2ชิ้นส่วนมาตรฐานทั่วไป (Standard Parts) ShaftsBearings, roller or ballGear TeethThreaded Fasteners, Nuts and BoltsRivetsRibs, Spokes and LugsWashersKeys and PinsInstructor:Go through the list with your students and see if there is something missing. Springs are another item that are not normally sectioned. This would come out of their reading.
51The Nuts and bolts we all use FastenersThe Nuts and bolts we all usePHS AutoSalisbury
52SYSTEMS OF THREAD MEASUREMENT ENGLISH SYSTEMSystem of thread measurement uses a fractional system to determine thread diameter when 1/4” or larger.Each diameter increases by 1/16” up to about 1/2”Thread diameters of 1/4”, 5/16”, 3/8”, 7/16” 1/2” are most commonly used
53SYSTEMS OF THREAD MEASUREMENT TABLE OF BOLT SIZES/THREAD PITCH-UNIFIED NATIONAL COARSE (UNC) AND UNIFIED NATIONAL FINE (UNF)Size-Fractional (decimal)Threads UNCThreads (UNF)1/4" (.250")20285/16" (.3125")18243/8" (.375")167/16" (.4375")141/2" (.500")139/16" (.5625")125/8" (.625")113/4" (.750")10
54SMALL FASTENERS THREAD DIAMETERS 1/4” And Smaller use a wire size number.The smallest is Zero (0) and the largest is 14#4, #6, #8, #10 and #12 are common sizesEach has a standard UNC/UNF thread specification.Sizes are in increments of two
55HEAD SIZE Vs DIAMETER Head size of fastener is not size of fastener Size is diameter of threaded portion of fastenerFor Example Wrench size Bolt diameter 7/ /4½ /169/ /811/ /16¾ ½7/8 /1615/ /8
56BOLT LENGTH MEASURED FROM UNDER HEAD TO END OF THREADS USUALLY COME IN 1/4” INCREMENTS STARTING FROM 1/2” LENGTHLONGEST BOLTS USED IN THE AUTOMOTIVE FIELD ARE LESS THEN 6 INCHES LONG
57FASTENER STRENGTH FOR ENGLISH FASTENERS STRENGTH OR HARDNESS IS DETERMINED BY COUNTING SLASHES OR POINTS ON IT’S HEADNO POINTS UNGRADED SHOULD NOT BE USED ON AUTOMOTIVE APPLICATONS3 POINTS GRADE 5 COMMONLY USED6 POINTS GRADE 8 HIGH STRESSES
58Bolt StrengthOn U.S. bolts add 2 to the # of lines to get the grade for example 3 lines plus two equals a grade 5 Bolt
59FASTENER STRENGTH FOR METRIC FASTENERS INDICATED BY NUMBER ON HEAD (PROPERTY CLASS)4.6, 4.8, 5.8, 8.8, 9.8 AND 10.9Nuts will have a class of 4 or 6
60FASTENER STRENGTH FOR NUTS Dots are used to represent the strength of Nuts
61FASTENER STRENGTH FOR NUTS Numbers are stamped to represent the strength of Metric Nuts
63THREAD TYPE TYPE OR PITCH REFERS TO CONSTRUCTION OF THREAD NUMBER OF THREADS PER INCHNATIONAL COARSE (NC OR USS)NATIONAL FINE (NF OR SAE)ALL 1/4” AND LARGER WILL BE EITHER NC OR NF1/4” AND SMALLER USES SPECIAL DESIGNATION
64A. Pitch C. Diameter D. Thread length E. Screw length F. Threads per inch G. Head sizeHow to measure a bolt
65Coarse & Fine Thread NF NC American Standard bolts come in two thread pitch’sNC National Coarse & NF National Fine
66THREAD PITCHFrom 0-1 shows that you have 7 TPI Threads per inch. (US standard)Metric you measure the pitch, from top of thread to top of thread like # A
67Thread pitch gauge Used to find how many threads in an inch come in metric and standard
68Thread pitch gaugeThis bolt has 13 threads per inch
69Thread Designations US Threads To write out Thread designations for US bolts first you give the Diameter then the Thread Pitch then the LengthD X TPI X L½ X 13 X 2Take a bolt and give me the Thread designations for it.You can always add the grade of the bolt. Such as grade 5
70METRIC FASTENERS SIMILAR TO ENGLISH SYSTEM THREAD DIAMETER IS EXPRESSED IN MILLIMETERS (mm)THREAD TYPE IS DIFFERENTTHREAD SIZE IS DETERMINED BY MEASURING THE DISTANCE IN MILLIMETERS FROM CREST OF ONE THREAD TO CREST OF NEXT ONE.Example 1.00, 1.25, AND 1.50
71Thread Designations for Metric To write out Thread designations for Metric bolts first you give the Diameter then the Thread Pitch then the Length. Only this time it should be in millimetersD X TPI X LM12 X 1.50 X 60You can always add the Class (grade) of the bolt.
