1、INTERNATIONAL TRUCK AND ENGINE CORPORATION Engineering Standard Parts NUMBER: ESP-C-28.101-GS TITLE: Hexagon Socket Head Cap Screws General Specifications (Noun Code 7450)CURRENT ISSUE DATE: August 2006 WRITTEN/REVIEWED BY: Corporate Technical Standards APPROVED BY: Corporate Technical StandardsSUPE
2、RSEDES ISSUE OF: March 2002PRINTED COPIES OF THIS DOCUMENT MUST BE VERIFIED FOR CURRENT REVISION Change Notice: Removed Cadmium (CAD) as optional finish. Zinc Dichromate (ZND) finish specification changed to Zinc Trivalent, Class 6A (ZN6A) finish specification. Added requirement to comply with CEMS
3、B-50, Restricted Chemical Substances. GENERAL: This standard conforms essentially with the American National Standard B18.3 for Hexagon Socket Head Capscrews (1960 Series). All but nominal dimensions are shown in decimal inch. HEADS: The top of screw heads will be flat, perpendicular to the axis of
4、the screw and chamfered at the periphery. The edge between the flat and chamfer may be slightly rounded. The plane of the bearing surface will be perpendicular to the axis of the screw within 1 degree. The edge between the bearing surface and the side of the head may be chamfered or rounded providin
5、g the degree of chamfer or rounding measured along the bearing face is within the tabulated limits for “S.“ The head will be at true position with respect to the axis of screw within a tolerance zone having a diameter equal to one percent of the basic screw diameter (J max) two percent total runout
6、or .006 inch, whichever is greater, regardless of feature size. Unless otherwise specified, knurling on heads will be optional with the manufacturer providing the diameter across the tops of the knurl and the diameter of the head before knurling or of the unknurled portion are within the tabulated m
7、aximum and minimum head diameter limits, respectively. The minimum head diameter will be measured on the side of the head adjacent to the chamfer or rounding at periphery of bearing face. SOCKET: Where hexagon sockets are chamfered or relieved, the depth of chamfer or relief will not exceed the equi
8、valent of 10 percent of the nominal socket size for sizes up to and including 1/16 inch and 7.5 percent for larger socket sizes. For broached sockets which are at or near the maximum limit of size, the overcut resulting from predrilling will not exceed 20 percent of the length of any flat of the soc
9、ket on sizes up to and including 1 inch, and 30 percent of the length of any flat on larger sockets. Suitability of sockets up to and including 1 inch nominal size will be checked in accordance with the functional limits for runout of head, body, and thread paragraph and the chart specified in the G
10、ages and Gaging portion of this document. Socket will be at true position with respect to the axis of screw within a tolerance zone having a diameter equal to three percent of the basic screw diameter or .005 inch, whichever is greater, for screws up to and including 1/2 inch; and of a diameter equa
11、l to 6 percent of the basic screw diameter for larger screw sizes; regardless of feature size. This document is restricted and may not be sent outside International Truck and Engine Corporation or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all
12、patent liability. 2006 International Truck and Engine Corporation. AUGUST 2006 Page 1 of 11 Copyright International Truck and Engine Corporation Provided by IHS under license with INTERNNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NUMBER: ESP-C-28.101-GS TITLE:
13、Hexagon Socket Head Capscrews - CURRENT ISSUE DATE: August 2006 General Specifications This document is restricted and may not be sent outside International Truck and Engine Corporation or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent l
14、iability. 2006 International Truck and Engine Corporation. UNDERHEAD FILLET: For all lengths of screws, the form of the fillet at junction of head and shank will be optional, providing it fairs into the bearing surface of head within the limits established by “E“ maximum plus “Q“ maximum and “E“ min
15、imum plus “Q“ minimum, and is a smooth and continuous curve having a bearing surface juncture radius of not less than “R.“ POSITION OF HEAD. BODY AND THREAD: Positional relationship of head, body and threads on screws will be such that screws will meet functional limits specified within the “Functio
16、nal Limits for Runout of Head, Body, and Thread” paragraph. BODY: The diameter of body on screws for which the body length “LB“ is applicable will be within the limits tabulated. For screws threaded full length, the diameter of the unthreaded shank under the head will not exceed the specified maximu
17、m body diameter nor be less than the minimum pitch diameter of the thread. LENGTH: The length of capscrews will be measured, parallel with the axis of screw, from the plane of the bearing surface of the head to the plane of the flat of the point. The tolerance on screw length will be as tabulated be
