The Sealey M5 - M12 Master Thread Repair Kit is a comprehensive workshop solution designed for repairing damaged or stripped internal threads across five common metric sizes. This professional-grade kit enables mechanics, engineers and maintenance technicians to restore threads in soft metals whilst creating a stronger, more durable thread than the original. Covering thread sizes from M5 x 0.8mm through to M12 x 1.75mm, this master kit provides everything needed for thread repair applications. The stainless steel thread inserts not only repair worn or cross-threaded holes but also protect newly tapped threads against future wear and damage, making them ideal for high-stress applications in aluminium, magnesium and other soft metal components commonly found in automotive, machinery and fabrication work. The complete kit includes precision drill bits, thread taps, installation tools and lug breaking tools for professional results. With 25 inserts supplied for M5, M6, M8 and M10 sizes, pl