Table 71 



STRENGTH OF MATERIALS.* 



(a) METALS. 



Name of metal. 



Aluminium wire 



Ilrass wire, liard drawn . 

 Bronze, phosphor, hard drawn 

 " silicon " " . 



Copper wire, hard drawn 

 Gold t wire .... 

 Iron, J cast .... 



" wire, hard drawn . 



" " annealed 



Lead, cast or drawn 

 Palladium t . . . . 

 Platinum t wire 

 Silver t wire .... 

 Steel, mild, hard drawn . 



" hard " " . . 



Tin, cast or drawn . 

 Zinc, cast .... 



" drawn .... 



Tensile strength in 

 pounds per sq. in. 



30000-40000 



50000-150000 

 I 1 0000- 1 40000 

 95000-1 1 5000 



60000-7 ooco 

 38000-41000 

 13000-29000 

 SOOOO-I20000 

 50000-60000 

 26000-33000 



39000 



50000 



42000 



100000-200000 



1 50000-33000 



4000-5000 



7000-13000 



22000-^0000 



(d) STONES AND BRICKS. 



Name of substance. 



Resistance to crush- 

 ing in pounds 

 per sq. in. 



Basalt 

 Brick, soft 



" hard 



" vitrified . 

 Granite . 

 Limestone 

 Marble . 

 Sandstone 

 Slate 



iSooo-27000 

 300-1 500 

 1500-5000 



9000-26000 



1 7000-26000 

 4000-9000 



9000-22000 

 4500-8000 



1 1000-30000 



(c) TIMBER. 



Name of wood. 



Tensile strength 



in pounds per 



sq. in. 



Ash . 



Beech 



Birch 



Chestnut . 



Elm . 



Hackberry 



Hickory . 



Maple 



Mulberry . 



Oak, burr . 

 " red . 

 " water 

 " white 



Poplar 



Walnut . 



Resistance to 



crushing in 



pounds per sq. in. 



1 1 000-2 1 000 

 1 1 000- 1 8000 

 1 2000-1 8000 

 I 0000-13000 

 1 2000- 1 8000 

 1 0000- 1 6000 

 15000-25000 

 8000- 1 2000 

 8000-14000 

 I 5000-20000 

 I3OOO-1S0OO 

 I 2000- 1 6000 

 20000-25000 



1 0000- 1 5000 



8000-14000 



6000-9000 

 9000-10000 

 5000-7000 

 4000-6000 

 6000-10000 



7000-12000 

 6000-SoOO 



7000-10000 

 5000-7000 

 4000-6000 

 6000-9000 

 5000-SoOO 

 4000-8000 



u ^'r^'"?''' °f f""5' materials is so variable thnt very little is gained by simple tabulation of ihe results which 

 have been obtained. A few approximate results are given for materials of common occurrence, mainlv to indicate the 

 limits between which the strength of fairly good specimens may lie. .Some tables are also given indicating the rela- 

 tion of strength to composition in the case of alloys. It has not been thought worth while to state these results 

 in other than the ordinary inch pound units. 



t On the authority of Werlheim. 



t The crushing strength of cast iron is from 5.5 to 6.5 times the tensile strength. 

 _ Notes. — According to Boys, quartz fibres have a tensile strength of between 1 16000 and 167000 pounds per square 

 inch. 



Leather belting of single thickness bears from 400 to 1600 pounds per inch of its breadth. 

 Smithsonian Tables. ^q 



