ITEM NAME:5pcs 16-30mm High Speed Steel Drill Set Meche Cutter for Drilling Cylindric E1W3 5pcs 16-30mm High Speed Steel Drill Set Meche Cutter for Drilling Cylindric E1W3 wear resistant, high tenacity, high hardness up to 63 - 65 HRC. Cutting blades by professional heat treatment and hot cutting, fine grinding forming perfect for cutting thin materials quickly with precision. Suitable for stainless steel, thin copper or aluminum plate, plastic sheet etc. The spring idea offers a buffering effect in the high speed drilling process to prevent too much pressure. Very suitable for use on portable electric drills, bench drills, drill presses, etc. Product Name: Bell Saws Gold color Hole Size: 16 mm / 0.62 inch, 18.5 mm / 0.72 inch, 20 mm / 0.78 inch, 25 mm / 0.98 inch, 30 mm / 1.18 inch Material: High speed steel Attention: the cut object must be well fixed, and the trepan must put perpendicular to its plan. tip: add coolant to the edge of the hole to avoid overheating and wear glasses that can protect your eyes. Package Content:1 x 16mm / 0.62inch hole saw 1 x 18.5mm / 0.72inchescious-bell 1 x 20mm / 0.78inch hole saw 1 x 25mm / 0.98inch hole saw 1 x 30mm / 1.18inch hole saw 1 x 5 black key Only the package above, the other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.