18、low: Nominal Size 0 thru 3/8 7/16 thru 3/4 7/8 thru 1-1/2 Over 1-1/2 Nominal Length Tolerance on Length Up to 1 inch, Incl -.03 -.03 -.05 - Over 1 inch to 2-1/2, Incl -.04 -.06 -.10 -.18 Over 2-1/2 to 6, Incl -.06 -.08 -.14 -.20 Over 6 -.12 -.12 -.20 -.24 THREADS: Unified external threads with radiu
19、s root: Class 3A, UNRC and UNRF Series for screw sizes 1 inch and smaller; and Class 2A, UNRC and UNRF Series for sizes over 1 inch, to and including 1 1/2 inches. Acceptance gaging of Class 3A threads will be on the basis of thread ring gages. LENGTH OF THREAD: On socket head capscrews, the length
20、of thread, except on short length screws, will be controlled by the grip gaging length “LG“ and the body length “LB.“ The applicable “LG“ and “LB“ dimensions for standard nominal lengths in screw sizes up to and including 1 inch are specified in Table 1. For screw sizes and lengths not covered in Ta
21、ble 1, the control on length of thread will be as described below. Grip gaging length “LG“ is maximum and will be measured, parallel to the axis of screw, from the bearing surface of the head to the face of a noncounterbored or noncountersunk standard GO thread ring gage assembled by hand as far as
22、thread will permit. It represents the minimum design grip length of the screw and will be used as the criterion for inspection and for determining thread availability when selecting screw lengths even though usable threads may extend beyond this point, on some products. Body length “LB“ is a minimum
23、 and will be measured, parallel to the axis of screw, from the bearing surface of the head to the last scratch of thread or the top of the extrusion angle. It also will be used as a criterion for inspection. The tabulated values are equal to “LG“ minus 5 times the pitch of the UNRC thread for the re
24、spective screw size. AUGUST 2006 Page 2 of 11 Copyright International Truck and Engine Corporation Provided by IHS under license with INTERNNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NUMBER: ESP-C-28.101-GS TITLE: Hexagon Socket Head Capscrews - CURRENT ISSUE
25、DATE: August 2006 General Specifications This document is restricted and may not be sent outside International Truck and Engine Corporation or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2006 International Truck and Engine
26、Corporation. For screws having nominal lengths which fall between the lengths shown in Table 1, the “LG“ and “LB“ dimensions will conform with those specified for the next shorter length for the respective screw size. For example: On a 1/4 inch size screw of 1-7/8 nominal length, “LG“ would be .50 i
27、nch and “LB“ would be .25 inch. Screws having nominal lengths which fall above heavy horizontal line in Table 1 and, in sizes 1 inch and larger, lengths which are shorter than “LT“ plus 5 times the pitch of the UNRC thread; will be threaded for full length. On these screws the complete (full form) t
28、hreads, as measured with a noncountersunk or noncounterbored standard GO ring gage, will extend to within two pitches (threads) of the bearing surface of the head for sizes up to and including 5/8 inch (see “U“ in tabulation below), and as close to the bearing face as is practicable for all larger s
29、izes. For screws having longer nominal lengths than those shown in Table 1 and for screw sizes over 1 inch, the maximum grip gaging length “LG“ and minimum body length “LB“ will be determined as follows: LG= L - LT LB= L - LTT Dimensions in inches: LT LTT U LT LTT U Thread Total Unthreaded Total Unt
30、hreaded Nominal Length Thread Length Nominal Thread Length Size Length Max Size Thread Length Length MaxCoarse Fine Coarse Fine Min Max Thread Thread Min Max Thread Thread0 .50 .62 .025 3/8 1.25 1.94 .125 .083 1 .62 .77 .031 .028 7/16 1.38 2.17 .143 .100 2 .62 .80 .036 .031 3 .62 .83 .042 .036 1/2 1
31、.50 2.38 .154 .100 4 .75 .99 .050 .042 5/8 1.75 2.82 .182 .111 3/4 2.00 3.25 - -5 .75 1.00 .050 .045 7/8 2.25 3.69 - - 6 .75 1.05 .062 .050 8 .88 1.19 .062 .056 1 2.50 4.12 - - 10 .88 1.27 .083 .062 1-1/8 2.81 4.65 - - 1-1/4 3.12 5.09 - -1/4 1.00 1.50 .100 .071 1-3/8 3.44 5.65 - - 5/16 1.12 1.71 .11
32、1 .083 1-1/2 3.75 6.08 - - The minimum thread length “LT“ and maximum total thread length “LTT“ are reference dimensions included herein for calculation purposes only. The minimum thread length “LT“ represents the distance, measured parallel to the axis of screw, from the extreme point to the last c
33、omplete (full form) thread. The maximum total thread length “LT-r“ represents the distance, parallel to the axis of screw, from the extreme point to the last scratch of thread or the top of the extrusion angle. The tabulated “LTT“ values include the minimum thread length plus a factor of 5 times the
