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. 2014 by Navistar, Inc. February 2014 Page 1 of 18 NAVISTAR, INC. Material, Parts, and Process Specificati
2、ons (MPAPS) NUMBER: MPAPS F-31, Part II Former Designation: CEMS A-31 Part II TITLE: Steel Nuts CURRENT REV No.: 1402 DATE: Feb. 2014 WRITTEN/EDITED BY: Materials Engineering APPROVED BY: Materials Engineering SUPERSEDES: CEMS A-31 Pt II Oct. 2012 PRINTED COPIES OF THIS DOCUMENT MUST BE VERIFIED FOR
3、 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 practices and to determine the applicabil
4、ity of regulatory limits prior to use. Change Notice: New MPAPS format; editorial changes. 1.0 APPLICATION This specification provides guidance to the selection and use of fasteners in Navistar design. Bolted joints are used extensively in the assembly of our products and provide for adjustment, rep
5、lacement and ease of repair. Material properties of both inch and metric fasteners are covered in this specification. 2.0 SCOPE This specification covers Navistars requirements for the material and properties of steel nuts. Dimensional and general specifications for standard nuts are covered in the
6、Engineering Standard Parts (ESP) specifications, Sections E and EM. Nonstandard parts will be covered by engineering drawings which should refer to this specification for material and properties. 2.1 Restricted Chemical Substances Effective January 1, 2007, all product supplied to the requirements o
7、f this specification must comply with the requirements of the MPAPS B-50 specification. 3.0 CONTENTS PAGE REFERENCE DOCUMENTS 1 GRADE CLASSIFICATION AND NUT IDENTIFICATION 2 CHEMICAL COMPOSITION 3 MECHANICAL PROPERTIES 4 METALLLURGICAL REQUIREMENTS 8 QUALITY 15 16 METHODS OF TEST 16 SOURCE APPROVAL
8、AND QUALITY CONTROL 17 SHIPPING AND HANDLING 18 DESIGNATION ON DRAWINGS 18 4.0 REFERENCE DOCUMENTS Unless otherwise specified, the latest issue of all referenced standards shall apply. The following Specifications, Standards, and Regulations are referenced in this specification. NUMBER: MPAPS F-31 P
9、art II TITLE: Steel Nuts REVISION: 1402 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. 2014 by Navistar, Inc. February 2014 Page 2 of 18 Quality System
10、Standard ISO 9001 or TS-16949 CFR Title 29, Part 1910 SAE J995 ASMEB18.2.4.2M ASTM A563 ASTM E18 NAVISTAR Manufacturing Std. MS-D-13 ASME B18.2.2 ISO 898-2 NAVISTAR Engineering Design Std A-16 ASME B1.1 ISO 965 NAVISTAR MPAPS B-50 CEMS A-40 5.0 GRADE CLASSIFICATION AND NUT IDENTIFICATION This specif
11、ication covers inch and metric steel nut material types classified as shown in Tables I and Ia. Increasing Type and Class numbers represent increasing material tensile strengths. Requirements for marking and identification of nuts are shown in Tables I and Ia. Identification symbols may be either ra
12、ised or depressed markings. Raised markings will not project beyond the height or width of the nut. Alternate methods of marking may be used but must be approved by the purchaser. TABLE I - GRADE CLASSIFICATION AND IDENTIFICATION - INCH NUTS Designation Marking Methods Corresponding Navistar Bolt Ty
13、pe Navistar Type Obsolete IH Type Approx SAE J995 Grade Approx ASTM A 563 Grade 1 - 2 A Not Required 1 5 2 5 B - 5 8 4, 4A, 8T 8 D - 8 9 (1) - - DH(3) 9 (1) These nuts are for special use only. The same restrictions for the usage of the corresponding Navistar bolt type (per A-31 Part I) also applies
14、 to these nuts. Approval of Design Analysis and Materials Engineering is required prior to the usage of these nuts. (2) Preferred markings: non-preferred and alternate marking methods must be approved by purchaser before using. (3) Representative of Type 9 strength levels only with hex thick nut sty
15、les. DH (2) NUMBER: MPAPS F-31 Part II TITLE: Steel Nuts REVISION: 1402 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. 2014 by Navistar, Inc. February 2
16、014 Page 3 of 18 TABLE Ia. GRADE CLASSIFICATION AND IDENTIFICATION - METRIC NUTS Designation Marking Methods Corresponding Navistar Bolt Class NavistarClass Approx ISO 898-2 5 5 5.8 8 8 8.8 10* 10 10.9 12* 12 12.9 * These nuts are for special use only. The same restrictions for the usage of the corr
17、esponding Navistar bolt class (per A-31, Part I) also apply to these nuts. Approval of Design Analysis and Materials Engineering is required prior to the usage of these nuts. * Preferred markings: non-preferred and other alternate marking methods must be approved by purchaser before using. * Class 1
