Features: <br>Drill bit is made from carbon steel and countersink is made from good quality 45# steel which ensures a long service life. <br>Combined drill bit and countersink bit is great for drilling, chamfering, deburring and countersinking. <br>There are 10 sizes of 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 7mm, 8mm, 10mm and you can choose the one you need. <br> <br>Five flutes design provides small chip loads and quicker removal, it can discharge wood sawdust more rapidly and smoothly. <br>Suitable for drilling holes on board of low hardness such as wood, plastic and other soft material. <br> <br> <br> <br>Specifications: <br>Material: Carbon steel(drill bit), 45# steel(countersink) <br>Countersink Flute: 5 <br> <br>Drill Bit Diameter: 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 7mm, 8mm, 10mm, 3-10mm(3/4/5/6/7/8/10mm), 3-6mm(3/4/5/6mm)(Optional) <br>Countersink Diameter: 15.8mm <br>Hex Key Size: 55 x 20mm <br>Quantity: Your choice <br> <br> <br>Package Includes: <br>1pc(or 1 set) x Countersink Drill Bit <br>1 x Hex Key <br> <br> <br>Note: There are only 7pcs in 3-10set, and only 4pcs in 3-6set.<br>1、Drill bit is made from carbon steel and countersink is made from good quality 45# steel which ensures a long service life <br>2、Combined drill bit and countersink bit is great for drilling, chamfering, deburring and countersinking <br>3、There are 10 sizes of 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 7mm, 8mm, 10mm and you can choose the one you need <br>4、Five flutes design provides small chip loads and quicker removal, it can discharge wood sawdust more rapidly and smoothly <br>5、Suitable for drilling holes on board of low hardness such as wood, plastic and other soft material