Imperial Long Series Twist Drill
Standards
BS 328; DIN 340; RN; ISO 494
HSS Long & Extra Long Series
These HSS straight shank, right hand cutting long series twist drills are capable of drilling up to 10x the drill diameter before the flute needs to be cleared, to avoid fouling. They are made to BS328/DIN340 RN and ISO standards, and are recommended for use with steel and cast iron.