– This Set Includes:> 1 X 4″(102mm) Bi-Metal Hole Saws With in 40 mm Max Cutting Depth > 1 X Mandrels, > 2 X Drill Bits, > 1 X Hex Key> 1 X Ejecting Spring – Cuttex Tools Bi-Metal Hole Saw Made of High Speed Steel (HSS) Bi-Metal, The Cutting Edge is Made of High Hardness (75~81 HRC) + %8 Cobalt, That Makes Huge Different While Working with it and Very Long Lasting Life Of Hole Saw , High Strength Hard Steel, 2 mm Thick. Very Sharp Teeth – Suitable for Metal, Steel, HardWood, PVC Panel and ALL KIND OF WOOD, Excellent Set for Commercial, Professional and Home Use. – Anti-Rust Oil on the Surface to Protect the Hole Saw From Natural Oxidation- CUTTEX TOOLS Hole Saw Set Comes With a Nice Hard Carry Case To Keep All Saw Blades and Accessories Organized and Convenient to Reuse. – Smooth finish; sharp teeth reduces resistance during cutting and allows fast and clean cuts – If you have any question about our products, please feel free to contact us. We will always provide you with professional services until you are satisfied* DESIGN & QUALITY INSPECTED BY CUTTEX TOOLS – ORANGE COUNTY – CALIFORNIA