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 11 1.0 GENERAL: Machine screw and tooth lock washer assemblies
2、 are general purpose fasteners for mass production and other operations where speed and convenience are paramount factors. 2.0 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
3、 specification. 3.0 CONTENTS: Page General 1 Restricted Chemical Substances 2 Machine Screw Specifications 2 Body Diameter 2 Washer Manufacturing Detail 2 Spring Lock Washer Manufacturing Detail 2 Assembly Detail 2 Flushness 2 Washer Material 2 Washer Temper Test 3 Washer Spread Test 3 Finishes 3 De
4、fects 3 Policy for Selecting Parts for New Design 3 Flat Head Cross Recess Machine Screws External Tooth Lock Washer Assemblies 4 Pan Head Cross Recess Machine Screws and External Tooth Lock Washer 5 Hexagon Head Machine Screws and External Tooth Lock Washer Assemblies 6 Pan Head Cross Recess Machin
5、e Screws and Spring Lock Washer Assemblies 7 Fillister Head Machine Screws and Spring Lock Washer Assemblies Hexagon Head Machine Screws and Spring Lock Washer Assemblies 8 10 Technical Information 11 NAVISTAR, INC. Material, Parts, and Process Specifications (MPAPS) NUMBER: MPAPS S-C-10.101-GS/PL F
6、ormer Designation: ESP-C-10.101-GS TITLE: Machine Screws and Lock Washer Assemblies English Series-Not Recommended (Noun Code 7450) CURRENT REV No.: 1506 DATE: June 2015 WRITTEN/EDITED BY: Materials Engineering APPROVED BY: Materials Engineering SUPERSEDES: ESP-C-10.101-GS - August 2006 PRINTED COPI
7、ES 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 p
8、ractices and to determine the applicability of regulatory limits prior to use. Change Notice: Changed to New MPAPS format; Combined GS, PP, NPP. NUMBER: MPAPS S-C-10.101-GS/PL TITLE: Machine Screws and Lock Washer Assemblies REVISION: 1506 This document is restricted and may not be sent outside Navi
9、star, 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 11 4.0 MACHINE SCREW SPECIFICATIONS: The General Specifications in MPAPS S-C-1.101-GS/PL will apply with additional requir
10、ements as indicated below. 5.0 BODY DIAMETER: The minimum limit for unthreaded shank diameter will be the minimum pitch diameter specified in dimensional tables. The maximum limit will be as described in the paragraph covering assembly detail. 6.0 WASHER MANUFACTURING DETAIL: At purchasers option, t
11、he external and internal tooth lock washers may be either of the two types illustrated in the cuts. The number of teeth, the length of teeth, the width of rim and the thickness over the teeth (free height) will be optional with the manufacturer, with the provision, however, that the washers are symm
12、etrical in shape and that the projection of the teeth on both sides of the washer is uniform within a tolerance equal to one-half of the projection on one side. The extrusion of a slight collar at the inside diameter of the countersunk external tooth lock washers will also be optional with the manuf
13、acturer. 7.0 SPRING LOCK WASHER MANUFACTURING DETAIL: The section of finished washers will be slightly trapezoidal in shape with the thickness at the inner periphery greater than the thickness at outer periphery by an amount varying from a minimum of .0005 inch to a maximum of .001 inch per .0156 (1
14、/64) inch of minimum section width. The minimum washer thickness specified in the dimensional tables represents the nominal mean thickness of the trapezoid. The tolerance on the nominal mean thickness of the trapezoid will be plus .006 inch for size #12 and smaller and plus .010 inch for sizes 1/4 t
