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. 2016 by Navistar, Inc. APRIL 2016 Page 1 of 21 1.0 GENERAL: This standard conforms in all essentials with
2、 the SAE Standard and the American National Standard for Slotted and Cross Recess Head Tapping Screws. 2.0 CONTENTS: NAVISTAR, INC. Material, Parts, and Process Specifications (MPAPS) NUMBER: MPAPS S-D-1.101-GS/PL Former Designation: ESP-D-1.101-GS TITLE: Slotted and Cross Recess Tapping Screws- Eng
3、lish Series Not Recommended (Noun Code 7450) CURRENT REV No.: 1604 DATE: April 2016 WRITTEN/EDITED BY: W. Cook APPROVED BY: R. Goluch SUPERSEDES: 1506- June 2015 PRINTED COPIES OF THIS DOCUMENT MUST BE VERIFIED FOR CURRENT REVISION This specification may involve hazardous materials, equipment, and p
4、rocedures. 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 practices and to determine the applicability of regulatory limits prior to use. Change Notice: Corrections to 32.1 Parts List T
5、able, editorial changes Page General 1 Screw Types and Application 2 Height of Head 3 Bearing Surface 3 Depth of Recess 3 Slot Depth 3 Eccentricity 3 Length 3 Spaced Threads 4 Machine Screw Diameter-Pitch Threads 4 Length of Thread 4 Short Length Screws 5 Points 7 Diameter of Body 7 Materials 7 Fini
6、shes 8 Restricted Chemical Substances Hole For Assembly 8 8 Performance Requirement and Test 8 Assembly Considerations 8 Policy for Selecting Parts for New Design 8 Defects 9 Flat Head Cross Recess Tapping Screws-Type AB, B, BP and BT 9 NUMBER: MPAPS S-D-1.101-GS/PL TITLE: Slotted and Cross Recess T
7、apping Screws REVISION: 1604 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. 2016 by Navistar, Inc. APRIL 2016 Page 2 of 21 3.0 SCREW TYPES AND APPLICATI
8、ONS: Screws covered by this standard include tapping screws of both the thread forming and thread cutting varieties. The type designations, descriptions and applications are as follows: 3.1 Thread Forming Tapping Screws: Thread Forming Tapping screws are generally for application in materials where
9、large internal stresses are permissible or desirable to increase resistance to loosening. They will be of the following types: Type AB (Preferred): Type AB tapping screws will have spaced threads, with same pitches as Type B, and a gimlet point. They are primarily intended for use in thin metal, res
10、in impregnated plywood, and asbestos compositions. Type B (Non-Preferred): Type B tapping screws will have spaced threads and a blunt point with incomplete entering threads. Type BP (Non-Preferred): Type BP tapping screws will have spaced threads the same as Type B but will have a conical point exte
11、nding beyond the incomplete entering threads. They are intended for piercing fabrics or in assemblies where holes may be misaligned. Type C (Non-Preferred): Type C tapping screws will have threads of machine screw diameter-pitch combinations approximating Unified Form with a blunt point and tapered
12、incomplete entering threads. Type C tapping screws are not subject to thread gaging but will meet dimensions specified in this standard. They are intended for application where the use of a machine screw pitch thread is preferable to the use of the spaced thread types of thread forming screws, or wh
13、ere chips from machine screw pitch thread cutting screws are objectionable. It should be recognized that in specific applications, involving long thread engagement or hard materials, this type of screw may require extreme driving torques. 3.2 Thread Cutting Tapping Screws: Thread cutting tapping scr
14、ews are generally for application in materials where disruptive internal stresses are undesirable or where excessive driving torques are encountered with thread forming screws. They will be of the following types: Types D, F, and T (Preferred): Types D, F, and T tapping screws will have threads of m
