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-32.101-GS/PL Former Designation: ESP-CM-32.101-GS TITLE: Headless Hex Socket Set Screws Metric series CURRENT REV No.: 1506 DATE: June 2015 WRITTEN/EDITED BY: Materials Engineering APPROVED BY: Materials Engineering SUPERSEDES: ESP-CM-32.101-GS - August 2006 PRINTED COPIES
3、OF 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 prac
4、tices 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: Implementation of this standard must be in accordance with the policies and procedures outlined in MPAPS S-A-1.101. There may also be supplemental
5、 group 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 differences, the sizes and tolerance ranges used were established in an effort to enable
6、the use of commercially available items, dimensionally interchangeable worldwide. This specification contains the essentials of the following standards. International Organization for standardization: ISO 2343, 8262, 8888, and 8965/II. British Standards Institute: BS 4168 German Institute of Standar
7、dization: DIN 914, DIN 916 Standards Association of Australia: AS 1421 American National Standards Institute: ANSI B18.3.6M-1979 The inclusion of dimensional data is not intended to imply that all the set screws described are stock production sizes. Inch dimensioned standard socket set screws may be
8、 found in MPAPS S-C-32.101-GS/PL. 2.0 CONTENTS: Page General 1 Design Consideration 2 Metric-Inch Related Sizes 2 Threads 2 Thread Tolerances 3 Color Coding 3 Method of Designation 3 Application Data 3 NUMBER: MPAPS S-CM-32.101-GS/PL TITLE: HEADLESS HEX SOCKET SET SCREWS REVISION: 1506 This document
9、 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 2 of 8 3.0 DESIGN CONSIDERATION: In order to prevent future proliferation of set
10、 screws, one head form (Hex Socket) and two points (Cup and Half Dog) will be considered preferred. The following considerations should be given in selection of a point. Cup Point: Most widely used and readily available point in the U.S. Allows quick alignment of gears, collars and pulleys on shafts
11、, when the cutting action of the point is not objectionable. Screws in this standard are minimum Rockwell C 45 and can be used on shafts with a surface hardness up to Rockwell C 35 without deforming the point. Half Dog Point: Recommended for use with hardened members and on hollow tubing provided so
12、me locking feature holds screw in place. Requires an additional operation of drilling a hole in a shaft which must match the point diameter to prevent side play. Also applied where permanent location of one part in relation to another is desired. 4.0 METRIC-INCH RELATED SIZES: During the inch to met
13、ric design transition period, the following chart of elated 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. Metric Series mm Approximate Inch Series Metric Series m
14、m Approximate Inch Series 3 #4, #5 10 3/8 4 #6, #8 12 1/ 2 5 #10 16 9/16, 5/8 6 #12, 1/ 4 20 3/ 4 8 5/16 24 7/8, 1 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, tolerance class 6g. Thread
15、with tolerance class 5g6g is an acceptable option. Page Policy for Selecting Parts for New Design 3 Sockets 4 Points 4 Length 4 Threads 5 Material Finish Restricted Chemical Substances Workmanship 5 6 6 6 Cup Point 7 Half Dog Points 7 Part List 8 Technical Information 8 NUMBER: MPAPS S-CM-32.101-GS/
16、PL TITLE: HEADLESS HEX SOCKET SET 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 3 of 8 6.0
17、THREAD TOLERANCES: The medium 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(Int) .0013 in (0.033 mm) 7
18、.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 color blue is standard identifier used in some industries. This must be handled internally at individual plants where needed and is meant to be s
19、upplemental 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 material such as stainless steel which is specified for cosmetic purposes, or phosphate coating which may cause a loss of color identi
