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 8 NAVISTAR, INC. Material, Parts, and Process Specifications
2、(MPAPS) NUMBER: MPAPS S-CM-28.101-GS/PL Former Designation: ESP-CM-28.101-GS TITLE: Hex Socket Head Cap screws Metric Series CURRENT REV No.: 1506 DATE: June 2015 WRITTEN/EDITED BY: Materials Engineering APPROVED BY: Materials Engineering SUPERSEDES: ESP-CM-28.101-GS - October 2013 PRINTED COPIES OF
3、 THIS 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 practi
4、ces and to determine the applicability of regulatory limits prior to use. Change Notice: Changed to New MPAPS format; Combined GS, GI, PP. 1.0 GENERAL: This standard may differ in some respects with certain segments of ISO and national standards. In recognition of these possible differences, the siz
5、es and tolerance ranges used were established in an effort to enable the use of commercially available items, dimensionally interchangeable worldwide. The specification contains the essentials of the following standards: International Organization for Standardization: ISO 861, 885, 888, 965, and 476
6、2 British Standards Institute: BS 4168 German Institute of Standardization: DIN 912 Standards Association of Australia: AS 1420 ASME/ANSI: B18.3.1M The inclusion of dimensional data is not intended to imply that all the capscrews described are stock production sizes. Inch dimensioned standard capscr
7、ews may be found in MPAPS S-C-28.101-GS/PL. 2.0 CONTENTS: Page General 1 Design Consideration 2 Metric-Inch Related Sizes 2 Threads 2 Thread Tolerances 2 Thread Length Formula 3 Property Class 3 Color Coding 3 Method of Designation 3 Policy for Selecting Parts for New Design 3 Heads 3 NUMBER: MPAPS
8、S-CM-28.101-GS/PL TITLE: Hex Socket Head Cap screws 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 liability. 2015 by Navistar, Inc. JUNE 2015 Page
9、2 of 8 3.0 DESIGN CONSIDERATION: Coarse thread series only will be considered as part of this standard, because of the following advantages: Resists nicking and has less tendency to cross thread. Load and stress concentrations on threads are lower. Less likely to be seriously affected by manufacturi
10、ng errors such as decarburization and oversize minor diameter of internal threads. Hex socket head capscrews are suitable for use only in conditions of limited clearancence. Hex socket head capscrews are interchangeable with flanged 12-point screws. Because of larger gripping surface which permits b
11、etter wrenching, 12-point screws from 10 mm size and up are preferred over hex socket head capscrews. 4.0 METRIC-INCH RELATED SIZES: During the 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 recom
12、mendation for substitutions but only as a means of determining approximate equivalents. Metric Series mm Approximate Inch Series 3 #4, #5 4 #6, #8 6 1 /4 8 5/16 Metric Series mm Approximate Inch Series 10 3/8, 7/16 12 1/ 2 16 9/16, 5/8 20 3/4 5.0 THREADS: The ISO basic profile is essentially the sam
13、e geometric configuration as the unified screw thread basic form. The threads will be coarse series, tolerance class 6g. Class 5g6g is an acceptable alternate for class 12.9 as specified in ISO 4762. 6.0 THREAD TOLERANCES: The medium ISO class of fit 6H(Int)/6g(Ext) is approximately the same as the
14、2A(Ext)/2B(Int) allowance in the U.S. unified thread series for comparable size. For example: Page Socket 4 Point 4 Position of Head to Shank 4 Length 5 Threads 5 Thread Length 5 Marking 5 Material Decarburization Finishes Restricted Chemical Substances Surface Discontinuities 5 5 6 6 6 Hex Socket H
15、ead Capscrews 6 Technical Information 8 NUMBER: MPAPS S-CM-28.101-GS/PL TITLE: Hex Socket Head Cap screws 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 pa
16、tent liability. 2015 by Navistar, Inc. JUNE 2015 Page 3 of 8 Thread Allowance M10 x 1.5 6H (Int) / 6g (Ext) 0.032 mm (.00126 in) 3/8 16 UNC 2A (Ext) / 2B (Int) .0013 in (0.033 mm) 7.0 THREAD LENGTH FORMULA: The thread lengths shown in section 25.0 are based on the formulas shown below: Dimensions in
17、 millimeters: Nominal Length Formula for Thread Length Over To - 125 2d + 6 125 200 2d + 12 200 - 2d + 25 D = Nominal Diameter of the Screw 8.0 PROPERTY CLASS: The property class designation symbol for hex socket head capscrews consists of two parts, the first is approximately one-hundredth of the m
