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 revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2013 SAE International All rights reserved. No part of this p
3、ublication may 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: +1 724-776-497
4、0 (outside USA) 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/AMS2251H AEROSPACE MATERIAL SPECIFICATION AMS2251 REV. H Issued 1945-05 Revised 2
5、006-09 Reaffirmed 2013-11 Superseding AMS2251G Tolerances Low-Alloy Steel Bars RATIONALE AMS2251H has been reaffirmed to comply with the SAE five-year review policy. 1. SCOPE This specification covers established inch/pound manufacturing tolerances applicable to low-alloy steel bars ordered to inch/
6、pound dimensions. These tolerances apply to all conditions, unless otherwise noted. The term “exclusive” is used to apply only to the higher figure of the specified range. 1.1 No clear cut demarcation is available to differentiate between bar and wire products, so no definitions of these products ar
7、e included. 2. DIAMETER OR THICKNESS 2.1 Cold Finished 2.1.1 Cold Drawn Table 1 includes tolerances for bars that have been annealed, spheroidize annealed, normalized, normalized and tempered, or quenched and tempered before cold finishing. This table does not include tolerances for bars that are sp
8、heroidize annealed, normalized, normalized and tempered, or quenched and tempered after cold finishing. SAE INTERNATIONAL AMS2251H Page 2 of 7 2.1.1.1 Width governs the tolerances for both width and thickness of flats. For example, when the maximum of carbon range is up to 0.28, inclusive, for a fla
9、t 2.000 inches wide and 1.000 inch thick, the width tolerance is 0.006 inch and the thickness tolerance is the same, namely, 0.006 inch. TABLE 1 - TOLERANCES, INCH, MINUS ONLY; MAXIMUM OF CARBON RANGE, % Specified Diameter of Thickness Inches Up to 0.28 Carbon,incl Over 0.28 to 0.55 Carbon,incl Up t
10、o 0.55 Carbon,incl, Stress Relieved or Annealed After Cold Finishing Over 0.55, Carbon, With orWithout Stress Relieving or Annealing After Cold Finishing, and All CarbonsQuenched and Tempered or Normalized and Tempered Before Cold Finishing ROUNDS Up to 1.000, incl, in coils 0.002 0.003 0.004 0.005
11、Up to 1.500, incl 0.003 0.004 0.005 0.006 Over 1.500 to 2.500, incl 0.004 0.005 0.006 0.007 Over 2.500 to 4.000, incl 0.005 0.006 0.007 0.008 HEXAGONS Up to 0.750, incl 0.003 0.004 0.005 0.007 Over 0.750 to 1.500, incl 0.004 0.005 0.006 0.008 Over 1.500 to 2.500, incl 0.005 0.006 0.007 0.009 Over 2.
12、500 to 3.125, incl 0.006 0.007 0.008 0.010 Over 3.125 to 4.000, incl 0.006 - - - SQUARES Up to 0.750, incl 0.003 0.005 0.006 0.008 Over 0.750 to 1.500, incl 0.004 0.006 0.007 0.009 Over 1.500 to 2.500, incl 0.005 0.007 0.008 0.010 Over 2.500 to 4.000, incl 0.007 0.009 0.010 0.012 Over 4.000 to 5.000
13、, incl 0.011 - - - FLATS Specified Width, Inches Up to 0.750, incl 0.004 0.005 0.007 0.009 Over 0.750 to 1.500, incl 0.005 0.006 0.009 0.011 Over 1.500 to 3.000, incl 0.006 0.007 0.011 0.013 Over 3.000 to 4.000, incl 0.007 0.009 0.012 0.017 Over 4.000 to 6.000, incl 0.009 0.011 0.013 0.021 Over 6.00
14、0 0.014 - - - 2.1.1.2 When rough turned round bars are permitted, the tolerances in Table 1 shall be doubled. 2.1.1.3 The tolerances for flats apply to both width and thickness. 2.1.1.4 Tolerances in the column headed “Over 0.28 to 0.55 carbon, inclusive” also apply to all carbons up to 0.55 maximum
15、, annealed or normalized before cold finishing. SAE INTERNATIONAL AMS2251H Page 3 of 7 2.1.2 Machined Bars Tolerances for machined bars 0.375 inch and over in specified diameter or thickness are shown in Table 2. Bars up to 0.375 inch, exclusive, in specified diameter or thickness are supplied cente
16、rless ground. TABLE 2 - TOLERANCES, MACHINED BARS Specified Diameter or Thickness Inches Tolerance plus only Inch Out of Round Inch Over 0.375 to 2.000, incl 0.016 0.008 Over 2.000 to 4.000, incl 0.031 0.016 Over 4.000 0.031 0.016 2.1.3 Centerless Ground Bars Tolerances for centerless ground bars 0.