20、ty. 8.0 METHOD OF DESIGNATION: Hexagon socket set screws will be designated by size, length, description, type of point, material, finish, and part number. M8 x 25, Hex Socket Screw Set, Cup Point, Steel, Plain, Part Number The absence of a specification for pitch indicates that coarse thread is req
21、uired; e.g., a coarse thread of the dimensions M10 x 1.5 is designated as “M10.“ 9.0 APPLICATION DATA: The following is published as guide only. Because conditions differ widely, it may be necessary to modify seating torques somewhat to suit a particular application conditions. The advisability and
22、the extent of such modifications can best be determined by experiment in the particular assembly environment. Dimensions in millimeters: Nominal Size Recommended Seating Torque* Tap Drill Size mm N.m Inch-lbs M3 0.6 5 2.5 M4 2 18 3.3 M5 4 35 4.2 M6 7 62 5 M8 17 150 6.75 Nominal Size Recommended Seat
23、ing Torque* Tap Drill Size mm N.m Inch-lbs M10 34 300 8.5 M12 60 530 10.25 M16 150 1325 14 M20 300 2650 17.5 M24 475 4200 21 * Not applicable to screws with a length equal to or less than the diameter 10.0 POLICY FOR SELECTING PARTS FOR NEW DESIGN: Approved parts are so designated to reduce variety
24、of parts and assure maximum availability, interchangeability, and cost savings. For new design, parts shall be selected from “Approved“ part list only. Nominal Sizes: M3, M4, M5, M6, M8, M10, M12, M16, M20, and M24 Material: Steel Finish: Plain (PLN) and Phosphate Coating (PHC) Lengths: See chart be
25、low. NUMBER: MPAPS S-CM-32.101-GS/PL TITLE: HEADLESS HEX SOCKET SET 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 Navista
26、r, Inc. JUNE 2015 Page 4 of 8 Dimensions in millimeters: Nominal Screw Length Nominal Screw Size M3 M4 M5 M6 M8 M10 M12 M16 M20 M24 5 x 6 x x 8 x x x x 10 x x x x x 12 x x x x x 16 x x x x x x 20 x x x x x x 25 x x x x x x 30 x x x x x x x 35 x x x x x x 40 x x x x x x 45 x x x x x 50 x x x x x 60 1
27、1.0 SOCKETS: The face will have the outer edge chamfered at 30/45 to slightly below the root diameter of the thread. The symmetry of the hexagon socket across flats relative to the major diameter of the screw thread, will not exceed the values given on pages 5 and 6. The datum will be a point along
28、the screw as close as practicable to a distance one diameter from the hexagon socket end of the screw. For broached sockets which are at or near the maximum across flats dimension, the overcut resulting from drilling a pilot hole in the socket will not exceed 20 percent of the length of any flat of
29、the hexagon socket. BROACHED SOCKET 12.0 POINTS: The point angle for cup point screws will apply only to the portion of the angle which lies below the root diameter of the thread. A slight rounding or flat is permissible at the apex of the cup. Cup points may be supplied either plain or internally o
30、r externally knurled. The end of half dog points will be flat and the outer edge may be broken with a small chamfer or radius. The half dog point will be concentric with respect to the major diameter of the screw thread to within the values given on page 6. The datum will be a point along the screw
31、as close as practicable to a distance one diameter from the end of the screw thread nearest to the half dog point. 13.0 LENGTH: The nominal length for screws with all types of points will be the overall length including the point and the chamfer at the socket end. The preferred nominal lengths in as
32、sociation with standard nominal diameters are given in the table on the preceding page. The tolerances on length are given in the table below: NUMBER: MPAPS S-CM-32.101-GS/PL TITLE: HEADLESS HEX SOCKET SET SCREWS REVISION: 1506 This document is restricted and may not be sent outside Navistar, Inc. o
33、r 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 Dimension in millimeters: Nominal Length Tolerance ( ) Over Thru 3 6 0.2 6 10 0.29 10 18 0.35 18 30 0.42 30 50 0.5 50 80 0.6 14.0 TH
