Presentation on theme: "Hardware, Fasteners, Drills, and Thread Repair"— Presentation transcript:
1Hardware, Fasteners, Drills, and Thread Repair M.C.V.T.S.
2Characteristics For the basic theory of threaded fasteners, see the Threaded Fastener Theory Section(http://www.srl.gatech.edu/education/ME3110/primer/ftypes.html#bolts 7/13/04)
3Fastener Grades SAE: Society of Automotive Engineers ISO: International Standards Organization
4Fastener GradesSAE Grade Capscrews: are evaluated by the American National Standards Institute (ANSI)SAE Grade Capscrews: have markings to identify their strength. (Count the lines and add two.)Example: five lines is a grade eight bolt
5Fastener GradesISO: Classifies bolt quality in terms of tensile and yield strength.ISO: Graded bolts have grading numbers on the head or cap.ISO: Grades are given as two numbers (8.9,10.9, etc)ISO:The first number is tensile strengthISO:The second number is yield strength
6Fastener GradesTensile Strength: is the maximum stress the material can withstand without breakingYield Point: is the maximum stress a material can withstand and still be able to return to its original form without damageUltimate Strength: is about 10 percent higher than the yield point. That is the point where the fastener breaks.
7Fastener Grades SAE Grade Property Class 5.8Grade 58.8Grade 79.8Grade 810.9
8Bolt StretchClamping Force: Bolts are stretched to provide a clamping forceElastic Limit: is reached when it will no longer return to its original shapeNormally bolts are stretched to 70 percent of their elastic limit.
9Nuts Must be matched to the bolt grade May have grade markings on the top or sidesGrade five may not be markedAre softer than bolts
10Flat Washers Case Hardened: only hardened on the outside Through-Hardened: are hardened throughout
16Barnhill Bolt Co., Inc. Fastener Vendor with FAQ sheet for general info. The Nutty Company, Inc. Fastener Vendor with Extensive Online Catalog (and a sense of Humor) Hayes Bolt & Supply Company Alloy Fasteners, Inc. A manufacturer, distributor, and importer of stainless steel fasteners. AROW Components and Fasteners, Inc. Fastener Vender with lots of nifty technical information on general Fasteners
17Assignments Chap. 6 Automotive Service Review Questions Pg 66 Chap. 6 Automotive Service WorkbookUsing the google search engine find information on SAE and ISO