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Aviation History
1918
1918 - 0265.PDF
MARCH 7, 1918. following tolerances shall be allowed on wall thickness andontside diameter : TOLERANCES •*".--•. Outside'"•'•'- diameter. ~ Inches. 0-0.50,0.51- .75 .76-1.00 - •; '•••• 1.01-1.25,--, - 1.26-1.50 ,.r.r 1.51-1.751.76-2.00 ;•,;£ 2.01 : Millimetres.- ' 0-12.70 13.J1 -19.0519.06 -25.40 25.41 -31-80•-; 3I.8I -38.10 38.II -44.4544.46 -50.80 50.81 FOR OUTSIDE DIAMETER AND WALL THICKNESSES. Toleranceson outside diameter.Inch. ± .002± .0025 ± .003± -0035 ± .004± .0045 ± .005± (-25%) Millimetre.±0.05 ± .06.08 .09.10 .11.13 Wall thickness.Inch. ±± ±± ± ± (-25%) 0.0157- .0312.0313- .0625 .0626— .1250 .1251- .2500 .2501- .3125 .3126- .3750 Millimetres.0-0.397 0.40 - .790.791 -1.59 1.591 -3.173.171 -6.35 6.351 -7-947.941 -9-53 Wall-thickness tolerance. Inch. ±0.001 ± .002 * 003 ± .005 ± .008 ± ,0125 ± .0150 Millimetre. ±0.03 ± .05 ± .08 • ± .13 , ± .20 ± .32± .38 (b) Length.—When no length is specified, tubes may be shipped in stock lengths of 10 ft. (3 .04 m.) to 14 ft. (4.27 m.>. When ordered in definite lengths no length shall be less than that specified. 3iVi6—Specifications for Aluminium Alloy Sheet, i GENERAL.—1. The general specifications, 1G1, shall form, according to their applicability, a part of these specifications. MATERIAL.—2. The aluminium alloy of these sheets shall be made from standard No. 1 aluminium conforming to I.A.S.B. specification 2N1. The specific gravity of the alu- minium alloy shall not be greater than 2.85. MANUFACTURE.—3. No scrap shall be used other than that produced in the manufacturer's own plants and which is of the same composition as the material specified. WORKMANSHIP AND FINISH.—4. (a) All sheets shall besound, flat, free from buckles, seams, discoloration or other -surface defects. *) Any sheet may be rejected because of injurious de- fects or faults in manufacture at any time, notwithstanding .that it has previously passed inspection ; it shall be returned to the manufacturer at the latter's expense. This clause shall not be taken to apply to materials fabricated after export. PHYSICAL PROPERTIES AND TESTS.—5. The sheets may be Specified in either of two tempers as desired. Specimens cut in any direction from the sheets must have the following physical properties : Tensile Test.—(a) Temper i— Kilo- grams Pounds per square milli- metre 38.6 17.5 per squareinch 55,ooo25,000 15 per cent." Temper 2 Kilo-grams Pounds perper square square milli-inch metre 50,000 35.125,000 17.5 20 per cent. Minimum tensile strength ....Minimum yield point Minimum elongation in 2 inches Bend Test.—(b) Strips cut from sheets of either temper shall withstand being bent cold through an angle of 180 deg. around a diameter equal to four times the thickness ot the sheet. SELECTION OF TEST SPECIMENS.-—6. Test specimens shall be cut from a sheet selected from each 500 pounds or individual lot submitted of less than 500 pounds. DIMENSIONS AND TOLERANCES.—7. The tolerances upon sheets shall be those given in the table below : Brown &Sharpe gauge Tolerance 10-1718-36 Inch±0.003 ± .002 Thick- ness Millimetres 2.588-1.151 1.024- -4°4 Toler- ance M illimetre 0.070 .051 Thick-ness Inch 0.1019-0.0453 .0403-.0159 —_, .,_T .„_,. DELIVERY, SHIPPING AND PACKING.—8. The sheets shallbe delivered in boxes of gross weight not greater than 220 lbs. (100 kg.). 3S29—Specifications for annealed Carbon Steel Forgings and Stampings. ..;•'• (65,000 lbs. per sq. in. tensile strength.) , ;.,n 3 GENERAL.—1. The general specifications, 1G1, shall form, according to their applicability, a part of these specifications. MATERIAL.—2. The steel from which these forgings or stampings are made shall conform to I.A.S.B. specification 3S2 ; the steel has the following comparison : 5TCH1 P* t**>mim Number 1035 Carbon 0.30-0.40 Man- ganese 0.50-0.80 Phos-phorus maxi-mum 0.045 Sulphurmaxi- mum 0.050 MANUFACTURE.—3. Heat Treatment.— a) All forgings'orstampings shall be annealed. > « (b) Forgings or stampings which fail to meet the physical tests may, at the option of the purchaser, be reannealed. WORKMANSHIP AND FINISH.