BUILDING MATERIALS 



163 



Screws. Flat-head screws are sold by the gross. The 

 diameter of the screw near the head is determined by num- 

 ber, which increases with the diameter and length. The 

 head is included in the length, and the number corresponds 

 to the American Screw Gauge Table. The following table 

 gives the number and length of flat-head screws carried in 

 stock, with the various numbers available for the same 

 length : 



Length of Screw 

 in Inches 



H 



Vs 



¥2 



5 A 



% 



7 A 



1 



iVa 



il4 



iH 



Available 



Numbers in 



Each Length 



o- 4 inclusive 



0-9 



1-12 



1-14 



2-16 



2-16 



4-20 



4-24 " 



4-24 " 



5-24 " 



Length of Screw- 

 in Inches 



2 



2^.:;:::::::: 



2V 2 



2^ 



3 



3 l A 



4 



4^ 



5 



6 



Available 



Numbers in 



Each Length 



5-24 inclusive 



5-24 



5-24 

 6-24 



6-26 



8-26 



8-30 

 12-30 

 12-30 

 12-30 



Equivalent of American Screw Gauge Table in Decimals of 



an Inch 



o, 

 1, 



2. 



3 



4 



,0578 

 0710 

 0842 



0973 

 1 105 



1236 

 1368 

 1500 

 1631 

 1763 



2552 

 2684 

 2816 

 2947 

 3210 



22 



24, 



26. 



28. 



30. 



3474 



3737 

 4000 



4263 



4526 



Flooring. Tamped earth or clay has proved a very satis- 

 factory flooring for some farm buildings, and cement is being 

 used more and more extensively, but wooden floors of various 

 types are and probably will for some time continue to be the 

 most common. 



House floors. In the early settlements of any part of the 

 country house floors were made of whatever material was 

 most available. White pine in 6-inch widths, dressed and 

 matched, has had very wide use. This has been replaced 

 largely within recent years by yellow pine and Washington 