15、achine screw diameter-pitch combinations approximating Unified Form with a blunt point and tapered entering threads having one or more cutting edges and chip cavities. The tapered threads of the Type F screw may be complete or incomplete at the manufacturers option; all other types will have incompl
16、ete tapered threads. Types D, F, and T tapping screws are not subject to thread gaging but will meet Page Flat Head Cross Recess Tapping Screws-Type C, D, F and T 10 Oval Head Cross Recess Tapping Screws-Type AB, B, BP and BT 11 Oval Head Cross Recess Tapping Screws-Type C, D, F and T 12 Pan Head Cr
17、oss Recess Tapping Screws-Type AB, B, BF, BP and BT 13 Pan Head Slotted Tapping Screws-Type AB, B and BT 15 Pan Head Cross Recess Tapping Screws-Type C, D, F and T 16 Hexagon Head Tapping Screws-Type AB, B, BP and BT 17 Hexagon Head Tapping Screws-Type C, D, F and T 18 Hexagon Washer Head Tapping Sc
18、rews-Type AB, B, BP and BT 19 Hexagon Washer Head Tapping Screws-Type C, D, F and T 20 Technical Information 21 NUMBER: MPAPS S-D-1.101-GS/PL TITLE: Slotted and Cross Recess Tapping Screws REVISION: 1604 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without per
19、mission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2016 by Navistar, Inc. APRIL 2016 Page 3 of 21 dimensions specified in this standard. Type F is used in applications involving clogged tapped holes. Type T, in applications involving die castings. Type
20、 BT (preferred): Type BT tapping screws will have spaced threads with a blunt point and tapered entering threads, as on Type B, with one large cutting edge and chip cavity. These screws are intended for use in plastics, asbestos, and other similar compositions. 4.0 HEIGHT OF HEAD: The head height in
21、 the dimensional tables represents a metal to metal measurement. In other words, on heads having rounded top surfaces, the truncation of the rounded surface due to recess or slot is not considered part of the head height. On countersunk type heads, the height of the head is a reference dimension mea
22、sured parallel to the axis of the screw from the largest diameter of the bearing surface of the head to the point of intersection of the bearing surface of the head and basic major diameter of the screw. This point of intersection may not necessarily be the same as the actual junction of head and sh
23、ank. The height of undercut head will be covered under the heading “Short Length Screws.“ Hexagon head and hexagon washer head specifications may be found in section 31.0, 32.0, 33.0 and 34.0. 5.0 BEARING SURFACE: The bearing surface of the head will be perpendicular to the axis of the screw shank w
24、ithin 2 degrees. 6.0 DEPTH OF RECESS: The depth of recess in recessed head screws will be measured parallel to the axis of the screw from the intersection of the maximum diameter of the recess with the head surface to the bottom of the recess. Recess penetration gaging depth values are included in t
25、he dimensional tables and the method of gaging and specifications for gages are covered in MPAPS S-D- 200.101-GS/PL. Recess wobble gaging procedures and operating limits are also given in MPAPS S-D-200.101-GS/PL. 7.0 SLOT DEPTH: The depth of slot in head will be measured, parallel to axis of screw,
26、from the top of head to the intersection of bottom of slot with the head surface or bearing surface. 8.0 ECCENTRICITY: The head will not be eccentric with axis of screw by more than 3 percent of the maximum head diameter. The slot or recess in the head will not be eccentric with axis of the screw by
27、 more than 6 percent of the basic body diameter or .015 inch (for Cross Recess Head), .010 inch (for Slotted Head) whichever is greater. Eccentricity is defined as one-half of the full indicator movement (FIM) 9.0 LENGTH: The length of screw will be measured, parallel to axis of screw, from the larg
