S9086-CJ-STM-010 0910-LP-105-8731 REVISION 5 NAVAL SHIPS’ TECHNICAL MANUAL CHAPTER 075 FASTENERS SUPERSEDES NSTM CHAPTER 075 REVISION 4, DATED 1 MAR 2006. DISTRIBUTION STATEMENT A: APPROVED FOR PUBLIC RELEASE; DISTRIBUTION IS UNLIMITED. PUBLISHED BY DIRECTION OF COMMANDER, NAVAL SEA SYSTEMS COMMAND. 1 MAR 2008 TITLE-1 / (TITLE-2 Blank)@@FIpgtype@@TITLE@@!FIpgtype@@ @@FIpgtype@@TITLE@@!FIpgtype@@ TITLE-2 @@FIpgtype@@BLANK@@!FIpgtype@@ S9086-CJ-STM-010 REVISION RECORD REVISION NO. DATE TITLE AND/OR BRIEF DESCRIPTION/PREPARING ACTIVITY 5 1 MAR 2008 PARAGRAPH(S) 075-2.5.1.1.3, 075-3.2.2.1, 075-3.2.3, 075-3.4.3.3, 075-3.4.3.3.2 AND 075-3.4.3.3.3 TMDERS INCORPORATED: NONE REVISION RECORD-1 / (REVISION RECORD-2 Blank) REVISION RECORD-2 @@FIpgtype@@BLANK@@!FIpgtype@@ S9086-CJ-STM-010 TABLE OF CONTENTS Chapter/Paragraph Page 075 FASTENERS ....................................... 1-1 SECTION 1 INTRODUCTION TO THREADED FASTENERS ................. 1-1 075-1.1 SCOPE ........................................... 1-1 075-1.1.1 GENERAL. .................................... 1-1 075-1.1.2 REFERENCE DOCUMENTS. .......................... 1-1 075-1.2 GENERAL ......................................... 1-2 075-1.2.1 USING FASTENERS. .............................. 1-2 075-1.2.2 FASTENER MAINTENANCE PRACTICES. ................. 1-3 075-1.2.3 HI-SHOCK. .................................... 1-3 075-1.2.4 INTRODUCTION TO FASTENER SPECIFICATIONS AND STANDARDS. ......................................... 1-4 075-1.2.4.1 Government Specifications and Standards. ............. 1-4 075-1.2.4.1.1 Federal specifications and standards. ...... 1-4 075-1.2.4.1.2 Military specifications and standards. ...... 1-4 075-1.2.4.2 Non-Government Specifications and Standards. .......... 1-5 075-1.2.5 GLOSSARY OF TERMS. ............................ 1-6 SECTION 2 IDENTIFICATION OF FASTENERS ......................... 2-1 075-2.1 GENERAL ......................................... 2-1 075-2.2 FASTENER DIMENSIONING SYSTEMS ....................... 2-1 075-2.2.1 INCH-BASED FASTENER DIMENSIONING SYSTEM. ........... 2-1 075-2.2.1.1 Background. ............................. 2-1 075-2.2.1.2 Dimensional Specifications. ..................... 2-1 075-2.2.2 U.S. METRIC-BASED FASTENER DIMENSIONING SYSTEM. ...... 2-2 075-2.2.2.1 Background. ............................. 2-2 075-2.2.2.2 Dimensional Specifications. ..................... 2-2 075-2.2.3 INTERNATIONAL METRIC-BASED FASTENER DIMENSIONING SYSTEM. .................................... 2-2 075-2.2.3.1 Background. ............................. 2-2 075-2.2.3.2 Dimensional Specifications. ..................... 2-3 075-2.3 FASTENER DESIGNATION ............................... 2-3 075-2.3.2 INCH-BASED FASTENER DIMENSIONING SYSTEM FASTENER DESIGNATION - THREAD CLASS, FIT, SERIES, AND DESIGNATION ................................ 2-3 075-2.3.2.1 Thread classes. ............................ 2-3 075-2.3.2.1.1 Class 1. ...................... 2-3 075-2.3.2.1.2 Class 2. ...................... 2-3 075-2.3.2.1.3 Class 3. ...................... 2-4 075-2.3.2.1.4 Class 5. ...................... 2-4 075-2.3.2.2 Thread fit. .............................. 