9I 92 93 94
Opal glass Low boron glass Pyrex glass Zinc base die casting alloy. do do Flint clay Plastic clay Soda feldspar Medium manganese steel.
95 96 97 98 99 Ioo I0I
BUREAU OF STANDARDS NOTES.
18-8 Chrome-nickel steel (KA2S).
45 45 45
$2 .O0 2.00 2 .OO
IOO IOO IOO 60 60 40
2.00 2.00 2.00 2.00 2.00 2.00
C, Mn, P, S, Si, Cu, Ni, Cr, V, Mo.
C, Mn, P, S, Si, Cn, Ni, Cr, V, Mo.
Complete analysis. B20~ Complete analysis. do do do do do do
Orders for any of the above samples should be accompanied by money order or check made payable to the " B u r e a u of Standards, Department of Commerce." Detailed certificates of analysis are sent to the same destination as the samples. WEAR RESISTANCE OF CARBON STEELS.
One of the major factors which causes deterioration of metals in service is wear. The cost of worn-out parts, the labor of replacement, and the time lost while repairing machinery represent a tremendous economic loss. The selection, on the basis of laboratory tests, of those metals or alloys which best resist wear is extremely difficult because of the m a n y complex factors involved. A study was recently completed of one special phase of this work, and a report will be issued in the September number of the Bureau of Standards Journal of Research. Tests of the wear-resistance of plain carbon steel were made in the Amsler machine (combined rolling and sliding friction under heavy pressures) to determine the effect of carbon content and heat t r e a t m e n t upon the wear-resistance of these particular steels. The results showed that the higher-carbon and the harder steels were more resistant to the particular type of wear studied than the lower-carbon and the softer steels.