17、125 to 4.062 inches, inclusive, in specified diameter are shown in Table 3. Bars over 4.062 inches specified diameter are supplied machined. TABLE 3 - TOLERANCES, CENTERLESS-GROUND BARS Specified Diameter Inches Tolerance plus or minus Inch Out of Round Inch 0.125 to 0.3125, excl 0.001 0.001 0.3125
18、to 0.500, excl 0.0015 0.0015 0.500 to 1.000, excl 0.002 0.002 1.000 to 1.500, incl 0.0025 0.0025 Over 1.500 to 3.250, incl 0.003 0.003 Over 3.250 to 4.062 0.005 0.005 2.1.4 Ground and Polished Rounds See Table 4. TABLE 4 - TOLERANCES, GROUND AND POLISHED ROUNDS Specified Diameter Inches Tolerance In
19、ch Minus only Over Up to 1.500, incl 0.001 Over 1.500 to 2.500, excl 0.0015 Over 2.500 to 3.000, incl 0.002 Over 3.000 to 4.000, incl 0.003 SAE INTERNATIONAL AMS2251H Page 4 of 7 2.2 Hot Finished 2.2.1 Rounds and Squares See Table 5. 2.2.1.1 Out-of-round is the difference between the maximum and min
20、imum diameters of the bar, measured at the same cross-section. Out-of-square is the difference in the two dimensions at the same cross-section of a square bar between opposite faces. TABLE 5 - TOLERANCES, HOT FINISHED ROUNDS AND SQUARES Specified Diameter or Thickness Inches Tolerance Inch Plus Tole
21、rance Inch Minus Out-of-Round or Out-of-Square Inch Up to 0.3125, incl 0.005 0.005 0.008 Over 0.3125 to 0.4375, incl 0.006 0.006 0.009 Over 0.4375 to 0.625, incl 0.007 0.007 0.010 Over 0.625 to 0.875, incl 0.008 0.008 0.012 Over 0.875 to 1.000, incl 0.009 0.009 0.013 Over 1.000 to 1.125, incl 0.010
22、0.010 0.015 Over 1.125 to 1.250, incl 0.011 0.011 0.016 Over 1.250 to 1.375, incl 0.012 0.012 0.018 Over 1.375 to 1.500, incl 0.014 0.014 0.021 Over 1.500 to 2.000, incl 0.016 0.016 0.023 Over 2.000 to 2.500, incl 0.031 0 0.023 Over 2.500 to 3.500, incl 0.047 0 0.035 Over 3.500 to 4.500, incl 0.063
23、0 0.046 Over 4.500 to 5.500, incl 0.078 0 0.058 Over 5.500 to 6.500, incl 0.125 0 0.070 Over 6.500 to 8.250, incl 0.156 0 0.085 Over 8.250 to 9.500, incl 0.188 0 0.100 Over 9.500 to 10.000, incl 0.250 0 0.120 2.2.2 Hexagons and Octagons See Table 6. TABLE 6 - TOLERANCES, HOT FINISHED HEXAGONS AND OC
24、TAGONS Specified Distance Between Parallel Sides, Inches Tolerance Inch Plus Tolerance Inch Minus Maximum Difference, Inch, 3 Measurements, For Hexagons Only Up to 0.500, incl 0.007 0.007 0.011 Over 0.500 to 1.000, incl 0.010 0.010 0.015 Over 1.000 to 1.500, incl 0.021 0.013 0.025 Over 1.500 to 2.00
