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-EM-70.101-GS/PL Former Designation: ESP-EM-70.101-GS TITLE: Multi-Thread Wide Range “U” 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-70.101-GS - Septembe
3、r 2000 PRINTED COPIES 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
4、safety and health practices 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-0.101. There ma
5、y also be supplemental group instructions in regard to use of metric standards that should be taken into account. The metric wide range U-shape multi-thread spring nuts covered in this standard are intended for applications where it is desired to use spring nuts in conjunction with bolts, machine sc
6、rews or screw and washer assemblies. Nuts conforming to this standard are suitable for use with mating fasteners conforming to 9.8 or lower property classes. 2.0 RESTRICTED CHEMICAL SUBSTANCES: Effective January 1, 2007, all product supplied to the requirements of this specification must comply with
7、 the requirements of the MPAPS B-50 specification. 3.0 CONTENTS: Page General 1 Restricted Chemical Substances 1 Design Consideration 2 Metric-Inch Related Sizes 2 Threads 2 Thread Tolerances 3 Property Class 3 Color Coding 3 Method of Designation 3 Policy for Selecting Parts for New Design 3 Identi
8、fication 3 Contours 3 Extruded Barrel 3 Retaining Extrusion 3 NUMBER: MPAPS S-EM-70.101-GS/PL TITLE: Multi-Thread Wide Range “U” Nuts REVISION: 1506 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers a
9、re required to assume all patent liability. 2015 by Navistar, Inc. JUNE 2015 Page 2 of 8 4.0 DESIGN CONSIDERATION: In general, U shape nuts are preferred to J shape nuts for standardization purposes due to their superior retention capabilities and the complete support they provide around the hole in
10、 the panel. Nuts conforming to this standard are suitable for use with mating metric fasteners having class 9.8 or lower strength levels. The proof strengths of these nuts are equivalent to the tensile strengths of class 9.8 male fasteners; however, proof strengths are somewhat lower than class 9 he
11、x nuts. The maximum installation torques must be adjusted accordingly. Multi-Thread Wide Range “U“ Nuts are available in short and long throat styles, to cover variations in throat depth requirements. Nut styles will be selected to best suit the edge distances and panel thicknesses of the applicatio
12、n. To assure proper function and performance of spring nuts, to provide flexibility for changing nut designs and to achieve simplification, it is essential that the panel hole sizes, edge to center distances and any embossing or punching features necessary be kept in conformance with the assembly co
13、nsiderations in section 20.0. 5.0 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 recommendation for substitutions but only as a means of determining approxima
14、te dimensional equivalents. Metric Series mm Approximate Inch Series 4 #6, #8 5 #10 6 1/4 8 5/16 10 3/8, 7/16 6.0 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 6H. Threads in t
15、he extruded barrel will be produced only by the roll forming process and will conform to ISO Class 6H internal metric screw threads. However, the minor diameter may exceed the specified maximum limit providing the nut will meet the proof strength requirements. Page Material 4 Finishes 4 Relief of Em
16、brittlement 4 Performance Requirements 4 Assembly Considerations 5 Workmanship 6 Dimensions 7 Part List 8 Technical Information 8 NUMBER: MPAPS S-EM-70.101-GS/PL TITLE: Multi-Thread Wide Range “U” Nuts REVISION: 1506 This document is restricted and may not be sent outside Navistar, Inc. or reproduce
17、d without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2015 by Navistar, Inc. JUNE 2015 Page 3 of 8 7.0 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. unifi
18、ed 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) 8.0 PROPERTY CLASS: The property class designation for steel nuts is equal to one-hundredth of the approximate proof load stress in mega
