188 



treatments followed in obtaining the properties shown are outlined on the pages 

 immediately following the tables on steel. It will be noted that considerable 

 latitude is allowed in the indicated drawing temperatures and corresponding 

 wide variations in physical properties may be obtained with each heat treat- 

 ment. The properties vary also with the size of the specimens heat treated. 

 The drawing temperature is shown with the letter denoting the heat treat- 

 ment, wherever the information is available. 



Modulus of elasticity (Young's modulus). — Ratio of stress within the 

 proportional limit to the corresponding strain — as determined with an exten- 

 someter. Note. — All moduli shown are obtained from tensile tests of materials, 

 unless otherwise stated. 



Modulus of rupture. — Maximum stress in the extreme fiber of a beam 

 tested to rupture, as computed by the empirical application of the flexure for- 

 mula to stresses above the transverse proportional limit. 



Proportional limit (abbreviated P-limit). — Stress at which the deforma- 

 tion (or deflection) ceases to be proportional to the load (determined with 

 extensometer for tension, compressometer for compression, and deflectometer 

 for transverse tests). 



Shore scleroscope hardness. — Height of rebound of diamond-pointed 

 hammer falling by its own weight on the object. The hardness is measured on 

 an empirical scale on which the average hardness of martensitic high carbon 

 steel equals 100. On very soft metals a "magnifier" hammer is used in place 

 of the commonly used "universal" hammer and values may be converted to 

 the corresponding "universal" value by multiplying the reading by 4/7. The 

 scleroscope hardness, when accurately determined, is an index of the tensile 

 elastic limit of the metal tested. 



Ultimate strength in tension or compression. — Maximum stress de- 

 veloped in the material during test. 



Yield point. — Stress at which marked increase in deformation (or deflec- 

 tion) of specimen occurs without increase in load (determined usually by 

 drop of beam or with dividers for tension, compression, or transverse tests). 



TABLE 184.— INDUSTRIAL WOVEN-WIRE SCREENS* 



Industrial wire cloth may be specified in any malleable metal, the physical characteristics of 

 which will permit of its being commercially drawn into wire and woven into cloth. This indus- 

 trial wire screen is manufactured with openings from about 15 inches to a very fine wire cloth 

 with openings of .0017 inch, using for larger screens rods 2 inches in diameter and for the 

 smaller-opening cloth, wire .0014 inch in diameter. 



Industrial wire cloth specification, market grade 



Mesh 

 per 



lineal 

 inch 



1X1. 

 2X2. 

 3X3. 

 4X4. 

 5X5. 

 6X6. 

 8X8. 



Wire 



diameter 



inch 



. .080 

 . .063 

 . .054 

 . .047 

 . .041 

 . .035 

 . .028 



10 X 10 025 



12 X 12 023 



14 X 14 020 



16 X 16 018 



18 X 18 017 



20X20 016 



24X24 014 



Open- 

 ing 

 inch 



.920 



.437 



.279 



.203 



.159 



.132 



.097 



.075 



.060 



.051 



.0445 



.0386 



.0340 



.0277 



Percent 

 open 

 area 



84.6 

 76.4 

 70.1 

 65.9 

 63.2 

 62.7 

 60.2 

 56.3 

 51.8 

 51.0 

 50.7 

 48.3 

 46.2 

 44.2 



Mesh 

 per 



lineal 

 inch 



Wire 



diameter 



inch 



30X30 013 



35X35 011 



40X40 010 



50X50 009 



60X60 0075 



80X80 0055 



100 X 100 0045 



120 X 120 0037 



150 X 150 0026 



180 X 180 0023 



200X200 0021 



250X250 0016 



270X270 0016 



325X325 0014 



Open- 

 ing 

 inch 



.0203 

 .0176 

 .0150 

 .0110 

 .0092 

 .0070 

 .0055 

 .0046 

 .0041 

 .0033 

 .0029 

 .0024 

 .0021 

 .0017 



Percent 

 open 

 area 



37.1 

 37.9 

 36.0 

 30.3 

 30.5 

 31.4 

 30.3 

 30.7 

 37.4 

 34.7 

 33.6 

 36.0 

 32.2 

 30.0 



* Data furnished by the W. S. Tyler Co., Cleveland. 

 SMITHSONIAN PHYSICAL TABLES 



