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 5 1.0 GENERAL: This standard conforms essentially with the Ame
2、rican National Standard, ANSI B 18.6.2 and SAE Standard J 102 for Square Head Set Screws. 2.0 CONTENTS: Page General 1 Policy for Selecting Parts for New Design 1 Service Parts Substitution Policy 2 Design Consideration 2 Length 2 Threads 2 Length of Thread 2 Material 3 Finishes 3 Restricted Chemica
3、l Substances 3 Points 3 Workmanship 3 Dimensions 4 Part List 5 Technical Information 3.0 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
4、 shall be selected from “Approved“ part list only. NAVISTAR, INC. Material, Parts, and Process Specifications (MPAPS) NUMBER: MPAPS S-C-34.101-GS/PL Former Designation: ESP-C-34.101-GS TITLE: Square Head Set Screws- English Series (Noun Code 7450) CURRENT REV No.: 1506 DATE: June 2015 WRITTEN/EDITED
5、 BY: Materials Engineering APPROVED BY: Materials Engineering SUPERSEDES: ESP-C-34.101-GS - August 2006 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
6、all of the safety issues associated with its use. The user is responsible to consult appropriate safety and health practices 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-34.101-GS/PL TITLE: S
7、quare Head 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 2 of 5 Sizes: 10, 1/4, 5/16, 3
8、/8, 1/2, 5/8, 3/4 or 1 Point: Cup Length Incrementation: Thread: UNC 2A Over 1/2 to 1 inch = 1/8 Material: Steel (STL) Over 1 to 2 inches = 1/4 Finish: Zinc Trivalent, Class 6A (ZN6A), and Phosphate Coating (PHC) Over 2 inches = 1/2 4.0 SERVICE PARTS SUBSTITUTION POLICY: In the event that engineerin
9、g 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 circulated April 20, 1981, and subsequently approved by engineering departments worldwide. Square Head Set Screws To Be Replaced
10、 Service Replacement Plain (PLN) Finish Zinc Trivalent, Class 6A (ZN6A) finish or phosphate coating (PHC) finish (if ZN6A equivalent is not set up for service) 5.0 DESIGN CONSIDERATION: To insure the validity of a single part number for two material strengths, application design must be to the case
11、hardened set screws. 6.0 LENGTH: Length of square head set screws will be measured from the bottom of the head to the extreme point in a line parallel to the axis of the screw. The tolerance on screw length will be as tabulated below: 7.0 THREADS: Threads will be Unified Standard, Class 2A, UNC or U
12、NF series or UNRC or UNRF series with radius root, optional with manufacturer. Class 2A limits will apply to plain finish (unplated or uncoated) screws and to plated or coated screws before plating or coating. For screws with additive finish the maximum diameters of Class 2A may be exceeded by the a
13、mount of the allowance, that is, the basic diameters (the Class 2A maximum diameters plus the allowance) will apply to plated or coated screws after plating or coating. The major diameter of plated or coated screws may approach but will not be less than the Class 2A minimum limit. Since standard gag
14、es provide only for lengths of engagement up to 1-1/2 diameters, changes in pitch diameter of either or both external or internal thread may be required for longer lengths of engagement. 8.0 LENGTH OF THREAD: Square head set screws will have complete (full form) threads extending over that portion o
15、f the screw length that is not affected by the point. For the respective head constructions, threads will extend to the conical underside of head, to within one thread (as measured with a non-chamfered or non-counterbored standard thread ring gage) from the flat Size Range Length Tolerance Up to 1 i
16、nch, incl Over 1 inch to 2 inches, incl Over 2 inches 10 to 5/8 -.03 -.06 -.09 3/4 to 1-1/2 -.06 -.12 -.18 NUMBER: MPAPS S-C-34.101-GS/PL TITLE: Square Head Set Screws REVISION: 1506 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporat
17、e Technical Standards. Suppliers are required to assume all patent liability. 2015 by Navistar, Inc. JUNE 2015 Page 3 of 5 underside of the head, or into the neck relief. Threads through angular or crowned portions of points will have fully formed roots with partial crests. 9.0 MATERIAL: AISI or SAE
18、 1010-1020 steel, case hardened, Class 2B (for sizes to and including 3/8 inch diameter), or Class 3 (for sizes 7/16 inch diameter and larger) per CEMS A-40; or medium carbon steel, quenched and tempered to Rockwell C35-40. 10.0 FINISH: As designated by part number, parts will be furnished plain, pl
19、ated or coated in accordance with the Navistar Engineering Material Specification and class listed below. Zinc Trivalent, Class 6A (ZN6A) MPAPS G-20, Class 6A. Phosphate Coated (PHC) MPAPS G-1, Class B2. 11.0 RESTRICTED CHEMICAL SUBSTANCES: Effective January 1, 2007, all product supplied to the requ
20、irements of this specification must comply with the requirements of the MPAPS B-50 specification. 12.0 POINTS: As specified part number, screws will have Cone, Cup, Dog, Half Dog or Oval points conforming to the dimensions tabulated. Half dog points will apply on dog point screws where screw length