15、hrough 3/8. Washers will be coiled so that the free height is approximately twice the thickness of washer section. The gap and relationship of severed ends will be such as to insure that washers will compress flat. The flat faces and the inner washers will compress flat. The flat faces and the inner
16、 and outer peripheries will be smooth and free from knurling, serrations, die marks, deep scratches, etc., although slight feed roll marks will be permissible. 8.0 ASSEMBLY DETAIL: Washers will be assembled on headed screw blanks before the threads are rolled, - the inside diameter of the washers an
17、d the diameter of the unthreaded portion of the screws being of a size which will permit free rotation of the washers and yet prevent their disassembly from the screws. 9.0 FLUSHNESS: The value for “V“ specified in the dimensional tables for flat and oval head screw and washer assemblies will apply
18、when the assembly is seated. These dimensions can be checked by screwing a screw and washer assembly into a hardened steel block having an 80-82 degree countersunk hole. 10.0 WASHER MATERIAL: Tooth lock washers will be fabricated from SAE 1050-1066 steel and heat treated to a Rockwell hardness of 40
19、-50 C scale or equivalent. It is recommended, however, that the lighter, more sensitive depth reading Rockwell A scale be used when testing hardness of washers having thin section. Precautions must be taken to avoid the effects of decarburization when making hardness tests. Washers will meet the tes
20、t requirements of this standard. Spring lock washers will be fabricated from SAE 1060 steel or equivalent, 5-7 grain size, capable of being hardened in oil, free from surface defects, and not below average in cleanliness. The wire will meet the decarburization limits specified in the following table
21、: NUMBER: MPAPS S-C-10.101-GS/PL TITLE: Machine Screws and Lock Washer Assemblies 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
22、Navistar, Inc. JUNE 2015 Page 3 of 11 Diameter of Round Wire (Or Sections of Equivalent Area) Average Depth of Total Decarburization Max (Free ferrite) Av. Total Affected Depth Max (Free ferrite plus partial decarburization) Up to .140 incl .002 .006 Over .140 to .250, incl .003 .008 11.0 WASHERS TE
23、MPER TEST: Washers will be set down or deflected a distance equivalent to 1/3 turn of a coarse thread nut of corresponding size. The free height of the washer on release will be at least 5/6 of original free height. 12.0 WASHER SPREAD TEST: Washers will be removed from screw and the rim of the washe
24、r will be cut or severed with a cold chisel or cutting pliers. The severed ends will be gripped by pliers or vise and pliers. Separation of the ends in the form of a helix, to a distance equal to the inside diameter of the washer, will not result in fracture. When the ends are separated a greater di
25、stance and the washer fractures, the fracture at the point of fracture will show a fine grain, and the washer up to the instant of fracture will deliver a tough, springy reaction. 13.0 FINISHES: Finish specifications in MPAPS S-C-1.101-GS/PL will apply. 14.0 DEFECTS: Screw and washer assemblies will
26、 be free from all defects which might affect their serviceability. 15.0 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 in volume buying. For new design, parts shall be selecte
27、d from “Approved“ part list only. Head Types: Flat, Oval, Pan, Hex Drive: Cross Recess, ANSI Type 1 (Phillips) and Hex Diameters: 6, 8, 10, 1/4, 5/16, 3/8 Threads: Coarse Finishes: Zinc Trivalent, Class 6A (ZN6A), Phosphate Coated (PHC) Lengths: As shown below: Nominal Size Length 6 8 10 1/4 5/16 3/
