What Are The Reasons For Easy Breakage When Drilling With Carbide Drill Bits?

   Drill breakage is an inevitable phenomenon, and to prevent its frequent occurrence, the best we can do is understand the causes of drill breakage, address the issues, and select better twist drills for drilling operations. So, what are the main reasons behind twist drill breakage?
   Hard metal drill bits require meticulous consideration of material compatibility in cutting processes. This means whether the material of the twist drill is suitable for machining the material of the workpiece. For instance, using ordinary high-speed steel grades like 6542 or 4241 to machine stainless steel materials such as 303 or 304 is essentially futile-it's like throwing eggs against a stone wall. When the drill bit material cannot overcome the workpiece material, continued drilling under impact will inevitably break the twist drill. This is one point: failure to penetrate and persistent drilling leads to easy breakage.
   The second phenomenon can be attributed to the selected material of the twist drill being unsuitable for the machining environment and material. Hard alloy is a commonly used raw material for twist drills. As is well known, alloy twist drills exhibit high hardness and wear resistance but poor toughness, making them unsuitable for hand-held drilling equipment. However, even machine drilling equipment may experience breakage. There are two main reasons: first, the workpiece material often contains impurities, some of which have high moisture content, leading to the fracture and breakage of the alloy drill bit. Second, the original hard alloy twist drill has excessively high hardness, which is incompatible with the material being processed. Another factor involves the stability of the equipment-not that urgent equipment can be used effectively with high-quality alloy twist drills, but rather maintaining stable runout and concentricity of the equipment.
   To achieve efficient drilling with carbide drill bits, selecting an appropriate one is crucial. There is no need to blindly choose the most expensive option; instead, it should be based on actual conditions. When selecting a twist drill, consider three factors: the material being processed, the equipment used, and the actual hole diameter and depth.