—4. (a) JThe forgings and stampings must be uniform in quality, free from pipes, laps, cracks, twists, seams, and must have a workmanlike finish. (0) A forging or stamping may be rejected at any time because of injurious defects or faults which are revealed by manufacturing operations, notwithstanding that it has previously passed inspection. Such rejected forgings or stampings shall be returned to the manufacturer at his expense. This clause shall not apply to materials fabricated after export. PHYSICAL PROPERTIES AND TESTS.—5. (a) The heat- treated forgings or stampings shall have the following physi- cal properties : ... ' Tensile Test.—(b) '•"'.' . . • Kilogramsper squaremilli- metre 45-7 '25.3 '•-••- Pounds . per , . square ' inch Minimum tensile strength.. .. .. .. .. 65,000 Minimum yield point . . . . . . . . . . 36,000Minimum elongation in 2 inches or proportional gauge length .. .. •„ .. .. .. .. 25 per cent.Minimum reduction of area' .. .. .. .. 50 per cent. Impact Test.—(c) When impact-testing machines of the pendulum type are available, tests shall be carried out if required to determine the specific impact work of rupture in foot-pounds (or kilogrammetres). Results markedly lower than the average for this type of material will be sufficient cause for further investigation (or reheat treatment) of the material. Brinell Hardness Test.—(d) The Brinell hardness test shall be made after the tensile test has been met. The procedure shall be as follows : (1) Forgings for a Prolongation for Tensile Test Speci- mens : A hardness test shall be made on the prolong and on the opposite end of the forging. The hardness values obtained must agree within 3 per cent. Hardness values of other forgings in the same lot must agree with the average of the two test values within 3 per cent. (2) Forgings or Stampings Without Prolongations : Hard- ness tests shall be made on the forgings or stampings selected for the tensile test and must agree within 3 per cent. The hardness values of other forgings or stampings in the same lot must agree with the average of the values so obtained within 3 per cent. (3) Forgings or Stampings from which a Tensile Test Specimen can not be Procured : A hardness test shall be made on the forged bar representing the forgings or stampings. The hardness values of the forgings or stampings in the lot must agree with that obtained on the bar within 3 per cent. SELECTION OF TEST SPECIMENS.—6. (a) Forgings or Stampings weighing 6 lbs. 3.7 kg.) or over.—If desired, each piece may be required to have a prolongation for the tensile test. Two per cent, of the forgings or stampings in each lot shall be sub- jected to the tensile test unless a tensile test is specified for each forging or stamping. (b) Forgings or Stampings weighing less than 6 lbs. (3.7 kg.) and of suitable section for securing a Tensile Test Specimen.-^- Two per cent, of the forgings or stampings shall be taken for the tensile test. (c) Forgings or stampings from which no tensile test specimen can be secured shall be represented by a bar forged from the same material, and to the ruling section of the for- gings or stampings in the lot. The bar must be heat-treated with the lot which it represents. (d) At least one tensile test shall "be made for each lot of 50 forgings or stampings. (e) A hardness test may be required on each forging or stamping offered. At last 25 per cent, of thiH- pieces in each lot shall be tested for hardness. (/) All the forgings or stampings in a lot shall be heat treated at the same time, and if possible shall be from the same heat of steel. DIMENSIONS AND TOLERANCES.—7. The forgings and stamp- ings shall conform to the dimensions on the drawings within the tolerances specified. Surfaces which are to be machined shall admit of finishing to the required dimensions ^without leaving trace of the original surface. PACKING, SHIPPING, AND DELIVERY.—8. Small forgings or stampings shall be boxed for shipment; the gross weight of individual boxes must not exceed 220 lbs. 100 kg.). Each kind and lot of forgings or stampings shall be kept separate as inspected. 26t
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