[Code of Federal Regulations] [Title 49, Volume 4] [Revised as of October 1, 2005] From the U.S. Government Printing Office via GPO Access [CITE: 49CFR231.20] [Page 507] TITLE 49--TRANSPORTATION CHAPTER II--FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PART 231_RAILROAD SAFETY APPLIANCE STANDARDS--Table of Contents Sec. 231.20 Variation in size permitted. To provide for the usual inaccuracies of manufacturing and for wear, where sizes of metal are specified, a total variation of 5 percent below size given is permitted.