18、0 nut is also suitable for a Class 9.8 bolt 6.0 GENERAL REQUIREMENTS 6.1 Chemical Composition Nuts purchased to this specification will be made from steel conforming to the product analysis limits shown in Tables II and IIa. TABLE II. CHEMICAL COMPOSITION - INCH NUTS Navistar Type Element, Percent *
19、 Carbon, max Manganese, min Phosphorus, max Sulfur, max 1 0.55 - 0.12 0.35 5 0.55 0.30 0.05 * 0.15 * 8 0.55 0.30 0.04 0.05 * 9 0.55 0.45 0.04 0.05 * Alloying elements may be added, if necessary, to develop mechanical properties. * If agreed upon between purchaser and supplier, sulfur content for Typ
20、e 5 nuts may be 0.35% max and phosphorus content may be 0.12% max, provided that manganese content is 0.70% min. * If agreed between purchaser and supplier, sulfur content for Type 8 nuts may be 0.35% maximum provided that the minimum manganese content is 1.35%. * 10 8 * 12 * * * 8 10 12 NUMBER: MPA
21、PS F-31 Part II TITLE: Steel Nuts REVISION: 1402 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. 2014 by Navistar, Inc. February 2014 Page 4 of 18 TABLE
22、IIa CHEMICAL COMPOSITION - METRIC NUTS Navistar Type Element, Percent * Carbon, max Manganese, min Phosphorus, max Sulfur, max 5 * 0.58 - 0.12 0.15 8 0.58 0.25 0.06 0.15 10 0.58 0.30 0.05 0.06 12 0.58 0.45 0.05 0.06 * Alloying elements may be added, if necessary, to develop mechanical properties. *
23、Nuts of this property class may be manufactured from free-cutting steel unless otherwise agreed between the purchaser and the manufacturer. In such cases, the following maximum sulfur, phosphorus, and lead contents, respectively, are permissible: sulfur 0.34%, lead 0.35% 6.2 Mechanical Properties St
24、eel nuts purchased to this specification will have mechanical properties as shown in Tables III and IIIa. Refer to “Methods of Test,” Section 8.0. Proof load stress requirements will be determined by multiplying the appropriate proof load stress requirements shown in Tables III and IIIa by the facto
25、rs given in Table IV. The tensile stress areas are based on the stress areas of the test bolts or mandrels. For convenience, requirements converted to proof load for common sizes of hex and square nuts (proof load stress nut factor = 1.00) are shown in Tables V and Va. TABLE III MECHANICAL PROPERTIE
26、S - INCH NUTS* Designation Nominal Size, inches Proof Load Stress, minimum Hardness, HRC Navistar Type Approx SAE Grade Coarse Threaded Nuts Fine Threaded Nuts psi MPa psi MPa 1* 2 All 90000 620 80000 550 32 max 5 5 Thru 1 Over 1 thru 1-1/2 120000 105000 825 725 109000 94000 750 650 32 max 32 max 8
27、8 Thru 5/8 Over 5/8 thru 1 Over 1 thru 1-1/2 150000 1035 150000 1035 24-32 26-34 26-36 9* - 1/4 Thru 1-1/2 177000 1220 177000 1220 26-36 * See “Heat Treatment,” Section 6.4, for requirements applicable to nuts case hardened to provide resistance to wrenching damage. Tabulated proof load stresses app
28、ly to standard hex nuts per the Navistar Standard Parts book, except as otherwise noted. * Type 1 nuts are normally available only as square nuts in regular sizes and as hex nuts in machine screw sizes. * Nuts are restricted to the hex thick style per ASME B18.2.2 and the proof load stresses apply t
29、o this style nut. NUMBER: MPAPS F-31 Part II TITLE: Steel Nuts REVISION: 1402 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. 2014 by Navistar, Inc. Febr
30、uary 2014 Page 5 of 18 TABLE IIIa MECHANICAL PROPERTIES - METRIC NUTS* International Class Nominal Size, Millimeters Proof Load Stress, Minimum * Hardness, HRC MPa psi 5 Thru 7 Over 7 thru 10 Over 10 thru 16 Over 16 thru 39 580 590 610 630 84100 85 600 88500 91400 30 max 8 Thru 7 Over 7 thru 10 Over
31、 10 thru 16 810 830 840 117500 120400 122000 30 max Over 16 thru 39 920 133400 36 max 10 Thru 10 Over 10 thru 16 Over 16 thru 39 1040 1050 1060 150800 152300 153700 26-36 12* All 1220 177000 26-36 * See “Heat Treatment,” Section 6.4, for requirements applicable to nuts case hardened to provide resis
32、tance to wrenching damage. Tabulated proof load stresses apply to the standard hex nuts per Navistar Standard Parts specifications, except as otherwise noted. * Coarse threaded nuts only; fine threaded nuts are not available. * Nuts are restricted to style 2 per ASME B18.2.4.2M and the proof load st
