1、This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2015 by Navistar, Inc. JUNE 2015 Page 1 of 6 NAVISTAR, INC. Material, Parts, and Process Specifications (
2、MPAPS) NUMBER: MPAPS S-EM-1.101-GS/PL Former Designation: ESP-EM-1.101-GS TITLE: Hex Nuts Metric Series (Noun Code 5780) CURRENT REV No.: 1506 DATE: June 2015 WRITTEN/EDITED BY: Materials Engineering APPROVED BY: Materials Engineering SUPERSEDES: ESP-EM-1.101-GS - August 2006 PRINTED COPIES OF THIS
3、DOCUMENT MUST BE VERIFIED FOR CURRENT REVISION This specification may involve hazardous materials, equipment, and procedures. This specification does not purport to address all of the safety issues associated with its use. The user is responsible to consult appropriate safety and health practices an
4、d to determine the applicability of regulatory limits prior to use. Change Notice: Changed to New MPAPS format; Combined GS, GI, PP, NPP. 1.0 GENERAL: Implementation of this standard must be in accordance with the policies and procedures outlined in MPAPS S-A-0.101. There may also be supplemental gr
5、oup instructions in regard to use of metric standards that should be taken into account. This standard may differ in some respects with certain segments of ISO and national standards. In recognition of these possible differences, the sizes and tolerance ranges used were established in an effort to e
6、nable the use of commercially available items, dimensionally interchangeable worldwide. This specification contains the essentials of the following standards: International Organization for Standardization: ISO 4032 American National Standards Institute: ANSI B18.2.4.1M German Institute of Standardi
7、zation: DIN 970 For M10, M12 and M14 sizes, across flats, across corners and height dimensions in the table on last page, reflect the latest ISO/TC2 decisions. Many nuts presently being manufactured and used, will be to the old ISO dimensions (1 mm larger across flats). It is recommended that locati
8、ons such as European operations sourcing to old ISO dimensions continue to do so until a complete and cost effective transition to the new dimensions is accomplished. Locations sourcing to the new ANSI/ISO dimensions (as stated in this standard) are urged to monitor stock and procurement practices t
9、o assure consistent production availability of the latest nuts. For M22 size, the dimensions across flats and corners are shown per latest ISO/TC2 decisions. The previous width across flats and corners, which are shaded in gray, will be deleted from the standard on its next issue. Inch series nuts m
10、ay be found in MPAPS S-E-1.101-GS/PL. NUMBER: MPAPS S-EM-1.101-GS/PL TITLE: Hex Nuts Metric Series REVISION: 1506 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent li
11、ability. 2015 by Navistar, Inc. JUNE 2015 Page 2 of 6 2.0 CONTENTS: 3.0 DESIGN CONSIDERATION: The use of thru hardened washers is recommended in high strength bolted connections and in Class 8.8 applications involving oversize or slotted holes. Coarse thread series only will be considered as part of
12、 this standard, because of the following advantages: Less tendency to cross thread. Resists nicking and has less stress concentration at the thread roots. Less likely to be seriously affected by decarburization and oversize minor diameter of internal threads. 4.0 METRIC-INCH RELATED SIZES: During th
13、e inch to metric design transition period, the following chart of related sizes can be used for reference. This information is not to be considered as a recommendation for substitutions but only as a means of determining approximate dimensional equivalents. Page General 1 Design Consideration 2 Metr
14、ic-Inch Related Sizes 2 Threads 3 Thread Tolerances 3 Material 3 Property Class 3 Color Coding 3 Method of Designation 3 Policy for Selecting Parts for New Design 3 Service Parts Substitution Policy 4 Width Across Flats 4 Thickness 4 Tops and Bearing Surfaces 4 Corner Fill 5 True Position of Tapped
15、Hole 5 Countersink 5 Threads 5 Nut Identification 5 Material and Physical Properties 5 Finish 5 Restricted Chemical Substances 5 Surface Discontinuities 5 Dimension 6 Part List 6 Technical Information 6 NUMBER: MPAPS S-EM-1.101-GS/PL TITLE: Hex Nuts Metric Series REVISION: 1506 This document is rest
16、ricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2015 by Navistar, Inc. JUNE 2015 Page 3 of 6 Metric Series Approximate Metric Series Approximate mm Inch Series mm Inch Series
17、 3 3 #4, #5 16 5/8 3 4 #6, #8 18 3 5 #10 20 3/4 3 6 1/4 22 7/8 3 8 5/16 24 1 3 10 3/8, 7/16 27 1 3 12 1/2 30 1-1/8, 1-1/4 3 14 9/16 36 1-1/2 5.0 THREADS: The ISO basic profile is essentially the same geometric configuration as the unified screw thread basic form. The threads will be coarse series, t
