M10 x 1.25 Thread Repair Tool Kit Helicoil Wire Inserts Set 15pcs. Thread inserts material: Stainless steel. Thread tap and the drill material: HSS (High-speed Steel). Thread size: M10 x 1.25mm. The installation tools in this kit are made of high speed steel for excellent handling, while the inserts are stainless steel for increased strength and longevity.