National Geographic : 1947 Apr
© National Geographic Society Steel's Dainty Dentist Checks a Saw's 64 "Cavities" Teeth of tough steel will be inserted in these notches, as in the saw in the foreground. The cutting surfaces may be removed for sharpening or replace ment when worn. Designed to rip through big logs, this 60-inch blade is made of high-carbon alloy steel at the Disston plant in Philadelphia. Kodachromes by Willard R.Culver Coils of Tin Plate Unwind into 2-mile Ribbons Each weighs about 13,000pounds. Tin-coated plate ismachine-polished and then cut in rectangles to make cans like those held bythegirlatBethle hem Steel's Sparrows Point plant. War shortages sped development of electro plating processes, reducing theamount oftinused.