Regulus of antimony Well fluxed with borax and rosin in mixing. Bearing Metal (Pennsylvania Railroad): Copper BEARING METAL In the Journal of the Franklin Institute G. H. Clamer states that 13 parts antimony and 87 parts lead make an excellent bearing metal, these being exactly the proportions which give a homogeneous For heavier duty tin should be added. structure. ALUMINUM CAN be melted in ordinary plumbago crucibles the same as brass and will not absorb silicon or carbon to injure it unless overheated. Melts at 1157 degrees Fahr. or 625 Cent. Becomes granular and easily broken at about 1000 Fahr. Shrinkage of pure aluminum . Nickel Aluminum Casting Alloy Special Casting Alloy .2031" per foot .1875" .1718" 20,000 pounds to The most used alloys have a strength of about square inch at a weight of one third that of brass. Iron or sand molds can be used and should be poured as cool as it will run to avoid blowholes. Burnishing. — Use a bloodstone or steel burnisher, with mixture of melted vaseline and kerosene oil or two tablespoonfuls of ground borax, dissolved in a quart of hot water and a few drops of ammonia added. Frosting. Clean with benzine. Dip in strong solution of caustic soda or potash, then in solution of undiluted nitric acid. Wash thoroughly in water and dry in hot sawdust. Polishing. Any good metal polish that will not scratch will clean aluminum. One that is recommended is made of Stearic Acid One Part Grind fine and mix very well. Castings are cleaned with a brass scratch brush, run at a high speed. Sand blasting is also used both alone and before scratch brushing. Spinning. A high speed, about 4000 feet per minute, is best for spinning. This means that for work 5 to 8 inches in diameter, 2800 to 2600 revolutions per minute is good, while for smaller work of 4 inches this would go up to 3200 г.p.m. Turning. Use a tool with shearing edge similar to a woodcutting tool as they clear themselves better. Use kerosene or water as a lubricant, or if a bright cut is wanted use benzine. For drawing on a press use vaseline. 7.481 gallons. = .134 cu. ft. One cubic foot weighs 62.425 lbs. at 39.2 deg. Fahr. One gallon weighs 8.345 lbs. 2016 gi. For rough calculations 1 cu. ft. is called 7 gallons and 1 gallon as 8 lbs. 60 seconds 60 minutes I circle ANGLES OR ARCS = 1 minute. 90 degrees = 1 rt. angle or quadrant = I degree. 360 degrees = I circle. 360° = 21,600' I, 296,000". I minute of arc on the earth's surface is 1 nautical mile times a land mile or 6080 feet. |