18、inimum tensile strength in megapascals (MPa) and the second is one-tenth of the ratio between the minimum yield stress and the minimum tensile strength, expressed as a percentage. The multiplication of the figures will approximate 1/10 the minimum yield stress in megapascals (1 MPa = 1 N/mm2). 9.0 C
19、OLOR CODING: Not recommended, except in cases where adequate insurance is needed to prevent mixing of “metric parts“ with look-alike “inch parts.“ The color blue is standard identifier used in some industries. This must be handled internally at individual plants where needed and is meant to be suppl
20、emental to the normal finish and easily deleted when the need for supplemental identification no longer exists. The supplemental blue color should not be used on finishes such as chromium bright which are specified for cosmetic purposes, or phosphate coating which causes a loss of color identity. 10
21、.0 METHOD OF DESIGNATION: Hex socket head capscrews will be designated by size, length, word description, material, finish, and part number as shown in the following example. M8 x 20, Hex Socket Head Capscrew, Class 12.9, PHC, Part Number The absence of a specification for pitch indicates that coars
22、e thread s required; e.g., a coarse thread of the dimensions M10 x 1.5 is designated as “M10.” 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, parts shal
23、l be selected from “Approved“ part list only. Material: Class 12.9 Finish: Plain (PLN) Phosphate Coated (PHC) NUMBER: MPAPS S-CM-28.101-GS/PL TITLE: Hex Socket Head Cap screws REVISION: 1506 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from
24、Corporate Technical Standards. Suppliers are required to assume all patent liability. 2015 by Navistar, Inc. JUNE 2015 Page 4 of 8 Dimensions in millimeters: Nominal sizes and Length Incrementation: Lengths Nominal Sizes M3 M4 M5 M6 M8 M10 M12 M16 M20 M24 6 x 8 x x 10 x x x x 12 x x x x USE FLANGED
25、12 POINT SCREWS IN MPAPS S-CM-29.101-GS/PL FOR THESE SIZES 16 x x x x x 20 x x x x x 25 x x x x 30 x x x x 35 x x x 40 x x x 45 x x 50 x x 60 x x 70 x 12.0 HEADS: Unless otherwise specified, knurling on heads will be optional with the manufacturer providing the diameter across the tops of the knurl
26、and the diameter of the head before knurling or of the unknurled portion are within the tabulated maximum and minimum head diameter limits, respectively. The minimum head diameter will be measured on the side of the head adjacent to the chamfer or rounding at periphery of bearing face. Top: The top
27、of heads will be flat, perpendicular to the axis of the screw and chamfered or rounded at the periphery and will not exceed the values listed for R1in the table on the last page of this specification. Edge: The edge between the bearing surface and the side of the head may be chamfered or rounded wit
28、hin the tabulated limits of R in the table on the last page of this specification. Concentricity: The head will be concentric with the shank within 1 percent of the basic screw diameter or 0.15 mm full indicator movement (FIM) whichever is greater. 13.0 SOCKET: Where hexagon sockets are chamfered or
29、 relieved, the depth of chamfer or relief will not exceed the equivalent of 7.5 percent of the nominal socket size. The broached sockets which are at or near the maximum limit of size, the overcut resulting from pre-drilling will not exceed 20 percent of the length of any flat of the socket on sizes
30、 up to and including 20 mm. Socket will be concentric with respect to the axis of screw within a tolerance zone having a diameter equal to three percent of the basic screw diameter or 0.13 mm, whichever is greater, for screws up to and including 12 mm, and of a diameter equal to 6 percent of the bas
31、ic screw diameter for larger screw sizes. 14.0 POINT: The point will be flat and either chamfered 45 degrees to a depth slightly below the root of the thread, or a radius approximately equal to 1.4 times the nominal diameter. Chamfer of screw sizes up to and including 4 mm diameter, and for screw le
32、ngths up to 75 percent of the diameter will be optional. 15.0 POSITION OF HEAD TO SHANK: Positional relationship of head to shank on screws will be such that screws will meet the limits in dimensional chart. NUMBER: MPAPS S-CM-28.101-GS/PL TITLE: Hex Socket Head Cap screws REVISION: 1506 This docume
33、nt 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 5 of 8 16.0 LENGTH: The length of capscrews will be measured in a line paralle