19、pascals (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 color blue is standard identifier used in some industries. This must be handled internally at individual plants where
20、 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 used on finishes such as chromium bright which are specified for cosmetic purposes or phosphate coating which may
21、cause a loss of color identity. 10.0 METHOD OF DESIGNATION: Nuts will be designated by size, word description, throat, finish, material, and part number as follows: M10, Multi-Thread Wide Range “U“ Nut, Short, PHC, HTS, Part Number The absence of a specification for pitch indicates the coarse thread
22、 is 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 shall be sel
23、ected from “Approved“ part list only. Nominal sizes: All sizes listed Throat style: Short Finish: Phosphate coated (PHC) 12.0 IDENTIFICATION: Spring nuts will be permanently and legibly marked with manufacturers identification on the upper surface of the top leg adjacent to the fold. The marking wil
24、l have a minimum height of 1.6 mm. 13.0 CONTOURS: Contours of features such as upper leg in area of extruded barrel, the barrel, retaining extrusion, cutoff, and carrying tab will be optional with the manufacturer, provided the specified dimensions are maintained and nuts will meet all of the perfor
25、mance requirements. 14.0 EXTRUDED BARREL: The axis of the extruded barrel will be located centrally on the width of the upper leg within a tolerance of plus or minus 0.25 mm. 15.0 RETAINING EXTRUSION: The nut retaining extrusion in the bottom leg will conform to the dimensions shown in the illustrat
26、ion and Table below, and otherwise be such as to enable the nuts to meet the performance requirements. The critical edges of the extrusion will be free from burrs which could cause interference as spring nut is assembled on to panel. The size, configuration and location of the hole through the retai
27、ning extrusion will be such that a bolt or screw or respective NUMBER: MPAPS S-EM-70.101-GS/PL TITLE: Multi-Thread Wide Range “U” Nuts REVISION: 1506 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers
28、are required to assume all patent liability. 2015 by Navistar, Inc. JUNE 2015 Page 4 of 8 size when installed normal to the plane of the lower leg into the nut, assembled on a test plate as described in the performance requirement of this document, will not interfere with the sides of the hole. DIME
29、NSIONS OF RETAINING EXTRUSION (mm) Nominal Nut Size Q R S T U V Cap Opening Radius Radius Width Flat Width Bend Depth Max Max Min 0.5 0.2 Max Min 0.5 M4 0.5 2 1 0.8 7 1 0 2 M5 0.5 2 1 0.8 7.8 1 0 2 M6 0.7 2 1 0.8 9.4 1 0 2.3 M8 0.7 2.8 1.8 1 10.8 1 0 2.5 M10 1.4 3.6 2.5 1.3 14.2 1.3 0.3 3.3 16.0 MAT
30、ERIAL: Nuts will be fabricated from 1050-1065 steel per MPAPS A-0, Part I, and heat treated to meet the performance requirements of this standard. Nuts will have a hardness of Rockwell C45 to 50. (For stock thickness less than 1 mm, it is recommended the hardness be checked using the appropriate sup
31、erficial Rockwell scale and converted to Rockwell C.) 17.0 FINISHES: Nuts will be supplied in accordance with the Navistar Engineering Material Specification and class listed below. Phosphate coated (PHC) - G-1, Class B-2. 18.0 RELIEF OF EMBRITTLEMENT: Plated or coated steel nuts which are subject t
32、o hydrogen embrittlement will be suitably treated subsequent to the plating or coating operation to relieve such embrittlement. 19.0 PERFORMANCE REQUIREMENTS: Preassembly and Retention Test: Spring nuts will preassemble onto test panels of thickness equal to the two extremes of the panel ranges spec
33、ified, having minimum diameter holes located at the maximum edge distance (see Recommended Assembly Data table). The retaining extrusion will snap into the hole and, when nuts are so assembled, a pull force of 13 N minimum, applied parallel to the axis of nut, will be required to remove the nut from
