This part of ISO 6305 specifies the quality requirements of the product and the conditions of acceptance testing for rolled non-alloy carbon steel baseplates for use with flat-bottom railway rails.
1992BS 751:1992 Specification for steel baseplates for flat bottom railway rails
BS ISO 6305-2:2007 Railway components - Technical delivery requirements - Non-alloy carbon steel baseplates has been changed from BS 751:1992 Specification for steel baseplates for flat bottom railway rails.