34、 UNRC pitch, to provide for incomplete threads and a tolerance on grip length, plus an allowance which will permit the use of common tooling for more than one screw length. AUGUST 2006 Page 3 of 11 Copyright International Truck and Engine Corporation Provided by IHS under license with INTERNNot for
35、ResaleNo reproduction or networking permitted without license from IHS-,-,-NUMBER: ESP-C-28.101-GS TITLE: Hexagon Socket Head Capscrews - CURRENT ISSUE DATE: August 2006 General Specifications This document is restricted and may not be sent outside International Truck and Engine Corporation or repro
36、duced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2006 International Truck and Engine Corporation. POINTS: The end of screw will be flat or slightly concave and chamfered. The plane of the point will be approximately normal to the axi
37、s of the screw. The chamfer will extend slightly below the root of the thread and the edge formed by the flat and chamfer may be slightly rounded. The included angle of the point should be approximately 90 and will produce a length of chamfered or partial thread equivalent to .75 to 1.25 times the p
38、itch of the thread. Chamfering of points on screw sizes up to and including size 8 (.164) will be optional. SURFACE ROUGHNESS: For alloy steel, screws of sizes up to and including 5/8 inch and nominal lengths equal to or less than 8 times the basic screw diameter, the surface roughness before platin
39、g will not exceed 63 microinches (arithmetical average) on the fillet and head bearing surfaces, nor exceed 32 microinches (arithmetical average) on the threads. For larger sizes, longer lengths and corrosion resistant steel screws, the surface roughness prior to plating will not exceed 125 microinc
40、hes (arithmetical average) on the body, fillet and head bearing surfaces. Normally, it will be sufficient to ascertain that these surfaces on screws have the equivalent of a smooth machined finish by visual comparison with known surface standards. However, where it is deemed necessary and proves pra
41、ctical to measure these surfaces with commercially available equipment, roughness measurements will be taken axially on the body and fillet surfaces, and circumferentially on the bearing face. (See EDS A-12, Surface Texture.) MATERIAL: As designated by part number, socket head cap screws will be mad
42、e from steel or corrosion resistant steel conforming to the specifications below: Steel screws will be fabricated from an alloy steel having one or more of the following alloying elements; chromium, nickel, molydenum, or vanadium, in sufficient quantity to assure that the hardness range at the surfa
43、ce of Rockwell C39 to 45 for screw sizes up to and including 10 (.190) and Rockwell C37 to 45 for larger screw sizes, is met when the screws are hardened by quenching from the austenitizing temperature and tempered at a temperature of not less than 343 C (650 F). Screws will have properties conformi
44、ng to ASTM Standard A574. Corrosion resistant steel screws will be fabricated from austenitic corrosion resistant steel of types 18-8, AISI 384, or equivalent types, and will have a minimum tensile strength of 80,000 psi for sizes up to and including 5/8 inch and 70,000 psi for larger sizes. FINISHE
45、S: As designated by part number, screws will be furnished plain, plated or coated in accordance with the International Engineering Material Specification and class listed below: Zinc with Chromate (ZN6A) on steel CEMS G-20, Class 6A. Phosphate Coating (PHC) CEMS G-1, Class B2. Black Oxide (BLO) - St
46、andard with manufacturer. RESTRICTED CHEMICAL SUBSTANCES: Effective January 1, 2007, all product supplied to the requirements of this specification must comply with the requirements of the CEMS B-50 specification. WORKMANSHIP: Screws will be free from all defects which might affect their serviceabil
47、ity. AUGUST 2006 Page 4 of 11 Copyright International Truck and Engine Corporation Provided by IHS under license with INTERNNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NUMBER: ESP-C-28.101-GS TITLE: Hexagon Socket Head Capscrews - CURRENT ISSUE DATE: August 200
48、6 General Specifications This document is restricted and may not be sent outside International Truck and Engine Corporation or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2006 International Truck and Engine Corporation. PRE
49、FERRED PARTS POLICY: Preferred parts are so designated to reduce variety of parts and assure maximum availability, interchangeability and cost savings in volume buying. Material: Alloy Steel Finish: Plain (PLN), Zinc with Chromate (ZND), and Phosphate Coating (PHC) Thread: Coarse Diameters: 6, 8, 10, 1/4, 5/16, 3/8, 1/2, 5/8, 3/4, 1, 1-1/4 and 1-1/2 Lengths: All Diameters - 1/4 inch Increments thru 4 inches 1/2 inch increments - 4 thru 7 inches 1/4 and 5
