Presentation on theme: "Hardware, Fasteners, Drills, and Thread Repair"— Presentation transcript:
1 Hardware, Fasteners, Drills, and Thread Repair M.C.V.T.S.
2 Characteristics 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)
3 Fastener Grades SAE: Society of Automotive Engineers ISO: International Standards Organization
4 Fastener 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
5 Fastener 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
6 Fastener 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.
8 Bolt 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.
9 Nuts Must be matched to the bolt grade May have grade markings on the top or sidesGrade five may not be markedAre softer than bolts
10 Flat Washers Case Hardened: only hardened on the outside Through-Hardened: are hardened throughout
16 Barnhill 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
17 Assignments Chap. 6 Automotive Service Review Questions Pg 66 Chap. 6 Automotive Service WorkbookUsing the google search engine find information on SAE and ISO