Park Tool Threaded T47 Guides for BFS-1The Threaded T47 Guides for BFS-1 from Park Tool are ideal for use as a guide when repairing (facing) damaged threads on your frame threaded bottom bracket shell. This guide is compatible with Park Tool Bottom Bracket Facing Set (BFS-1); Bottom Bracket Tapping & Facing Set (BTS-1) tools and is compatible with Drive Side (left-hand threading) bottom bracket shells.The 648L is a T47 (47mm x 1.0) left-hand threaded standard guide for use when facing bottom bracket shells with the BFS-1 Bottom Bracket Facing Set and 690-XL Oversized Facer. This guide is for use on the drive side (right side) of the bike. This side of the bike drive uses counter-clockwise or left-hand threading.NOTE: For sharpening services of cutting tools see Park Tool Sharpening Services. Always use cutting fluid such as Park Tool CF-2 when machining.Features: Ideal for facing bottom drive side (left hand threading) bracket threads Compatible Park Tool Products: Bottom Bracket Facing Set (BFS-1); Bottom Bracket Tapping & Facing Set (BTS-1)Buy Park Tool Workshop from Chain Reaction Cycles, the World's Largest Online Bike Store.