SPRINGS 139 



The spring end construction of tension and torsion springs should be given in 

 detail by showing all necessary views. See page 144 for typical spring ends. 



INSPECTION 



All springs received shall be carefully inspected, tested, and marked, where 

 required, for identification. 



Inspection shall cover all specification requirements noted on the spring drawings 

 and on the material specification sheets. Particular care should be exercised in 

 inspecting the material to make certain all defects noted on the material specification 

 sheets are absent. In case of doubt, one or two springs from the shipment in question 

 should be etched in a 30 per cent solution of boUing hydrochloric acid for a sufficient 

 length of time to reduce the diameter 0.002 to 0.003 in. After etching, aU material 

 or manufacturing defects are readily discernible. 



A sufficient number of springs from each shipment shall be tested to determine if 

 the spring rate is within the limits specified on the drawing. The amount of set, if 

 any, when compressed to the minimum working length must also be determined. 



All springs failing to meet the requirements referred to above shall be rejected. 

 If more than 10 per cent of the springs on any one order are rejected, the entire ship- 

 ment shall be rejected. 



Springs constructed of music wire, Monel metal, phosphor bronze, or brass shall 

 not be marked in any way for identification. Springs made of steel shaU have one or 

 two coUs at one end painted a color corresponding to that indicated as follows : Swed- 

 ish steel, blue; carbon steel, orange; chrome vanadium steel, red. The paint used 

 shall be quick-drying, oilproof, heat-resisting lacquer. 