25、0, incl 0.031 0.016 0.031 Over 2.000 to 2.500, incl 0.047 0.016 0.047 Over 2.500 to 3.500, incl 0.063 0.016 0.063 SAE INTERNATIONAL AMS2251H Page 5 of 7 2.2.3 Square-Edged and Round-Edged Flats See Table 7. 2.2.3.1 Flats over 6.000 to 8.000 inches, inclusive, in specified width, are not available as
26、 hot rolled alloy steel bars in thicknesses under 0.230 inch. 2.2.3.2 Tolerances shall be negotiated for flats over 6.000 to 8.000 inches, inclusive, in specified width and over 3.000 inches in specified thickness. TABLE 7 - THICKNESS TOLERANCES, INCH, PLUS AND MINUS; THICKNESS RANGES, INCH Specifie
27、d Width Inches 0.203 to 0.230, excl 0.230 to 0.250,excl 0.250 to 0.500,incl Over 0.500 to 1.000,incl Over 1.000 to 2.000,incl Over 2.000 to 3.000,incl Over 3.00 Width ToleranceInch Plus Width ToleranceInch Minus Over Up to 1.000, incl 0.007 0.007 0.008 0.010 - - - 0.016 0.016 Over 1.000 to 2.000, in
28、cl 0.007 0.007 0.012 0.015 0.031 - - 0.031 0.031 Over 2.000 to 4.000, incl 0.008 0.008 0.015 0.020 0.031 0.047 0.047 0.063 0.031 Over 4.000 to 6.000, incl 0.009 0.009 0.015 0.020 0.031 0.047 0.047 0.094 0.063 Over 6.000 to 8.000, incl - 0.015 0.016 0.025 0.031 0.047 - 0.125 0.094 3. WIDTH Included i
29、n Section 2. 4. LENGTH 4.1 Cold Finished No requirements specified. 4.2 Hot Finished 4.2.1 Hot Sheared 4.2.1.1 Rounds, Squares, Hexagons, and Octagons See Table 8. TABLE 8 - TOLERANCES, INCHES, PLUS ONLY; LENGTH RANGES, FEET Specified Diameter or Distance Between Parallel Sides Inches 5 to 10, excl
30、10 to 20, excl 20 to 30, excl 30 to 40, excl 40 to 60, excl Over Up to 1.000, incl 0.500 0.750 1.250 1.750 2.250 Over 1.000 to 2.000, incl 0.625 1.000 1.500 2.000 2.500 Over 2.000 to 5.000, incl 1.000 1.500 1.750 2.250 2.750 Over 5.000 to 9.500, incl 2.000 2.500 2.750 3.000 3.250 SAE INTERNATIONAL A
31、MS2251H Page 6 of 7 4.2.1.2 Round-Edged and Square-Edged Flats See Table 9. TABLE 9 - TOLERANCES, INCHES, PLUS ONLY; LENGTH RANGES, FEET Specified Dimensions Inches Width Specified Dimensions Inches Thickness 5 to 10, excl 10 to 20, excl 20 to 30, excl 30 to 40, excl 40 to 60, excl Up to 3.000, incl
32、 Up to 1.000 incl Over 1.000 0.500 0.625 0.750 1.000 1.250 1.500 1.750 2.000 2.250 2.500 Over 3.000 to 6.000, incl Up to 1.000, incl Over 1.000 0.625 1.000 1.000 1.500 1.500 1.750 2.000 2.250 2.500 2.750 Over 6.000 to 8.000, incl Up to 1.000, incl Over 1.000 to 3.000, incl 0.750 1.250 1.250 1.750 1.