34、 the panel. Proof Load Test: The spring nut will be prepared for testing by removing the lower leg and bend portion at rear. The actual barrel height “K“ will be measured and recorded. The upper portion of nut along with special bushings will be assembled onto the test bolt, as depicted below, then
35、installed into a suitable tension text fixture. The bushings will be made from SAE 1095 steel, hardened and tempered to a hardness of Rockwell C59 to 62, and will conform to the dimensions NUMBER: MPAPS S-EM-70.101-GS/PL TITLE: Multi-Thread Wide Range “U” Nuts REVISION: 1506 This document is restric
36、ted 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 shown below. The test bolt will have threads conforming to Class 6g tolerances for e
37、xternal metric screw threads and will be of 9.8 steel or higher property class. Following application and removal of the respective tension load specified in the table below, the threaded barrel portion of nut will exhibit no indication of thread stripping or rupture and the bolt will be capable of
38、being removed from the nut barrel with the fingers. The height of barrel will be remeasured and any reduction reflecting permanent set of the base of barrel will not exceed the maximum limitation given in the table below. The nut will be reinstalled on the test bolt and subjected to the respective p
39、roof load specified in the table below, then released. There will be no evidence of cracks in the barrel or upper leg of nut. The threaded portion of barrel will withstand this proof load without thread stripping, excessive plastic deformation or rupture, and the bolt will be removable from nut with
40、 the fingers. (Occasionally, it may be necessary to manually wrench the bolt to initiate motion, and such practice will be considered permissible only if the bolt can be removed with the fingers following an initial loosening of not more than one-half turn of the bolt.) Additional distortion occurri
41、ng in the upper leg and the base of barrel will be permissible. Dimensions in millimeters: Nominal Size Test Tension Load kN Allowable Permanent Set Max Test Proof Load kN A X Test Bushing Counter bore Diameter Test Bushing Hole Diameter Min Max Min Max M4 5.70 0.25 7.90 8.0 8.3 5.0 5.3 M5 9.30 0.35
42、 12.78 8.7 9.1 6.0 6.3 M6 13.06 0.45 18.09 9.9 10.2 7.0 7.3 M8 23.80 0.50 32.94 11.5 11.8 8.5 9.0 M10 37.70 0.70 52.20 14.7 15.0 10.5 11.0 20.0 ASSEMBLY CONSIDERATIONS: To assure proper function and satisfactory performance of spring nuts and to provide flexibility for possible subsequent substituti
43、ons in designs, it is essential that the panel hole sizes, edge to center dimensions, and any embossing or slotting of panels necessary to install the nut be designed in accordance with the recommendations set forth in the illustrations and table below. NUMBER: MPAPS S-EM-70.101-GS/PL TITLE: Multi-T
44、hread Wide Range “U” Nuts 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 6 of 8 RECOMMENDED ASSEMBL
45、Y DATA Dimensions in millimeters: Nominal Thread Size Throat Style A B C D E F G Edge Distance Panel Hole Diameter Nut Length Clearance Slot Width Slot or Emboss Width (Flat) * Emboss Depth Emboss Depth Max Min Max Min Min * Max Min Min * Min * Min* M4 Short 9 8 8.3 7.5 18 15 14 13 2.5 1 Long 13 12
46、23 M5 Short 10.5 9.5 9.1 8.3 20.5 16 15 14 2.5 1.1 Long 15.5 14.5 26.5 M6 Short 12.5 11.5 10.7 9.9 25 16.5 15.5 15 2.5 1.2 Long 18.5 17.5 31.5 M8 Short 13.5 12.5 12.1 11.3 26.5 20 19 17.5 2.5 1.4 Long 20 19 33.5 M10 Short 17.5 16.5 15.5 14.7 35 26 25 25 3 2 Long 27.5 26.5 45 * Consideration should b
47、e given to tolerances of manufacturing practices used to emboss and punch these features when designing panels in which they are employed. * Dimension measured between centers of corner radii. 21.0 WORKMANSHIP: Nuts will be free from cracks, splits, burrs, loose scale, and any defects that might affect their serviceability. NUMBER: MPAPS S-EM-70.101-GS/PL TITLE: Multi-Thread Wide Range “U” Nuts 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 assum
