Popular Science Monthly 



An abrasive made by fastening sharp sand, graded according to degrees of fineness, to paper with 

 an elastic adhesive. The paper may have a grain or the fibers may be distributed generally 



ness, from No. oo to No. 3, the latter being 

 about equivalent to sandpaper No. 2. 

 Steel wool has a number of uses. It is a 

 substitute for sandpaper, especially on 

 curved surfaces, and it is useful in rubbing 

 down paint and shellac. Like sandpaper it 

 should not be used until all the work with 

 cutting tools is done. It can be manipu- 

 lated until utterly worn out. Other steel 

 abrasives are: steel emery and 

 crushed steel, and highly tern 

 pered steel. Steel emery 

 is the harder of the two 

 being nearly as hard 

 as diamond. They 

 are used in stone 

 sawing, the grind- 

 ing of glass, and 

 in lithography. 



Sandpaper 

 Sandpaper is 

 made of two spe- 

 cial kinds of pa- 

 per — cylinder and 

 Fourdrinier paper. 

 Cylinder paper has 

 a grain; that is, the 

 fibers lie in one direc- 

 tion, so that the paper 

 tears easily in that 

 direction. Fourdrinier 

 paper will not tear 

 readily in a straight 

 line, because the fibers 

 are distributed to give strength in every 

 direction. The glue used to fasten the 

 "sand" on the paper must be very elastic, 



Garnet -paper is made from natural rock 

 crushed and sifted on glue-coated paper 



and hence of a fine quality. It also serves 

 to strengthen the paper. The "sand" of 

 sandpaper is crushed flint or quartz rock, 

 and each particle of it is hard and sharp. 

 This sand is carefully sifted and graded, so 

 that sandpaper can be made in various 

 grades according to the coarseness of the 

 sand. The standards of coarseness are 

 Nos. 4-0, 3-0, 2-0, o, y 2 , 1, 1 1/2, 2, 23^, 3, 

 2> l A and 4. These grades are 

 printed on the back of each 

 sheet. The difference 

 between fine and coarse 

 may be seen in the 

 illustrations. 



Sandpaper has a 



disadvantage. 



With use, the 



corners of the 



grains of sand 



soon wear 



smooth, so that 



it does not last 



long. For this 



reason , it has been 



displaced by 



garnet-paper in 



many instances. 



Garnet-Paper 



Garnet is a natural rock, 

 (garnet ore), which is 

 largely quarried in the 

 Adirondack Mountains 

 in New York State. 

 It is crushed, sifted and measured, like the 

 sand of sandpaper. It may be mounted, 

 (glued) on a paper backing, for hand use, but 