18、olerance class 6H. 6.0 THREAD TOLERANCES: The medium ISO class of fit 6H(Int)/6g(Ext) is approximately the same as the 2A(Ext)/2B(Int) allowance in the U.S. unified thread series for comparable size. For example: Thread Allowance M10 x 1.5 6H(Int)/6g(Ext) 0.032 mm (.00126 in) 3/8 16 UNC 2A(Ext)/2B(I
19、nt) 0.0013 in (0.033 mm) 7.0 MATERIAL: Proof and tensile strength values are listed in section 22.0 Nuts will not be used for special applications such as those requiring weld ability, corrosion resistance, or ability to withstand temperatures above 300 C or below minus 50 C. 8.0 PROPERTY CLASS: The
20、 property class designation for steel nuts is equal to one-hundredth of the approximate proof load stress in megapascals (1 MPa = 1 N/mm2). 9.0 COLOR CODING: Not recommended, except in cases where adequate insurance is needed to prevent mixing of “metric parts“ with look-alike “inch parts.“ The colo
21、r blue is standard identifier used in some industries. This must be handled internally at individual plants where needed and is meant to be supplemental to the normal finish and easily deleted when the need for supplemental identification no longer exists. The supplemental blue color should not be u
22、sed on material such as stainless steel which is specified for cosmetic purposes, or phosphate coating which may cause a loss of color identity. 10.0 METHOD OF DESIGNATION: Hex nuts are designated by the following data, preferably in the sequence shown: product name, nominal diameter, steel property
23、 class or material identification, special feature, if any, finish and part number as shown in the following examples: Hex Nut, M10, Class 10, PHC, Part Number Hex Nut, M10, Class 10, Left Hand Threaded, ZN8F, Part Number NOTE: It is common practice in ISO standards to omit thread pitch from the pro
24、duct size designation when screw threads are the metric coarse thread series. e.g., M10 is M10 x 1.5. 11.0 POLICY FOR SELECTING PARTS FOR NEW DESIGN: Approved parts are so designated to reduce variety of parts and assure maximum availability, interchangeability and cost savings. For new design, part
25、s shall be selected from “Approved“ part list only. NUMBER: MPAPS S-EM-1.101-GS/PL TITLE: Hex Nuts Metric Series REVISION: 1506 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume
26、 all patent liability. 2015 by Navistar, Inc. JUNE 2015 Page 4 of 6 Nominal Sizes: 3, 4, and 5 (Class 5 only, Zinc Trivalent) 6, 8, 10, 12, 16, 20, 24, 30 and 36. Material: Class 5 (Sizes 3, 4, and 5 only). Class 10 (Sizes 6 thru 36). Finish: Zinc Trivalent (ZN8F) for Class 5 nuts, machine screw app
27、lications. Phosphate Coating (PHC) for Class 10 Nuts. 12.0 SERVICE PARTS SUBSTITUTION POLICY: In the event that engineering does not indicate a “Do not substitute“ in engineering specifications, the following substitutions may be implemented in service. This policy is the result of a proposal circul
28、ated April 20, 1981 and subsequently approved by engineering departments worldwide. Hex Nuts (Metric Series) To Be Replaced Service Replacement Class 8 Material with Plain Finish Class 10 Material with Phosphate Coated (PHC) Finish Class 10 Material with Plain Finish Class 10 Material with Phosphate
29、 Coated (PHC) Finish 13.0 WIDTH ACROSS FLATS: The width across flats will be the distance, measured perpendicular to the axis of the nut, between two opposite wrenching flats. Regardless of nut material or manufacturing process, no transverse section through the nut between 25 and 75 percent of the
30、actual nut thickness as measured from the bearing surface will be less than the minimum width across flats specified in table on last page. Maximum width across flats will not be exceeded, except that for milled-from-bar nuts made of non-ferrous materials the specified maximum width across flats may
31、 be exceeded to conform with the commercial tolerances of cold finished bar stock material. For milled-from-bar nuts, the nominal bar size used will be the closest commercially available size to, but not greater than, the specified maximum width across flats of the nut. 14.0 THICKNESS: The nut thick
32、ness will be the overall distance, measured parallel to the axis of the nut, from the top of the nut to the bearing surface, and will include the thickness of the washer face where provided, but will exclude raised identification markings, where they are permitted. 15.0 TOPS AND BEARING SURFACES: M1
33、6 and smaller nuts will be double chamfered. M20 and larger nuts, at the manufacturers option, will be either double chamfered or have a washer faced bearing surface and a chamfered top. The diameter of the bearing surface will not exceed the width across flats nor be less than the bearing face diam
