Specification Brand : HARFINGTON BulletPoint1 : Size - Grits: 200-230 Grits; Diameter: 4mm / 0.16"; Head Length: 7mm / 0.28"; Shank Diameter: 2.35mm / 3/32"; Shank Length: 38mm / 1.5"; Total Length: 45mm / 1.8"; The multi-purpose tool diamond drill bit set is packaged in a sturdy plastic box for your convenience to carry and store BulletPoint2 : Material - This grinding bit is made of stainless steel, which has excellent heat and corrosion resistance, and is covered with a sharply titanium plated diamond particle coating that will not fall off or deform due to repeated use BulletPoint3 : Features - The round handle design of the rotary tool diamond grinding drill bit makes it suitable for most electronic grinders, engraving machines, hanging grinders and hand drills, which is very suitable for gemstone carving, molding repair, casting cleaning, rust removal and polishing, and DIY enthusiasts BulletPoint4 : Applications - The diamond drill bit set is very suitable for home decoration and handicrafts. It is a good helper for polishing, grinding, drilling, cutting, engraving and other operations, which can be engraved on various materials, such as tiles, ceramics, marble, stone, ceramics, agate, and even hard metals such as iron and silver BulletPoint5 : Wide Use - The grinding bit is also suitable for grinding and polishing nails, which can meet all needs of removing dead skin, shaping or removing gel art nails, which is suitable for natural nails and artificial nails, suitable for nail art beginners and professionals GpsrSafetyAttestation : 1 ItemName : HARFINGTON 20pcs 200-230 Grits Diamond Grinding Bit 4mm Bullet-Head 2.35mm Shank 7mm Length Titanium Plated Stone Sanding Drill Bits Rotary Tool for Nails Grinding Polishing ItemPackageDimensions_Height : 0.59 inches ItemPackageDimensions_Length : 5.91 inches ItemPackageDimensions_Width : 5.91 inches ItemTypeKeyword : cutting-burrs Manufacturer : HARFINGTON NumberOfItems : 1 PartNumber : htf241218hh000357 ProductDescription : This grinding bit is made of stainless steel, which has excellent heat and corrosion resistance, and is covered with a sharply titanium plated diamond particle coating that will not fall off or deform due to repeated use The round handle design of the rotary tool diamond grinding drill bit makes it suitable for most electronic grinders, engraving machines, hanging grinders and hand drills, which is very suitable for gemstone carving, molding repair, casting cleaning, rust removal and polishing, and DIY enthusiasts The multi-purpose tool diamond drill bit set is packaged in a sturdy plastic box for your convenience to carry and store The diamond drill bit set is very suitable for home decoration and handicrafts. It is a good helper for polishing, grinding, drilling, cutting, engraving and other operations, which can be engraved on various materials, such as tiles, ceramics, marble, stone, ceramics, agate, and even hard metals such as iron and silver Wear appropriate protective equipment when using to protect your eyes ; keep the workpiece and the grinding head stable during use to avoid excessive vibration and force; the operating speed is kept between 30000~50000RPM. Exceeding the maximum speed may cause the drill bit to jump, reduce the grinding effect, and even cause the rod to bend in severe cases