72SPECIAL FASTENERS LEFT HAND FASTENERS WILL HAVE NOTCHES CUT AT CORNERS OR WILL HAVE A “M” or a “L” STAMPED ON THEM
80Name the different clips External snap ringPal nutInternal snap ringGrease ZerkBlind RivetsWing NutE-ClipSplit or Roll Pin
81Name the clips Internal clip for a drive line (U-Joint Cross) External clip for a drive line
82THREAD REPAIROne reason why we break off bolts is that we use to long of bolts in blind holes and it jams against the bottom of the hole this bolt is then very hard to removeIf a Bolt is broken off the first thing you want to do is soak it with penetrating oil.If it is broken off flush use a hammer and punch to see if it will turn out for you.Center punch in the center of the fastener and use a left hand drill bit to try to remove it.
83THREAD REPAIRUse a screw extractor sometimes called a easy out to remove it.First drill a hole in the center, all the way through the fastener.Lightly tap the extractor with a hammer and then remove with a wrench
84THREAD REPAIR If it does not come out drill out and retap the hole. Do not break off the extractor or tap in the holeYou may also try using heat and water to heat the area around the bolt and cool the fastener.
85THREAD REPAIR Use locking pliers Reshape head or weld on nut CBC AUTOMOTIVERK
86THREAD REPAIRDrill out and use a easy outCBCAUTOMOTIVERK
87Make sure you use the right drill & tap size THREAD REPAIRHeli Coil EZ-LOKMake sure you use the right drill & tap size
88Three basic colors Blue, Red, Green Thread lockersAnaerobic cures after the components are put togetherThree basic colors Blue, Red, GreenClean and dry all parts removing dirt, oil, grease and/or any foreign material
89Blue Thread lockers Medium Strength for all bolts ¼ or larger Able to Remove with hand toolsPrevents parts from loosening from vibrationProtects threads from corrosionRecommend for valve cover bolts,rocker arm nuts, carburetor studs, motorcycle, jet skis snowmobiles etc.
90Red Thread lockers High Strength Hard to Remove Works well for studs and press fitLocks against heavy vibrationRequires extra effort to remove or special tools like heatOEM specified as 271
91Green Thread lockers Wicking Grade for Pre-assembled Parts Use on Calibration and adjustment screwsOEM specified as 290There is also a Green High Strength for sleeves
92Purple Thread lockers Low strength Use on screws up to ¼ Not used a lot in Automotive applications that I am aware of.
93Thread / Pipe SealantThread Sealant for metal tapered pipe threads and fittings replaces teflon tapeSuggested applicationsStainless steel fittings, head bolts into through holes, oil PSI sending units/sensors, oil and coolant lines, intake manifold switches, rear axle fill plug, fuel fittings
94Teflon Tape Prevents leaks Just wrap tape around threads Use on stainless, aluminum, plastic, iron, copper, or brass.
95The end for nowmost of these pictures were borrowed off of the web siteGo check it outAnd the Permatex web site a big Thank you goes to both sites