34、READS: Thread form, diameters, and associated pitches are in accordance with ISO Recommendations for coarse pitch series. Threads will be made to the tolerances of the medium class of fit (6g) for plain or unplated screws as shown in ISO 8965/II, General Purpose Metric Screw Threads. Threads with to
35、lerance class 4g6g are an acceptable option. 15.0 MATERIAL: Carbon Steel or Alloy Steel. Hardness: The surface hardness at the point will be equal to or greater than the core hardness and both will be minimum 45 Rc. Hardness Testing: The core hardness will be determined on a longitudinal section as
36、close as practicable to a position at mid-radius and one diameter from the point end of the screw. Decarburization: There will be no evidence of decarburization on the points of the screws and both gross and Partial decarburization in the screw thread will be limited to the extent shown below. Torqu
37、e Test: Hex socket set screws will conform to the torque requirements given in the table below when tested as follows: 1. Finished screws will be inserted in a test block as shown in the illustration below until the top surface of the screw face is flush with the test block and the point bears on a
38、firm base, e.g., a socket head capscrew screwed in from the other side. 2. Using the applicable hexagon wrench key engaging the full depth of the socket of the set screw, the screw will withstand the tightening torques given in the table below of torque requirements without reaming the socket or cra
39、cking the screw. NUMBER: MPAPS S-CM-32.101-GS/PL TITLE: HEADLESS HEX SOCKET SET 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. 201
40、5 by Navistar, Inc. JUNE 2015 Page 6 of 8 TORQUE REQUIREMENTS 16.0 FINISH: The normal stock finish for set screws is plain (blue-black oxide color) as an adherent film from heat treatment plus a residual coating of light oil. Other finishes will be in accordance with the Navistar Engineering Materia
41、l Specification and class listed below: Zinc Trivalent (ZN6A) MPAPS G-20, Class 6A Phosphate Coating (PHC) MPAPS G-1, Class B-2. High tensile strength steel components such as set screws, are more susceptible to embrittlement by hydrogen, therefore, electroplating is not recommended for these produc
42、ts. However, if chemical or electrochemical surface coating cannot be avoided, the plated set screw must be heated at a temperature sufficiently high and for a period sufficiently long to remove the hydrogen. 17.0 RESTRICTED CHEMICAL SUBSTANCES: Effective January 1, 2007, all product supplied to the
43、 requirements of this specification must comply with the requirements of the MPAPS B-50 specification. 18.0 WORKMANSHIP: Set screws will be clearly finished, free from burrs and any other defects that might affect their serviceability. Nominal Diameter Minimum Length of Screw for Test ( mm) Inspecti
44、on Torque N m, Min Cup Half Dog Point Point M3 4 5 1.0 M4 5 6 2.1 M5 5 8 4.7 M6 6 8 7.7 M8 8 10 17.8 M10 10 12 35 M12 12 16 57 M16 16 20 126 M20 25 25 252 M24 25 30 420 NUMBER: MPAPS S-CM-32.101-GS/PL TITLE: HEADLESS HEX SOCKET SET SCREWS REVISION: 1506 This document is restricted and may not be sen
45、t 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 7 of 8 19.0 CUP POINT: Dimensions in Millimeters: Nom. Screw Dia Nom Pitch B Socket Details D L E B C Symmetry Of
46、 Socket FIM* Nom Socket Size Socket Across Flats Socket Across Corners Point Diameter Screw Length Depth of Key Engagement Max Min Max Min Max Max Min Min Min M3 0.5 1.5 1.54 1.51 1.77 1.71 0.2 1.4 1.1 4 2.1 M4 0.7 2 2.05 2.02 2.35 2.28 0.24 2 1.7 5 2.3 M5 0.8 2.5 2.56 2.52 2.92 2.84 0.24 2.5 2.2 6
47、2.7 M6 1 3 3.07 3.02 3.5 3.4 0.24 3 2.7 6 3 M8 1.25 4 4.08 4.02 4.66 4.55 0.3 5 4.7 8 4 M10 1.5 5 5.08 5.02 5.82 5.69 0.3 6 5.7 10 5 M12 1.75 6 6.09 6.02 6.98 6.85 0.36 8 7.6 12 6 M16 2 8 8.11 8.03 9.29 9.15 0.36 10 9.6 16 8 M20 2.5 10 10.13 10.03 11.6 11.45 0.42 14 13.5 25 10 M24 3 12 12.15 12.03 1
48、3.91 13.7 0.42 16 15.5 30 12 * FIM = Full Indicator Movement 20.0 HALF DOG POINTS: NUMBER: MPAPS S-CM-32.101-GS/PL TITLE: HEADLESS HEX SOCKET SET 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. 201
