.10 and shall be tested in accordance with ASME B107.10. 3.3.6 Signal and Release Mechanism The torque wrench shall incorporate a torque indicating device which signals by a physical impulse, with or without audible signal, and causes a temporary reducti
32、on in load when the pre-set torque has been reached. 3.4 Torque Scale The torque wrench shall have a graduated torque scale in the applicable units of torque measurement from the minimum to the maximum rated torque capacity. The torque scale shall be divided into equal graduation increments with the
33、 size of each increment equal to or less than that specified in Table 1. The graduation lines and numbers shall be cut, etched or stamped in a manner without damage to the finish or coatings. The torque wrench shall be permanently marked on the top of the torque wrench, or on the hand grip, with the
34、 units of torque measurement (e.g., ft-lb, in-lb). 3.4.1 Extended Torque Scale Markings If the torque scale extends below the minimum or above the maximum rated torque capacity specified in Table 1, the extended scale markings shall be consistent with the scale markings throughout the rated torque c
35、apacity and in conformance with the requirements of 3.4. Extended scale markings shall only exist throughout an extended torque capacity (see 3.5.1). 3.5 Torque Capacity Unless otherwise specified, the torque wrench shall have, as a minimum, the applicable torque rated capacity specified in Table 1.
36、 Unless otherwise specified, the torque wrench may have an extended torque capacity (see 3.5.1).3.5.1 Extended Torque Capacity If the torque wrench has an extended torque capacity with applicable torque scale markings below the minimum or above the maximum rated torque capacity specified in Table 1,
37、 the torque wrench shall meet all requirements of this specification, as modified (see 3.5.2), over the extended torque capacity. 3.5.2 Extended Torque Capacity Specifications If the torque wrench has an extended torque capacity (see 3.5.1), the requirements in this specification shall be modified a
38、s follows: Substitute the lowest torque value marked on the torque wrench in lieu of the “minimum rated torque capacity“, substitute the highest torque value marked on the torque wrench in lieu of the “maximum rated torque capacity“, and substitute the extended torque capacity in lieu of the “rated
39、torque capacity“. 3.6 Operating Load/Force: Torque wrench shall have a sufficient length to limit the maximum applied force at the center of the handgrip. Loads applied at the center of the hand grip shall not exceed the maximum forces shown in Table 2 when a rated torque wrench capacity is reached.
40、3.7 Torque Overload The torque wrench shall be capable of an overload of 125% of the maximum rated torque in both directions without damage, deformation, or loss of accuracy over the rated torque capacity. Subsequent to overload, the torque wrench shall, without repair or recalibration, be capable o
41、f meeting the requirements of this specification. The torque wrench overload test shall be tested in accordance with 4.7. SAE AS28431A Page 6 of 12TABLE 1 - SIGNALING TORQUE WRENCH CAPACITIES RatedTorqueCapacity(Minimum-Maximum)in-lbRatedTorqueCapacity(Minimum-Maximum)ft-lbDriveSizeinIncrementGradua
42、tions(Maximum)Class1Class2Class3Class4Class5Class610-50 - 1/4 1 in-lb x x x x x x 30-150 - 1/4 2 in-lb x x x x x x 30-150 - 3/8 1 in-lb x x x x x x 40-200 - 1/4 1 in-lb x x x x x x 40-200 - 1/4 2 in-lb x x x x x x 40-200 - 3/8 1 in-lb x x x x x x 150-750 - 3/8 5 in-lb x x x x x x 200-1000 - 3/8 5 in
43、-lb x x x x x x 360-1800 - 1/2 10 in-lb x x x x x x 250-2500 - 1/2 10 in-lb x x x x x x 600-3000 - 1/2 10 in-lb x x x x x x 700-1600 - 1/2 10 in-lb x x x x x x 1200-4800 - 3/4 40 in-lb x x x x - 15-75 3/8 1/2 ft-lb x x x x x x - 16-80 3/8 1/2 ft-lb x x x x x x - 16-80 1/2 1/2 ft-lb x x x x x x - 20-
44、100 3/8 1/2 ft-lb x x x x x x - 30-150 1/2 1 ft-lb x x x x x x - 40-200 1/2 1 ft-lb x x x x x x - 50-250 1/2 1 ft-lb x x x x x x - 60-300 3/4 5 ft-lb x x x x x x - 100-500 3/4 5 ft-lb x x x x - 120-600 3/4 5 ft-lb x x x x - 140-700 1 2 ft-lb x x x x - 500-2000 1 10 ft-lb x x x x TABLE 2 - OPERATING
45、LOAD (FORCE APPLIED AT CENTER OF HANDGRIP) Drive Size inDrive Size mmMaximum Load lbMaximum Load N1/4 6.3 50 220 3/8 10 125 555 1/2 12.5 175 780 3/4 20 250 1110 1 contractors assigned unique serial number, rated torque capacity, specified accuracy; date of calibration; and the actual calibration rea
46、dings applicable to the torque wrench. 3.14 Workmanship Workmanship shall be of the highest grade throughout and equal in every respect to the best commercial practices. The torque wrench shall be free of all defects that would impair serviceability, durability, safety or appearance. 4. TEST PROCEDU
47、RES 4.1 Responsibility for Inspection and Testing Unless otherwise specified, the supplier is responsible for all inspection requirements as specified herein. The supplier is also responsible for insuring that materials and components used were manufactured, tested and inspected in accordance with t
48、he requirements of referenced subsidiary specifications and standards to the extent specified herein. 4.2 Test Samples All classes shall have two test samples for each rated torque capacity, drive size and graduation increments examined and tested in accordance with 4.3. The interchangeable head for
49、 class 5 and 6 torque wrench testing shall be square drive or ratchet of sufficient torque capacity to withstand the full scale torque of the wrench. Failure of any examination ortest shall be cause for rejection. SAE AS28431A Page 10 of 124.3 Type of Testing The torque wrench shall be tested in accordance with 4.3.1 and 4.3.2. 4.3.1 Product design qualification t