34、eter specified in table on last page. For referee purposes, measurement of washer face diameter on washer faced nuts will be taken at mid thickness of the washer face. The bearing surface will be flat and perpendicular to the axis of the thread with the total runout limit specified in table on last
35、page. The tops of washer faced nuts will be flat and the diameter of the chamfer circle will be equal to the maximum width across flats within a tolerance of minus 15 percent. The length of chamfer at hex corners will be from 5 to 15 percent of the nominal thread diameter. The surface of the chamfer
36、 may be slightly convex or rounded. NUMBER: MPAPS S-EM-1.101-GS/PL TITLE: Hex Nuts Metric Series REVISION: 1506 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liab
37、ility. 2015 by Navistar, Inc. JUNE 2015 Page 5 of 6 16.0 CORNER FILL: A rounding or lack of fill at the junction of hex corners with the chamfer will be permissible provided the width across corners is within specified limits at and beyond a distance equal to 17.5 percent of the nominal thread diame
38、ter from the chamfered face. 17.0 TRUE POSITIONS OF TAPPED HOLE: The axis of tapped hole will be located at true position with respect to the axis of nut body within a tolerance zone having a diameter equivalent to 4 percent of the maximum width across flats, regardless of feature size. 18.0 COUNTER
39、SINK: The tapped hole will be countersunk on the bearing face(s). The countersink included reference angle will be 90 degrees to 120 degrees. The maximum countersink diameter will be 1.15 times the nominal thread diameter (major diameter) for nuts M4 and smaller, the nominal thread diameter plus 0.7
40、5 mm for nuts M5 through M8, and 1.08 times the nominal thread diameter for M10 and larger nuts. The minimum countersink diameter will be the nominal thread diameter. 19.0 THREADS: Thread form, diameters and associated pitches are in accordance with ISO recommendations. Thread will be made to the to
41、lerances for the medium class of fit (6H - internal threads) as shown in EM-15 and ISO 965/2, General Purpose Metric Screw Threads. 20.0 NUT IDENTIFICATION: Refer to MPAPS F-31, Part II. 21.0 MATERIAL AND PHYSICAL PROPERTIES: Steel Classes 51, 8, and 10, in accordance with MPAPS F-31, Part II. Stain
42、less steel (SST-304) will be type 304 per MPAPS A-37. 22.0 FINISHES: Nuts will be furnished plain, plated or coated in accordance with the MPAPS and class listed below. Plain (PLN) Free from dirt and rust and coated with a light oil film. Zinc Trivalent plus Sealer (ZN8F) MPAPS G-20, Class 8F. Phosp
43、hate Coated (PHC) MPAPS G-1, Class B-2. 23.0 RESTRICTED CHEMICAL SUBSTANCES: Effective January 1, 2007, all product supplied to the requirements of this specification must comply with the requirements of the MPAPS B-50 specification. 24.0 SURFACE DISCONTINUITIES: Surface discontinuities will be dete
44、rmined by methods shown in MPAPS F-31. Part II 1For sizes below 6 mm (Machine Screw applications) NUMBER: MPAPS S-EM-1.101-GS/PL TITLE: Hex Nuts Metric Series REVISION: 1506 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technic
45、al Standards. Suppliers are required to assume all patent liability. 2015 by Navistar, Inc. JUNE 2015 Page 6 of 6 25.0 DIMENSIONS: Dimensions in millimeters: Nominal Size M3 M4 M5 M6 M8 M10 M12 M14* M16 M18* M20 M22* M24 M27* M30 M36 S Width Across Flats, Max Min 5.50 5.32 7.00 6.78 8.00 7.78 10.00
46、9.78 13.00 12.73 16.00 15.73 18.00 17.73 21.00 20.67 24.00 23.67 27.00 26.48 30.00 29.16 34.00 33.00 36.00 35.00 41.00 40.00 46.00 45.00 55.00 53.80 E Width Across Corners, Max Min 6.40 6.01 8.10 7.66 9.24 8.79 11.55 11.05 15.01 14.38 19.60 17.77 21.90 20.03 25.40 23.35 27.70 26.75 31.20 29.90 34.64
47、 32.95 37.29 41.60 39.55 47.30 45.20 53.12 50.85 63.51 60.79 M Thickness, Max Min 2.40 2.15 3.20 2.90 4.70 4.40 5.20 4.90 6.80 6.44 8.40 8.04 10.80 10.37 12.80 12.10 14.80 14.10 15.40 14.60 18.00 16.90 19.40 18.10 21.50 20.20 22.70 21.30 25.60 24.30 31.00 29.40 DW Bearing Face Diameter,Min 4.6 5.9 6
48、.9 8.9 11.6 14.6 16.6 19.6 22.5 24.3 27.7 31.4 32.5 36.9 42.7 50.8 Total Runout of Bearing Surface FIM, Max - - 0.30 0.33 0.36 0.39 0.42 0.45 0.48 0.52 0.56 0.60 0.64 0.71 0.76 0.89 Coarse Thread Pitch, Nom 0.5 0.7 0.8 1 1.25 1.5 1.75 2 2 2.5 2.5 2.5 3 3 3.5 4 Minor Diameter, Max 2.599 3.422 4.334 5
49、.153 6.912 8.676 10.441 12.21 14.21 15.744 17.744 19.744 21.252 24.252 26.771 32.27 Min 2.459 3.242 4.134 4.917 6.647 8.376 10.106 11.835 13.835 15.294 17.294 19.294 20.752 23.752 26.211 31.67 Pitch Diameter, Max (Ref) 2.775 3.663 4.605 5.50 7.348 9.206 11.063 12.913 14.913 16.600 18.600 20.600 22.316 25.316 28.007 33.702 Pitch Diameter, Min (Ref) 2.675 3.545 4.48 5.35 7.188 9.026 10.863 12.701 14.
