DESIGN DATA ON PRODUCTION METHODS 



271 



STANDARD TOLERANCES FOR FORGINGS UNDER 100 LB. EACH* 



Tolerances shall be either "special" or "regular." Special tolerances are those 

 which are particularly noted in the specifications and may state any or all tolerances 

 in any way as occasion may require. Special tolerances apply only to the particular 

 dimension or thing noted. In all cases where special tolerances are not specified, 

 regular tolerances shall apply. 



Regular tolerances are divided into two divisions, "commercial standard" and 

 "close standard." Commercial standard tolerances are for general forging practice, 

 but when or where extra close work is desired involving additional expense and care 

 in the production of forgings, close standard may be specified. Close standard may be 

 specified for one or more of the following classes. When no standard is specified, 

 commercial standard shall apply. 



Classes 

 Regular tolerances are applicable to the following classes: 



1. Thickness. 



2. Width: (a) shrinkage and die wear; (b) mismatching; (c) trimmed size. 



3. Draft angle. 



4. Quantity. 



5. Fillets and corners. 



THICKNESS TOLERANCES 



(Inches) 



* Adopted by the Drop Forging Association, Feb. 11, 1937. 