33、750 2.000 3.500 3.500 4.000 4.000 4.2.2 Hot Sawn 4.2.2.1 Rounds, Squares, Hexagons, and Octagons See Table 10. TABLE 10 - TOLERANCES, INCHES, PLUS ONLY; LENGTH RANGES, FEET Specified Diameter or Distance Between Parallel Sides Inches 10 to 20, excl 20 to 30, excl 30 to 40, excl 40 to 60, excl Over 2
34、.000 to 5.000, incl 1.500 1.750 2.250 2.750 Over 5.000 to 9.500, incl 2.250 2.750 3.000 3.250 4.2.2.2 Round-Edged and Square-Edged Flats See Table 11. TABLE 11 - TOLERANCES, INCHES, PLUS ONLY; LENGTH RANGES, FEET Specified Dimension Width Inches Specified Dimension Thickness Inches 10 to 20, excl 20
35、 to 30, excl 30 to 40, excl 40 to 60, excl 3.000 and over 1.000 and over 1.500 1.750 2.250 2.750 4.2.3 Special Straightened and Machine Cut on Both Ends See Table 12. TABLE 12 - TOLERANCES, INCH; LENGTH RANGES, FEET Specified Diameter of Rounds Thickness of Hexagons and Squares Width of Flats Inches
36、 Up to 12, incl Plus Up to 12, incl Minus Over 12 to 25, incl Plus Over 12 to 25, incl Minus Over Up to 3.000, incl 0.188 0.062 0.250 0.062 Over 3.000 to 6.000, incl 0.250 0.062 0.375 0.062 Over 6.000 to 8.000, incl 0.375 0.062 0.500 0.062 Over 8.000 to 9.500, incl 0.500 0.062 0.625 0.062 4.2.3.1 If
37、 bars are ordered with tolerances all plus or all minus, the unilateral tolerance shall be the arithmetic sum of the plus and minus tolerances of Table 12. SAE INTERNATIONAL AMS2251H Page 7 of 7 5. STRAIGHTNESS 5.1 Cold Finished No requirements specified. 5.2 Hot Finished Shall be of such straightne
38、ss that the maximum edgewise curvature (depth of arc) shall be not greater than 0.250 inch in any 5 feet of length or 0.050 inch x length in feet for shorter lengths. 5.2.1 When so ordered, bars shall be of such straightness that the maximum edgewise curvature (depth of arc) shall be not greater tha
39、n 0.125 inch in any 5 feet of length or 0.025 inch x length in feet for shorter lengths. 6. FLATNESS No requirements specified. 7. SPECIAL TOLERANCES 7.1 Cold Drawn, Rounds For maximum of carbon range over 0.28 and all carbons heat treated or stress relieved, the tolerances in Table 13 apply when sp
40、ecified on the purchase order. TABLE 13 - TOLERANCES Nominal Diameter Inches Tolerance Inch Minus Only Over Up to 1.500, incl 0.004 Over 1.500 to 2.000, incl 0.006 7.2 Across-Corners, Hexagons The requirements of Table 14 apply to cold finished hexagons when specified on the purchase order. TABLE 14
41、 - DISTANCE ACROSS CORNERS Specified Thickness Inches Distance Across Corners Inches, min Specified Thickness Inches Distance Across Corners Inches, min Specified Thickness Inches Distance Across Corners Inches, min 0.1875 0.210 0.500 0.564 0.750 0.848 0.2188 0.245 0.5625 0.635 0.8125 0.919 0.250 0.
42、280 0.5938 0.670 0.875 0.990 0.3125 0.351 0.625 0.706 0.9375 1.062 0.375 0.423 0.6875 0.775 1.000 1.133 0.4375 0.492 1.0625 1.203 8. NOTES 8.1 The change bar (|) located in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have bee
43、n made to the previous issue of this specification. An (R) symbol to the left of the document title indicates a complete revision of the specification, including technical revisions. Change bars and (R) are not used in original publications, nor in specifications that contain editorial changes only. 8.2 Terms used in AMS are clarified in ARP1917. PREPARED BY AMS COMMITTEE “E”