28、8 1/8 1/4 3/8 1/2 5/8 APPROVED PARTS 3/4 7/8 Length Preferred Sizes 1 Up to 1 Inch 1/8 Inch Increments 1-1/4 Over 1 Inch to 1-1/2 Inches 1/4 Inch Increments 1-1/2 Over 2-1/2 Inches to 3 Inches 1/2 Inch Increments 1-3/4 2 2-1/4 2-1/2 3 NUMBER: MPAPS S-C-10.101-GS/PL TITLE: Machine Screws and Lock Was
29、her Assemblies 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 4 of 11 16.0 FLAT HEAD CROSS RECESS M
30、ACHINE SCREWS EXTERNAL TOOTH LOCK WASHER ASSEMBLIES: Dimensions in inches: Nominal SizeB K E M L H V X THREAD DETAIL Driver SizeThreadsPer Inch Head Diameter Head Height Recess Diameter Recess Width Recess Depth Penetration Gaging Depth Radius Under Head Flush with Minus Tolerance of Washer Thicknes
31、s Pitch Diameter (See Gen Specs) Max Sharp Min Sharp Abs Min Max Ref Min Max Min Min Max Min Max Max Max Min Max Min Basic 6 32 .279 .257 .244 .083 .161 .174 .029 .083 .106 .072 .095 .055 .026 .020 .016 .1169 .1141 .1177 2 * 6 40 .279 .257 .244 .083 .161 .174 .029 .083 .106 .072 .095 .055 .026 .020
32、.016 .1210 .1184 .1218 2 8 32 .332 .308 .292 .100 .176 .189 .030 .098 .121 .087 .110 .066 .030 .020 .016 .1428 .1399 .1437 2 * 8 36 .332 .308 .292 .100 .176 .189 .030 .098 .121 .087 .110 .066 .030 .020 .016 .1452 .1424 .1460 2 10 24 .385 .359 .340 .116 .191 .204 .032 .113 .136 .102 .125 .076 .036 .0
33、25 .019 .1619 .1586 .1629 2 * 10 32 .385 .359 .340 .116 .191 .204 .032 .113 .136 .102 .125 .076 .036 .025 .019 .1688 .1658 .1697 2 * 12 24 .438 .410 .389 .132 .255 .268 .035 .133 .156 .116 .139 .086 .041 .025 .019 .1879 .1845 .1889 3 * 12 28 .438 .410 .389 .132 .255 .268 .035 .133 .156 .116 .139 .08
34、6 .041 .025 .019 .1918 .1886 .1928 3 1/4 20 .507 .477 .452 .153 .270 .283 .036 .148 .171 .131 .154 .100 .047 .025 .019 .2164 .2127 .2175 3 * 1/4 28 .507 .477 .452 .153 .270 .283 .036 .148 .171 .131 .154 .100 .047 .025 .019 .2258 .2225 .2268 3 5/16 18 .635 .600 .568 .191 .352 .365 .061 .194 .216 .174
35、 .196 .125 .060 .028 .023 .2752 .2712 .2764 4 * 5/16 24 .635 .600 .568 .191 .352 .365 .061 .194 .216 .174 .196 .125 .060 .028 .023 .2843 .2806 .2854 4 3/8 16 .762 .722 .685 .230 .380 .393 .065 .223 .245 .203 .226 .150 .072 .034 .028 .3331 .3287 .3344 4 * 3/8 24 .762 .722 .685 .230 .380 .393 .065 .22
36、3 .245 .203 .226 .150 .072 .034 .028 .3468 .3430 .3479 4 * Non-Preferred Sizes and Threads 16.1 Part List: 16.1.1 Approved: * Header Point Nominal Size-TPI Length Finish Material Part Number 1/4 -20 5/8 ZN6A CST 191983 * 3/8 -16 1 ZN6A CST 24668R1 NUMBER: MPAPS S-C-10.101-GS/PL TITLE: Machine Screws
37、 and Lock Washer Assemblies 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 5 of 11 17.0 PAN HEAD CR
38、OSS RECESS MACHINE SCREWS AND EXTERNAL TOOTH LOCK WASHER: Dimensions in inches: Nominal SizeB K E M L H P Q W X THREAD DETAIL Driver SizeThreadsPer Inch Head Diameter Head Height Recess Dia. Recess Width Recess Depth Penetration Gaging Depth Head Radius Head Radius Radius Under Head Washer Outside D
39、ia. Washer Thickness Pitch Diameter (See Gen Specs) Max Min Max Min Min Max Min Min Max Min Max Ref. Min Max Max Min Max Min Max Min Basic * 4 40 .219 .205 .080 .070 .109 .122 .019 .060 .078 .053 .071 .173 .010 .017 .230 .220 .020 .012 .0950 .0925 .0958 1 * 4 48 .219 .205 .080 .070 .109 .122 .019 .0
40、60 .078 .053 .071 .173 .010 .017 .230 .220 .020 .012 .0978 .0954 .0985 1 * 5 40 .245 .231 .089 .079 .145 .158 .028 .057 .083 .046 .072 .191 .015 .019 .255 .245 .020 .014 .1080 .1054 .1088 2 * 5 44 .245 .231 .089 .079 .145 .158 .028 .057 .083 .046 .072 .191 .015 .019 .255 .245 .020 .014 .1095 .1070 .