33、ress applies to the style 2 nut. For convenience in testing, proof load stress specifications shown in Tables III and IIIa are converted to proof loads in pounds-force (lbf) and kilonewtons (kN) in Tables V and Va, respectively. Proof load requirements for different style nuts may be determined by m
34、ultiplying those in the table by the appropriate nut factor shown in Table IV. The formulas shown below Tables V and Va may be used for calculating proof loads for nonstandard size nuts. NUMBER: MPAPS F-31 Part II TITLE: Steel Nuts REVISION: 1402 This document is restricted and may not be sent outsi
35、de Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2014 by Navistar, Inc. February 2014 Page 6 of 18 TABLE IV PROOF LOAD STRESS AND PROOF LOAD NUT FACTORS - INCH NUTS Nut Style Nut Factor Hex 1.00 Slotted Hex
36、0.80 Hex Jam 0.60 Hex Thick: Coarse (b) no forging crack extends into the tapped hole beyond the first full thread; and (c) the width of any forging crack does not exceed 0.20 mm (0.008 inch) + 0.010 D. The depth of forging cracks located at the intersection of top or bottom face with the flat (thes
37、e discontinuities are sometimes interpreted as bursts) will not exceed 0.25 mm (0.020 inch) + 0.020 D (see Figure 2). 6.3.1.2.1.3 Cracks or seams located on the external surface of the locking element of prevailing nuts of the type illustrated in Figure 3 (caused by forging, seams or forming of the
38、locking element) are permitted, provided that the product meets all torque specifications that apply and the requirements of the cone proof load test described under “Inspection Procedure.” Locking element cracks located on the internal surface of prevailing torque nuts will not exceed two thread pi
39、tches in length; will not extend into the thread root; and the width of any cracks will not exceed the following: For metric-series nuts, 0.18 mm for sizes 6.0 to 11 mm, inclusive, and 0.25 mm for sizes 12 to 25 mm, inclusive. For inch-series nuts, 0.007 inch for sizes 1/4 to 7/16 inch, inclusive, a
40、nd 0.010 inch for sizes 1/2 to 1 inch, inclusive. (See Figure 3.) 6.3.1.2.1.4 Washer retainer cracks are permissible discontinuities. (See Figure 4.) 6.3.1.2.2 Seams - Seams are permissible discontinuities providing that nuts with seams, in addition to meeting the dimensional requirements detailed b
41、elow, can meet the requirements of the cone proof load test described here under “Inspection Procedure.” When specified, these nuts may also be required to be torqued on a bolt of comparable class to the proof load of the bolt. Seams will not exceed the following open width at the surface; for metri
42、c-series nuts,0.13 mm for sizes 6.0 to 11 mm, inclusive, and 0.25 mm for sizes 12 to 25 mm, inclusive. For inch-series nuts 0.005 inch for nut sizes 1/4 to 7/16 inch, inclusive, and 0.020 inch for nut sizes 1/2 to 1 inch, inclusive. (See Figure 5.) 6.3.1.2.3 Bursts - Bursts in flanged nuts will not
43、exceed a width of 0.13 mm (0.005 inch) + 0.020 F or an open depth of 0.08 mm (0.003 inch) +0.012 F, except that one burst may have a width no greater than 0.25 mm (0.010 inch) +0.040 F, or an open depth no greater than 0.15 mm (0.0065 inch) +0.024 F. (See Figure 6.) 6.3.1.2.4 Shear Failures - Shear
44、failures on flanged nuts will not exceed a width of 0.020 F or a depth of 0.030 F. (See Figure 6.) 6.3.1.2.5 Folds - Folds located at the intersection of the flange periphery and bearing surface of flanged nuts will not project below the bearing surface. (See Figure 7.) 6.3.1.2.6 Voids - Voids on th
45、e bearing surface of nuts will not exceed a depth of 0.25 mm (0.010 inch) and the combined area of all voids on the bearing surface will not exceed 5% of the specified minimum area of the bearing surface. (See Figure 8.) NUMBER: MPAPS F-31 Part II TITLE: Steel Nuts REVISION: 1402 This document is re
46、stricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2014 by Navistar, Inc. February 2014 Page 11 of 18 6.3.1.2.7 Tool Marks - Tool marks on the bearing surface will not exceed
47、a surface roughness measurement of 0.0028 mm (0.00011 inch) determined as the arithmetic average deviation from the mean surface. Tool marks on other surfaces are permissible discontinuities. (See Figure 9.) 6.3.1.2.8 Nicks and Gouges - Nicks and gouges are permissible discontinuities; however, the manufacturer will exercise due care during the manufacture and handling of nuts to minimize the number and magnitude of nicks and gouges. 6.3.1.3 Inspection Procedure 6.3.1.3.1 Unless otherwise specified