2-4 i S9086-CJ-STM-010 TABLE OF CONTENTS - Continued Chapter/Paragraph Page 075-2.3.2.2.1 Class 1, 2, and 3 Fit. ............... 2-4 075-2.3.2.2.2 Class 5 Fit. .................... 2-4 075-2.3.2.3 Thread series. ............................ 2-4 075-2.3.2.3.1 UNC (Coarse Thread) Series. .......... 2-5 075-2.3.2.3.2 UNF (Fine Thread) Series. ........... 2-5 075-2.3.2.3.3 UN (Constant Pitch Thread) Series. ...... 2-5 075-2.3.2.3.4 UNJ Series. .................... 2-5 075-2.3.2.3.5 NC (National Coarse Thread) Series. ...... 2-5 075-2.3.2.4 Thread designation. ......................... 2-5 075-2.3.2.5 Thread acceptability, gauging. ................... 2-5 075-2.3.2.5.1 Fastener Fit Requirements. ........... 2-6 075-2.3.2.5.2 Significant Thread Characteristics. ....... 2-6 075-2.3.2.5.3 Thread Gauging for Repair Actions. ...... 2-6 075-2.3.2.6 Thread gauges. ............................ 2-6 075-2.3.3 U.S. AND INTERNATIONAL METRIC-BASED FASTENER DIMENSIONING SYSTEMS FASTENER DESIGNATION - THREAD CLASS, FIT, SERIES, AND DESIGNATION ................ 2-6 075-2.3.3.1 Thread classes. ............................ 2-6 075-2.3.3.2 Thread fit. .............................. 2-6 075-2.3.3.2.1 Tolerance grade. ................. 2-6 075-2.3.3.2.2 Tolerance position. ................ 2-7 075-2.3.3.2.3 Commonly used tolerance classes. ....... 2-7 075-2.3.3.2.4 Commonly used tolerance class combinations. ......................... 2-7 075-2.3.3.3 Thread series. ............................ 2-7 075-2.3.3.4 Thread designation. ......................... 2-7 075-2.3.3.5 Thread acceptability, gauging. ................... 2-8 075-2.4 IDENTIFYING REPLACEMENT FASTENERS .................... 2-8 075-2.4.2 DRAWING IDENTIFICATION REQUIREMENTS. .............. 2-9 075-2.4.3 IDENTIFYING FASTENERS ON APL’S. ................... 2-9 075-2.4.4 IDENTIFYING FASTENERS AND FASTENER STANDARD PART NUMBERS WHEN SUPPORT DOCUMENTATION IS LACKING. 2-10 075-2.5 CAPSCREWS AND INTERNAL WRENCHING BOLTS. ............... 2-12 075-2.5.1 SOCKET-HEAD CAPSCREWS. ........................ 2-12 075-2.5.1.1 Selecting Dimensional Standard .................. 2-12 075-2.5.1.1.1 Replacement Steel Socket Head Capscrews. 2-12 075-2.5.1.1.2 Replacement Cadmium-Plated Socket Head Capscrews. ................... 2-12 075-2.5.1.1.3 Replacement Black Oxide Coated Alloy Steel Socket Head Capscrews. ........... 2-14 075-2.5.1.2 NAS 1351 and NAS 1352 Part Numbers. ............. 2-14 075-2.5.1.3 Authorized Socket-Head Capscrew Substitutions. ......... 2-17 075-2.5.1.4 Socket-Head Capscrew Substitution Requiring NAVSEA Approval. ............................. 2-17 075-2.5.1.5 Identification of Socket Head Capscrews. ............. 2-17 ii S9086-CJ-STM-010 TABLE OF CONTENTS - Continued Chapter/Paragraph Page 075-2.5.2 INTERNAL WRENCHING BOLTS. ...................... 2-18 075-2.5.2.1 Distinguishing Internal Wrenching Bolts from Socket-Head Capscrews. ............................ 2-18 075-2.5.2.2 Identification Marking of Internal Wrenching Bolts. ....... 2-18 075-2.5.2.3 Restrictions on Using Internal Wrenching Bolts. ......... 2-18 075-2.5.3 HEXAGON-HEAD CAPSCREWS. ....................... 2-19 075-2.5.3.1 ASME B18.2.1 Part Numbering System. ............. 