1. A 20-mm power screw for a hand-cranked arbor press is to have a single-start square thread with a pitch of 4 mm. The screw is to be subjected to an axial load of 5 kN. The coefficient of friction for both threads and collar is estimated to be about 0.09. The mean friction diameter … Read more
1.You have been assigned the task of examining a number of large flood gates installed in 1931 for irrigation control at a remote site on the Indus River in Pakistan. Several large steel bolts appear to have developed cracks, and you have decided that they should be replaced to avert a potentially serious failure of … Read more
1.A high-speed “closing machine” is used in a tomato canning factory to install lids and seal the cans. It is in the middle of the “pack” season and a special bracket has separated from the main frame of the closing machine because the -24 UNF-2A hex-head cap screws used to hold the bracket in place … Read more
1.A standard coarse-thread metric cap screw made of steel has a major diameter of 10.0 mm. If a torque wrench is used to tighten the cap screw to a torque of 35 N-m, estimate the axial preload force induced in the cap screw. It may be assumed that the coefficient of friction is about 0.15 … Read more
1.A -20 UNF-2A SAE Grade 2 steel cap screw is being considered for use in attaching a cylinder head to an engine block made of 356.0 cast aluminum . It is being proposed to engage the cap screw into an internally threaded hole tapped directly into the aluminum block. Estimate the required length of thread … Read more
1. You are asked, as a consultant, to determine a procedure for finding a “best estimate” for the design stress to be used in designing the helical-coil springs for a new off-the-road vehicle. The only known information is: ( 1. ) The spring material is a ductile high-strength ferrous alloy with known ultimate strength, , … Read more
1. A proposed helical-coil compression spring is to be wound from standard unpeened music wire of 0.038-inch diameter, into a spring with outer coil diameter of inch and12 total turns from end-of-wire to end-of-wire. The ends are to be closed. Do the following: a. Estimate torsional yield strength of the music wire. b. Determine the … Read more
1.A helical-coil compression spring is to be designed for a special application in which the spring is to be initially assembled in the mechanism with a preload of 10 N, and exert a force of 50 N when it is compressed an additional 140 mm. Tentatively, it has been decided to use music wire, to … Read more
1. Two steel, helical-coil compression springs are to be nested around a common axial centerline. The outer spring is to have an inside diameter of 38 mm, a standard wire diameter of 2.8 mm, and 10 active coils. The inner spring is to have an outside diameter of 32 mm, a standard wire diameter of … Read more
1.A round wire helical-coil tension spring has end loops of the type shown in Figures 14.7(a) and (b). The wire diameter of the spring is 0.042 inch, and the mean coil radius is 0.28 inch. Pertinent end-loop dimensions are riA 0.25 inch and riB 0.094 inch. An applied axial static tension force of F 5.0 … Read more