21、is less than sum of the nominal diameter and dog point length. The point angles specified will apply only to those portions of the angles which lie below the minor diameter of the thread, it being recognized that the angle may vary in the threaded portion due to manufacturing process. Dimensions in
22、inches: A Y A Y A Y Nominal Size Cone Point Angle 118 2 For Length Below and Shorter 90 2 For Longer Lengths Nominal Size Cone Point Angle 118 2 For Length Below and Shorter 90 2 For Longer Lengths Nominal Size Cone Point Angle 118 2 For Length Below and Shorter 90 2 For Longer Lengths 10 3/16 3/8 3
23、/8 5/8 5/8 12 7/32 7/16 7/16 3/4 3/4 1/4 1/4 1/2 1/2 7/8 7/8 5/16 5/16 9/16 9/16 1 1 On cone points, the truncation or rounding at the apex of cone will not exceed the equivalent of 10 percent of the basic screw diameter. On dog and half-dog points, the point will be located at true position with re
24、spect to the axis of the thread within a tolerance zone having a diameter equal to 6 percent of the basic screw diameter or .010 inch for nominal screw sizes up to and including 3/4 inch, or .020 inch for larger screw sizes, whichever is smaller; regardless of feature size. Cup points furnished by s
25、ome manufacturers may be externally or internally knurled. 13.0 WORKMANSHIP: Set Screws will not contain imperfections which affect usability or serviceability such as excessive amounts of burrs, seams, laps, loose scale or irregular surfaces. NUMBER: MPAPS S-C-34.101-GS/PL TITLE: Square Head Set Sc
26、rews 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 5 14.0 DIMENSIONS: Dimensions in inches: N
27、ominal Size 10 1/4 5/16 3/8 7/16 X Undercut Diameter, Max .145 .185 .240 .294 .345 Undercut Diameter, Min .140 .170 .225 .279 .330 W Head Width, Max .188 .2500 .3125 .3750 .4375 Head Width, Min .180 .241 .302 .362 .423 S Across Corners, Max .265 .354 .442 .530 .619 Across Comers, Min .247 .331 .415
28、.497 .581 H Head Thickness, Max .148 .196 .245 .293 .341 Head Thickness, Min .134 .178 .224 .270 .315 J Head Radius .48 .62 .78 .94 1.09 K Undercut Radius, Max .027 .032 .036 .041 .046 M Undercut Width, Max .083 .100 .111 .125 .143 N Point Diameter, Max .102 .132 .172 .212 .252 Point Diameter, Min .
29、088 .118 .156 .194 .232 P Point Diameter, Max .127 .156 .203 .250 .297 Point Diameter, Min .120 .149 .195 .241 .287 Q Point Length .005 .090 .125 .156 .188 .219 Q1 Point Length .005 .045 .063 .078 .094 .109 R Point Radius .142 .188 .234 .281 .328 Y Cone Point Angle Varies According to Length - See T
30、abulated Chart on page 1. B Threads Per Inch Pitch Dia, Max Pitch Dia, Min Pitch Dia, Basic 14 .1619 .1586 .1629 32* .1688 .1658 .1697 20 .2164 .2127 .2175 28* .2258 .2225 .2268 18 .2752 .2712 .2764 24 * .2843 .2806 .2854 16 .3331 .3287 .3344 24* .3468 .3430 .3479 14 * .3897 .3850 .3911 20* .4037 .3
31、995 .4050 * Non-Preferred NUMBER: MPAPS S-C-34.101-GS/PL TITLE: Square Head 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
32、5 by Navistar, Inc. JUNE 2015 Page 5 of 5 Dimensions in inches: Nominal Size 1/2 9/16 5/8 3/4 7/8 1 X Undercut Diameter, Max .400 .454 .507 .620 .731 .838 Undercut Diameter, Min .385 .439 .492 .605 .716 .823 W Head Width, Max .5000 .5625 .6250 .7500 .8750 1.0000 Head Width, Min .484 .545 .606 .729 .
33、852 .974 S Across Corners, Max .707 .795 .884 1.060 1.237 1.414 Across Corners, Min .665 .748 .833 1.001 1.170 1.337 H Head Thickness, Max .389 .437 .485 .582 .678 .774 Head Thickness, Min .361 .407 .452 .544 .635 .726 J Head Radius 1.25 1.41 1.56 1.88 2.19 2.50 K Undercut Radius, Max .050 .054 .059
34、 .065 .072 .081 M Undercut Width, Max .154 .167 .182 .200 .222 .250 N Point Diameter, Max .291 .332 .371 .450 .530 .609 Point Diameter, Min .270 .309 .347 .425 .502 .579 P Point Diameter, Max .344 .391 .469 .563 .656 .750 Point Diameter, Min .334 .379 .456 .549 .642 .734 Q Point Length .250 .281 .31
35、3 .375 .438 .500 Q1 Point Length .125 .140 .156 .188 .219 .250 R Point Radius .375 .422 .469 .562 .656 .750 Y Cone Point Angle Varies According to Length - See Tabulated Chart on page 1. B Threads Per Inch Pitch Dia, Max Pitch Dia, Min Pitch Dia, Basic 13 .4485 .4435 .4500 20* .4662 .4619 .4675 12*
36、.5068 .5016 .5084 18* .5250 .5205 .5264 11 .5644 .5589 .5660 18* .5875 .5828 .5889 10 .6832 .6773 .6850 16* .7079 .7029 .7094 9* .8009 .7946 .8028 14* .8270 .8216 .8286 8 .9168 .9100 .9188 14 .9519 .9463 .9536 * Non Preferred 15.0 PART LIST: 15.1 Approved: 16.0 TECHNICAL INFORMATION: For further inf
37、ormation related to the technical content of this specification, contact: Suppliers may purchase controlled copies of this specification by contacting: Materials Engineering and Technology Dept. 10400 W. North Avenue Melrose Park, IL 60160 E-mail: MaterialsEngineeringN IHS Global Inc. 15 Inverness Way East Englewood CO 80112-5776 Phone: 1-800-854-7179 E-mail: AutomotiveIHS.com Website: http:/ Nominal Size-TPI Length Point Type Finish Part Number 1/4 -20 1 CUP ZN6A 107345 3/8 -16 1 1/2 OVAL PLN 102458 3/4 -10 3 1/4 CUP PHC 12436R1