34、l to the axis of the screw from the bearing surface of the head to the plane of flat of the point. The tolerance on screw length will be as tabulated below. Nominal Length Tolerance Over 6 thru 10 0.29 Over 10 thru 18 0.35 Over 18 thru 30 0.42 Over 30 thru 50 0.5 Over 50 thru 80 0.6 Over 80 thru 120
35、 0.7 Over 120 thru 180 0.8 Over 180 thru 250 0.93 Over 150 thru 300 1.05 17.0 THREADS: Thread form, diameters, and associated pitches are in accordance with ISO Standards. Threads will be made to the tolerances for the medium class of fit (6g) as shown in ISO 965/2 General Purpose Metric Screw Threa
36、ds. Threads with tolerance class 5g6g are an acceptable alternate for class 12.9 as specified in ISO 4762. All sizes and all lengths up to either 10 x the diameter or 150 mm long will be roll threaded. Lengths which exceed 10 x the diameter or 150 mm long may be rolled, cut or ground. 18.0 THREAD LE
37、NGTH: The length of thread will be the distance from the end of the screw, including any chamfer or radius to the leading face of a screw ring gauge which has been screwed as far as possible onto the screw by hand. See the page 6 of this document for standard thread lengths. Screws that are too shor
38、t for minimum thread lengths as shown on the last page of this document will be threaded to permit a screw ring gage being screwed by hand to within a distance from the underside of the head not exceeding two and one half times the pitch for all diameters. 19.0 MARKING: At the option of the manufact
39、urer, hexagon socket capscrews above 5 mm diameter will have the strength grade designation (12.9) permanently marked, preferably by indenting on the side of the head. The manufacturers identification may also be shown. 20.0 MATERIAL: Class 12.9 (alloy steel). Capscrews will be fabricated from an al
40、loy steel having one or more of the following alloying elements: chromium nickel, molybdenum, or vanadium, in sufficient quantity to assure that the specified hardness range of Rockwell 38 to 45 HRc at the surface for sizes up to and including 6 mm, and Rockwell 37 to 45 HRc for all sizes over 6 mm
41、is met. Screws will be hardened by quenching from the austenitizing temperature and tempered not lower than 345 C. Stainless Steel, Type 18-8 (SST-304) per MPAPS A-37. Stainless steels will be *passivated per MPAPS A-37 Type 5. 21.0 DECARBURIZATION: No gross decarburization is permitted on Class 12.
42、9 products. For partial decarburization limits, refer to dimensional chart. NUMBER: MPAPS S-CM-28.101-GS/PL TITLE: Hex Socket Head Cap screws REVISION: 1506 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Sup
43、pliers are required to assume all patent liability. 2015 by Navistar, Inc. JUNE 2015 Page 6 of 8 22.0 FINISHES: Capscrews will be plain, plated or coated in accordance with the Navistar, Inc. Corporate Engineering Material Specification and class listed below. Zinc Trivalent (ZN6A) MPAPS G-20, Class
44、 6A. Phosphate Coating (PHC) MPAPS G-1, Class B-2. Zinc Aluminum Clear (ZACLR) - MPAPS G-4518, Type 1. High tensile strength steel components such as capscrews, are more susceptible to embrittlement by hydrogen, therefore, electroplating is not recommended for these products. However, if chemical or
45、 electrochemical surface coating cannot be avoided, the plated capscrew must be heated at a temperature sufficiently high and for a period sufficiently long to remove the hydrogen 23.0 RESTRICTED CHEMICAL SUBSTANCES: Effective January 1, 2007, all product supplied to the requirements of this specifi
46、cation must comply with the requirements of the MPAPS B-50 specification. 24.0 SURFACE DISCONTINUITIES: Surface discontinuities will be determined by methods shown in MPAPS F-31, Part 1. 25.0 HEX SOCKET HEAD CAP SCREWS: Dimensions in millimeters: * Non-Preferred Sizes M3 M4 M5 * M6 M8 M10 * M12 * M1
47、6 * M20 * A Body Diameter 3 4 5 6 8 10 12 16 20 B Body Transition Diameter 3.6 4.7 5.7 6.8 9.2 11.2 14.2 18.2 22.4 C Head Diameter min max min max min max min max min max min max min max min max min max DIN 912 (1983) 5.32 5.68 6.78 7.22 8.28 8.72 9.78 10.22 12.73 13.27 15.73 16.27 17.73 18.27 23.67
48、 24.33 29.67 30.33 ISO 4762 (1997) 5.32 5.68 6.78 7.22 8.28 8.72 9.78 10.22 12.73 13.27 15.73 16.27 17.73 18.27 23.67 24.33 29.67 30.33 ASME/ANSI B18.3.1M 5.32 5.50 6.80 7.00 8.27 8.50 9.74 10.00 12.70 13.00 15.67 16.00 17.63 18.00 23.58 24.00 29.53 30.00 D Head Height min max min max min max min max min max min max min max min max min max DIN 912 (1983) 2.86 3.00 3.82 4.00 4.82 5.00 5.70 6.00 7.64 8.00 9.64 10.00 11.57 12.00 15.57 16.00 1