28、est diameter of the bearing surface of the head to the extreme point. Tolerance on Length Tapping Screws, Types AB and BP Nominal Screw Length Tolerance on Length Up to 1 inch, Incl. 0.03 Over 1 inch 0.05 NUMBER: MPAPS S-D-1.101-GS/PL TITLE: Slotted and Cross Recess Tapping Screws REVISION: 1604 Thi
29、s 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. 2016 by Navistar, Inc. APRIL 2016 Page 4 of 21 Tapping Screws, Types B, BT, C, D, F. and T Nominal Screw Len
30、gth Tolerance on Length Up to 3/4 inch, Incl. -0.03 Over 3/4 to 1-1/2 inch, Incl. -0.05 Over 1-1/2 inch -0.06 10.0 SPACED THREADS: (Types B, AB, BP and BT). Thread form will be as shown below. The width of flat at crest of thread will not exceed .004 inch for size 8, or smaller, and .006 inch for la
31、rger sizes. 11.0 MACHINE SCREW DIAMETER-PITCH THREADS: (Types C, D, F and T). Threads will approximate Unified Form and comply with dimensions specified herein, but will not be subject to thread gaging requirements. 12.0 LENGTH OF THREAD: (Types AB, B, BP and BT). For screws of nominal lengths equal
32、 to 8 diameters or 1-1/2 inches, whichever is shorter, the full form threads will extend close to head such that specified minor diameter limits are maintained to within one pitch (thread) of the underside of the head, or closer if practicable (see below). Screws of longer nominal lengths will, unle
33、ss otherwise specified, have a minimum length of full form thread equal to 6 diameters or 1.50 inches, whichever is shorter. (Types C, D, F, and T). Screws of nominal lengths equal to 3 diameters and shorter will have full form threads extending to within one pitch (thread) of the head, or closer if
34、 practicable (see above). For nominal lengths exceeding 3 diameters; up to and including 8 diameters or 1-1/2 inches, whichever is shorter; the full form threads will extend to within 2 pitches (threads) of the head, or closer if practicable. Screws of longer nominal length will, unless otherwise sp
35、ecified, have a minimum length of full form thread equal to 6 diameters or 1.50 inches, whichever is shorter. All dimensions are in inches. NUMBER: MPAPS S-D-1.101-GS/PL TITLE: Slotted and Cross Recess Tapping Screws REVISION: 1604 This document is restricted and may not be sent outside Navistar, In
36、c. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2016 by Navistar, Inc. APRIL 2016 Page 5 of 21 13.0 SHORT LENGTH SCREWS: Undercut Heads: Screws of nominal lengths equal to or shorter than C1, length in Table 1 and 3 will
37、have undercut heads. Reduced Tapered Point: Screws of nominal lengths equal to or shorter than the tables specified below will have the length of tapered point reduced. Tables 1 and 2 “C1“ for Types B, BF and BT and “C2“ for Type BP Table 3 “C2“ Table 4 “C“ Impractical Lengths: Screws of nominal len
38、gths less than the lengths listed in tables below for the various types are impractical. Table 1 “C1“ Table 2 “C2“ Table 3 “C3“ Table 4 “C“ FLAT AND OVAL HEADS (Types AB, B, and BP) Dimensions in inches: Table I Nominal Size C1 C2 G1 U R1 Point Length Constant* Nominal Screw Length Minimum Practical
39、 Length Head Side Height Point Taper Length Fillet Radius Type AB Type BP Type AB Other Types Type AB Type BF Other Types Max Min Min Max Max Short Point Long Point 0 3/16 1/8 7/64 13/64 3/32 .025 .018 .031 .042 .009 .070 .105 .115 1 3/16 5/32 9/64 1/4 1/8 .031 .023 .036 .048 .011 .091 .133 .145 2 3
40、/16 3/16 11/64 9 /32 5/32 .036 .028 .047 .062 .013 .119 .174 .190 3 7/32 7/32 3/16 21 /64 3/16 .042 .033 .054 .071 .015 .139 .202 .220 4 1/4 1/4 7/32 3 /8 3/16 .047 .038 .063 .083 .017 .160 .233 .254 5 1/4 1/4 1/4 25/64 3/16 .053 .043 .075 .100 .019 .179 .264 .289 6 5/16 5/16 17/64 15/32 1/4 .059 .0
41、48 .075 .100 .021 .193 .281 .306 7 3/8 3/8 5116 17 /32 1/4 .064 .053 .079 .105 .023 .211 .306 .333 8 7/16 7/16 21/64 39 /64 1/4 .070 .058 .083 .111 .025 .224 .324 .352 10 1/2 1/2 3/8 11 /16 5/16 .081 .068 .094 .125 .028 .256 .371 .402 12 9/16 9/16 13/32 25/32 3/8 .092 .078 .107 .143 .032 .296 .429 .
