304 



CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 



7485. 



7486. 



7487. 



7492. 



7494. 

 7495. 



No. 7485. 



No. 7486. 



No. 7487. 



No. 7492. 



AUTOMATIC DEPTH GAGE for reading directly in hundredths of a mm the depth of indenta- 

 tion of the Brinell sphere. The depth of the indentation has been shown by the United States 

 Bureau of Standards to be the correct method of comparing the hardness of metals. The 

 total scale of 150 represents an indentation of I 1 /-; mm. Complete in leather covered case. .$65.00 



MICROMETER MICROSCOPE for use with No. 7484 Hardness Tester for those who wish to 

 measure the diameter of indentation. Reads directly in mm to an accuracy of 0.001 mm. 

 Height of support, 12 inches; length of side arm, 8 inches. Complete with achromatic ob- 

 jective of 42 mm focus, ocular with stationary cross hairs, rack-and-pinion movement for 

 focusing and graduated micrometer screw for lateral motion mounted on heavy support with 

 universal adjustment 65.00 



BRINELL MAGNIFIER, hand type, for reading approximately the diameter of the indentation. 

 Consists of a magnifying lens and a small steel rule graduated in fifths of a mm. Readings 

 can be made to ^ mm 10.00 



HARDNESS TESTER, Brinell Meter, a portable instrument for determining the hardness of 

 metals by comparing the diameters of the depressions produced in the test piece and a stand- 

 ard piece of known hardness, by a sphere under the influence of the same force. The ad- 

 vantages of such an instrument over other types are its portability, unlimited range of appli- 

 cation, rugged construction and convenience in operation. Complete with one Brinell Meter, 

 12 standard 10mm balls, 6 standard bars of carefully determined Brinell hardness, 2 special 

 scales for measuring the diameter of indentation, key for opening instrument and a set of 

 direct-reading tables, with instructions for use, in leather covered carrying case, 9x6 inches; 

 total carrying weight, 6^ pounds. (Unless specified, 3 bars of hardness 170 Brinell and 3 of 



250 Brinell will be sent.) Descriptive booklet will be sent upon request 55.00 



7493. STANDARD BARS for No. 7492 each .75 



(In ordering, specify degree of hardness desired, and give serial number of instrument with 

 which they are to be used.) 



STANDARD STEEL BALLS for No. 7492, exactly 10 mm in diameter per 9ozen 1.00 



MEASURING SCALES for No. 7492, graduated to % mm, for reading to 140 mm - 



No . A B 



Beading, mm 1.5 to 3.5 3 to 5 



Each 15 .15 