2-19 075-2.5.3.2 Zinc and Cadmium Plated Hex Head Capscrews. ......... 2-19 075-2.5.3.3 Restrictions on the Use of Grade 8, Zinc Plated Hex Head Capscrews. ............................ 2-21 075-2.6 WASHERS. ......................................... 2-21 075-2.6.1 IDENTIFYING REPLACEMENT WASHERS. ................. 2-21 075-2.6.2 COUNTERSUNK WASHERS (SINGLE SURFACE). ............. 2-24 075-2.6.3 COUNTERSUNK WASHERS (TWO SURFACES). .............. 2-25 075-2.6.4 LOCKWASHERS. ................................ 2-25 075-2.7 ZINC-PLATED STEEL NUTS AND WASHERS. .................... 2-25 075-2.8 THREAD INSERTS. .................................... 2-26 075-2.8.2 PURPOSE OF THREAD INSERT. ....................... 2-26 075-2.8.3 TYPES OF THREAD INSERTS. ........................ 2-27 075-2.8.4 HELICAL-COIL THREAD INSERTS. ..................... 2-28 075-2.8.4.1 Selection of Insert. .......................... 2-29 075-2.8.4.2 Applicable Military Standards. ................... 2-35 075-2.8.4.3 Removal of Insert. .......................... 2-35 075-2.8.4.4 Installation of Insert. ........................ 2-36 075-2.8.4.5 Removal of Insert Tang. ....................... 2-36 075-2.8.4.6 Gauging the Threads. ........................ 2-36 075-2.8.5 OVERSIZE HELICAL-COIL INSERTS. .................... 2-36 075-2.8.6 TWINSERTS. ................................... 2-36 075-2.8.7 STUD-LOCK INSERTS. ............................. 2-37 075-2.8.8 PIPE THREAD INSERTS. ............................ 2-38 075-2.8.9 THIN WALL LOCKED-IN INSERTS. ..................... 2-38 075-2.8.9.1 Thin Wall Insert Part Numbers and Materials. .......... 2-38 075-2.8.9.2 Thin Wall Insert Repair. ....................... 2-50 075-2.8.9.3 Installation of Insert. ........................ 2-50 075-2.8.9.4 Removal of Insert. .......................... 2-50 075-2.8.9.5 Oversize Thin Wall Inserts. ..................... 2-51 075-2.8.9.6 Thin Wall Insert Repair Kits. .................... 2-51 075-2.8.10 RING-LOCKED INSERTS. ........................... 2-51 075-2.8.10.1 Lock-Ring. .............................. 2-52 075-2.8.10.2 High Strength Ring-Lock Inserts. ................. 2-52 075-2.8.10.3 Repair Kits. ............................. 2-52 075-2.8.10.4 Pre-Installation. ........................... 2-52 075-2.8.10.5 Installation. .............................. 2-53 075-2.8.10.6 Removal and Replacement. ..................... 2-53 iii S9086-CJ-STM-010 TABLE OF CONTENTS - Continued Chapter/Paragraph Page 075-2.8.11 KEY-LOCKED INSERTS. ............................ 2-55 075-2.9 NONSTANDARD FASTENER APPLICATIONS .................... 2-55 075-2.9.1 LEFT-HAND THREAD APPLICATIONS. ................... 2-55 075-2.9.2 UNIFORM STRENGTH FASTENERS. ..................... 2-55 075-2.9.2.1 Bolt-Studs. .............................. 2-56 075-2.9.3 HOLES FOR UNIFORM STRENGTH FASTENERS. ............. 2-56 075-2.9.4 MULTI-JACKBOLT TENSIONER (MJBT). .................. 2-56 075-2.9.4.1 Description. ............................. 2-56 075-2.9.4.2 Benefits. ............................... 2-56 075-2.9.4.3 Tensioner Size ............................ 2-56 075-2.9.4.4 Ordering. ............................... 2-57 075-2.9.4.5 Installation and