42、465 1/4 5/8 5/8 15/32 7/8 3/8 .107 .092 .107 .143 .038 .335 .478 .514 5/16 13/16 5/8 19/32 61 /64 7/16 .134 .116 .125 .167 .047 .418 .592 .634 3/8 - 5/8 - 1- 1 /32 7/16 .161 .140 .125 .167 .056 - .706 .747 7/16 - 3/4 - 1-15 /64 5/8 .156 .133 .150 .200 .066 - .826 .876 1/2 - 3/4 - 1- 5/16 5/8 .156 .1
43、30 .150 .200 .075 - .938 .988 * Not a controlling limitation on product. Not applicable to Type AB screws. NUMBER: MPAPS S-D-1.101-GS/PL TITLE: Slotted and Cross Recess Tapping Screws REVISION: 1604 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permissi
44、on from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2016 by Navistar, Inc. APRIL 2016 Page 6 of 21 PAN, FILLISTER, TRUSS, HEX, AND ROUND HEADS (Types AB, B, and BP) Dimensions in inches: Table 2 Nominal Screw Size C1 C2 U Point Length Constant* Nominal Screw
45、 Length Minimum Practical Length Point Taper Length Type AB Type BP Types B, BF not a controlling limitation on product. NUMBER: MPAPS S-D-1.101-GS/PL TITLE: Slotted and Cross Recess Tapping Screws REVISION: 1604 This document is restricted and may not be sent outside Navistar, Inc. or reproduced wi
46、thout permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2016 by Navistar, Inc. APRIL 2016 Page 14 of 21 28.1 Part List: 28.1.1 Approved: Nominal Size-TPI Length Type Finish Material Part Number *6 -20 1/4 AB ZN6A STL 24363R1 6-20 3/8 AB ZN6A STL 24
47、365R1 *8-18 3/8 AB ZN6A STL 24374R1 *8-18 3/8 AB PHC STL 27044R1 8-18 1/2 AB ZN6A STL 24377R1 8-18 1/2 AB PHC STL 24379R1 8-18 5/8 AB PHC STL 24615R1 8-18 3/4 AB PHC STL 27045R1 8-18 1 1/4 AB PHC STL 27047R1 *10-16 3/8 AB PHC STL 27048R1 10-16 1/2 AB ZN6A STL 24390R1 10-16 1/2 AB PHC STL 24392R1 10-
48、16 5/8 AB ZN6A STL 24394R1 10-16 3/4 AB ZN6A STL 24396R1 10-16 3/4 AB PHC STL 26304R1 10-16 7/8 AB PHC STL 27050R1 10-16 1 1/4 AB ZN6A STL 24400R1 10-16 1 1/2 AB PHC STL 27959R1 * 1/4-14 1/2 AB ZN6A STL 24407R1 * 1/4-14 1/2 AB PHC STL 26328R1 1/4-14 5/8 AB ZN6A STL 24408R1 1/4-14 5/8 AB PHC STL 2701
49、0R1 1/4-14 3/4 AB ZN6A STL 24409R1 1/4-14 3/4 AB PHC STL 26520R1 1/4-14 1 AB ZN6A STL 27378R1 Nominal Size-TPI Length Type Finish Material Part Number 1/4-14 1 1/4 AB ZN6A STL 27379R1 8-18 3/8 AB PLN SST-410 27037R1 8-18 1/2 AB PLN SST-410 27195R1 8-18 5/8 AB PLN SST-410 27038R1 8-18 3/4 AB PLN SST-410 27196R1 8-18 1 AB PLN SST-304 24385R1 8-18 1 AB PLN SST-410 27197R1 8-18 2
