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HANDBOOK OF MECHANICAL DESIGN 



MUSIC -WIRE SPRING STEEL SPECIFICATIONS 



Generally used for Class I compression springs in wire sizes up to and including 

 0. 105 in. wire diameter. Springs made of this wire should not be finished. 



1. Steel Manufacture 



This steel is to be of Swedish manufacture according to approved practice by 

 the acid open-hearth or electric-furnace process. 



2. Chemical Composition 



Carbon 0.60-1.00 Sulphur 0.25 max. 



Manganese 0.25-0.50 Phosphorus 0.25 max. 



Silicon . 0. 10-0.20 



3. Physical Properties 



Reduction in area, 46 per cent minimum. Elongation in 8 in., 2 per cent minimum. 



4. Surface Conditions 



Upon etching with a hot solution of hydrochloric acid sufficiently to disclose 

 surface defects, no seams, hairhne or otherwise, pits, gouges, die marks, or other 

 imperfections shall be revealed. Decarburization must be held to a minimum. 



5. Limits of Variation in Diameter 



Wire diameter 0.025 in. and under — plus or minus 0.00025 in. 

 Wire diameter 0.027 to 0.063 in. — plus or minus 0.0005 in. 

 Wire diameter 0.067 in. and over —plus or minus 0.001 in. 



6. Inspection, Rejections, and Replacements 



All springs will be rigidly inspected at the plants as received. If more than a 

 total of 10 per cent of the springs on any one purchase order are made of steel that 

 fails to comply wdth the above specifications, or with the specifications on the detail 

 drawing, the entire lot will be rejected. AU springs rejected shall be replaced by 

 the seller without further cost to the purchaser. 



