Type A is the entry level version and is made from high speed steel titanium plated. Type B is the professional version and is also high speed steel titanium plated. Key features - The thread cutting tool is designed for cleaning and lubricating after removing the bottom bracket, helping ensure proper reassembly. - Produces burr-free threads with smooth tapping, improving installation reliability. - Titanium coated steel provides rust resistance, enhancing durability and stability in use. Material and durability - Titanium coated steel offers rust-proof performance, contributing to long term durability and consistent performance. Use scenarios - Routine bottom bracket maintenance: after removing the bottom bracket, use the tool to clean and lubricate the threads, then proceed with reassembly. - Professional workshop use: Type B provides higher durability for frequent, daily maintenance tasks in a busy shop environment. - Maintenance in moist or corrosive conditions: the rust-proof titanium coating helps maintain tool integrity and reliability over time.