Saw Hole Saw for Core Drill Bit diam】Diameter 55mm The core drill bit is made of carbide alloy steel, the blade is extremely sharp and resistant to cutting. 【Bimetal Hole Saws】A twist drill bit inside faster, which is removable and replaced. 【Safe collar】With built-in safety collar to prevent over-drilling. 【Use for】Can be clamped on hand drill and bench drill for thick steel plate, cast iron, stainless steel, non-standard angle iron and other metal open holes. Carbide Hole Saw Made of high quality hard alloy, durable. Precision-ground tungsten carbide teeth for long life and fast cutting. Each edge is part of the cutting work characteristics, making the hole not easy to produce the phenomenon of collapse. Fine Grinding Center Drill The hole saw has a twist drill inside, which is removable and replaceable. Smooth cutting ensures accurate drilling. Carbide Teeth and Core Hole Carbide teeth for quickly cutting round and clean holes. The core hole makes it easy to remove debris from the