41、1101 2 6 32 .270 .256 .097 .087 .153 .166 .028 .066 .091 .055 .080 .207 .015 .021 .285 .270 .020 .014 .1169 .1141 .1177 2 * 6 40 .270 .256 .097 .087 .153 .166 .028 .066 .091 .055 .080 .207 .015 .021 .285 .270 .020 .014 .1210 .1184 .1218 2 8 32 .322 .306 .115 .105 .169 .182 .030 .082 .108 .071 .097 .
42、244 .015 .025 .320 .305 .023 .018 .1428 .1399 .1437 2 * 8 36 .322 .306 .115 .105 .169 .182 .030 .082 .108 .071 .097 .244 .015 .025 .320 .305 .023 .018 .1452 .1424 .1460 2 10 24 .373 .357 .133 .122 .186 .199 .031 .100 .124 .089 .113 .284 .020 .028 .381 .365 .024 .018 .1619 .1586 .1629 2 * 10 32 .373
43、.357 .133 .122 .186 .199 .031 .100 .124 .089 .113 .284 .020 .028 .381 .365 .024 .018 .1688 .1658 .1697 2 * 12 24 .425 .407 .151 .139 .246 .259 .034 .115 .141 .098 .124 .323 .025 .032 .410 .395 .027 .020 .1879 .1845 .1889 3 * 12 28 .425 .407 .151 .139 .246 .259 .034 .115 .141 .098 .124 .323 .025 .032
44、 .410 .395 .027 .020 .1918 .1886 .1928 3 1/4 20 .492 .473 .175 .162 .268 .281 .036 .135 .161 .118 .144 .373 .035 .038 .510 .494 .028 .023 .2164 .2127 .2175 3 * 1/4 28 .492 .473 .175 .162 .268 .281 .036 .136 .161 .118 .144 .373 .035 .038 .510 .494 .028 .023 .2258 .2225 .2268 3 5/16 18 .615 .594 .218
45、.203 .337 .350 .059 .169 .193 .149 .173 .527 .040 .047 .610 .588 .034 .028 .2752 .2712 .2764 4 * 5/16 24 .615 .594 .218 .203 .337 .350 .059 .169 .193 .149 .173 .527 .040 .047 .610 .588 .034 .028 .2843 .2806 .2854 4 3/8 16 .740 .716 .261 .244 .376 .389 .065 .210 .233 .190 .213 .652 .040 .056 .760 .74
46、0 .040 .032 .3331 .3287 .3344 4 * 3/8 24 .740 .716 .261 .244 .376 .389 .065 .210 .233 .190 .213 .652 .040 .056 .760 .740 .040 .032 .3468 .3430 .3479 4 *Non-Preferred Sizes and Threads 17.1 Part List: 17.1.1 Approved: * Header Point Nominal Size-TPI Length Finish Material Part Number * 10 -24 1/2 ZN6
47、A CST 20880R1 1/4 -20 5/8 ZN6A CST 272475 1/4 -20 7/8 ZN6A CST 455344 * 10 -32 1/2 ZN6A CST 191680 NUMBER: MPAPS S-C-10.101-GS/PL TITLE: Machine Screws and Lock Washer Assemblies REVISION: 1506 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission fr
48、om Corporate Technical Standards. Suppliers are required to assume all patent liability. 2015 by Navistar, Inc. JUNE 2015 Page 6 of 11 18.0 HEXAGON HEAD MACHINE SCREWS AND EXTERNAL TOOTH LOCK WASHER ASSEMBLIES: Dimensions in inches: Nominal Size B K P E R W X THREAD DETAIL ThreadsPer Inch Head Width
49、 Width Across Corners Head Height Radius Under Head Washer Outside Diameter Washer Thickness Pitch Diameter (See Gen Specs) Max Min Min Max Min Max Max Min Max Min Max Min Basic * 4 40 .219 .213 .238 .060 .049 .017 .230 .220 .020 .014 0950 .0925 .0958 * 4 48 .219 .213 .238 .060 .049 .017 .230 .220 .020 .014 0978 .0954 .0985 * 5 40 .250 .244 .272 .070 .058 .019 .255 .245 .020 .016 1080 .1054 .1088 * 5 4
