Radiographic examination of fusion welded butt joints in steel.  methods for steel 2 mm up to and including 50 mm thick /  Part 1: 
British Standards Institution 
 - 11 leaves :  illustrations ;  30 cm. 
 - British standard ;  BS 2600 : Part 1 : 1983 .
 - British standard ;  BS 2600 : Part 1 : 1983 .