Go to wwwmcmastercom and look up hot rolled A36 steel 90 deg

Go to www.mcmaster.com and look up hot rolled A36 steel 90 degree angle (1\" times 1\" times 1/8\" wall thickness and 3 feet long). What is the cost of this material? Compare to the same size with zinc-galvanizing on the surface. How much does it cost? What does the zinc coating do for the steel? Go to www.mcmaster.com and look up the same size 90 degree angle in 6061 aluminum. What is the cost? What is the yield strength compared to the A36 steel? Using the angle bars from question 7 and 8 above, assume the cross-sectional area of the angle material is 0.23 square inches, what is the difference in weight between the A36 steel bar and the aluminum bar (over the whole 3 feet)? (show your work and assumptions) Based on the results from question 9, why or why not would you want to choose the use of aluminum or steel?

Solution

Question 7

A36 90⁰ angle (http://www.mcmaster.com/#9017k444/=148b3rz)

Cost of (1\" * 1\" * 1/8\") of 3 ft = 8.88 $

A36 90⁰ angle (Zinc Galvanic Surface) (http://www.mcmaster.com/#8968k12/=148b5jm)

Cost of (1\" * 1\" * 1/8\") of 3 ft = 11.92 $

These angles have a zinc coating for increased corrosion resistance and hence provide more durability, life and weather protection.

Question 8

AL 6061 90⁰ angle  (http://www.mcmaster.com/#8982k4/=148b0rw)

Cost of (1\" * 1\" * 1/8\") of 3 ft = 8.07 $

Yeild Strength = 35000 psi

While the Yield Strength of A36 steel was 36,000 psi.

Question 9

Assuming a cross sectional area of 0.23 sq in and length of 3ft (36 in)

Volume of the angle structure is = 0.23*36 = 8.28 cu in

Weight of Angle = 8.28 cu. in. * 0.28 lbs/cu. in. = 2.318 lbs

Weight of Angle = 8.28 cu. in. * 0.1 lbs/cu. in. = 0.828 lbs

Question 10

Steel - Good for structural members of civil or machinery application. It is hard and has higher yeild strength. But it is considerably heavy in comparision to aluminium (which has appox. same yeild strength but its a soft material). So its a trade off between strength and weight and considering the end application of the angle, material is to be chosen.

Nominal Density

of A36 steel = 0.28 lbs./cu. in.