Hole making is a common operation

        Hole making is a common operation in any machine shop, but choosing the best type of cutting tool for each job is not always obvious. It’s best to have a drill that’s right for the material of the workpiece, delivering the desired performance, and giving you the most profit from the job you’re doing.
       Fortunately, considering the four criteria when choosing carbide and indexable drills can simplify the process.
        If the answer lies in long, repetitive processes, invest in an indexable drill. Commonly known as spade drills or replacement bits, these bits are designed to allow machine operators to quickly replace worn cutting edges.
        This reduces the overall hole cost in high volume production. Compared to the cost of a new solid carbide tool, the initial investment in the drill body (socket) quickly pays off through reduced cycle times and insert replacement costs. In short, fast changeover times combined with lower long-term cost of ownership make indexable drills the best choice for high-volume production operations.
        If your next project is a short run or custom prototype, solid carbide drills are the best choice because of the lower initial cost. Because tool wear is less likely to occur when machining smaller workpieces, ease of cutting edge change is not critical.
        In the short term, indexable cutters may have a higher initial cost than solid carbide drills and therefore may not pay off. Lead times for carbide tools can also be longer depending on where these products are sourced. With solid carbide drills, you can maintain efficiency and save money on a variety of holes.
        Note the dimensional stability of regrinding carbide tools compared to replacing worn cutting edges with new inserts. Unfortunately, with a resharpened tool, the diameter and length of the tool no longer match the original version, it has a smaller diameter and a shorter overall length.
        Reground tools are more commonly used as roughing tools and require new solid carbide tools to achieve the required final size. When using reground tools, another step is added to the manufacturing process, allowing the use of tools that no longer fit the final dimensions, increasing the cost of the hole in each part.
        Machine operators know that a solid carbide drill can operate at higher feed rates than an indexable tool of the same diameter. Carbide cutting tools are stronger and harder because they do not fail over time.
        The machinists decided to use uncoated solid carbide drills to reduce regrinding time and reorder time. Unfortunately, the lack of coating reduces the excellent speed and feed characteristics of carbide cutting tools. At the moment, the performance difference between solid carbide drills and indexable insert drills is almost negligible.
       The size of the job, the initial cost of the tool, the downtime for replacement, regrinding and triggering, and the number of steps in the application process are all variables in the cost of ownership equation.
        Solid carbide drills are a smart choice for small production runs due to their lower initial cost. As a rule, for small jobs, the tool does not wear out until it is completed, which means no downtime for replacement, regrinding and start-up.
        Indexable drills can provide a low total cost of ownership (TCO) over the life of the tool, enabling long-term contracts and high-volume operations. The savings start when the cutting edge wears out or breaks because only the insert (also known as insert) can be ordered instead of the entire tool.
        Another variable to reduce costs is the amount of machine time saved or expended when changing cutting tools. Changing the cutting edge does not affect the diameter and length of the indexable drill, but since the solid carbide drill must be reground after wear, it should be touched when changing the carbide tool. This is the time when parts are not produced.
        The final variable in the cost of ownership equation is the number of steps in the hole making process. Indexable drills can often be brought to specification in one operation. In many cases, when solid carbide drills are used, finishing operations are added after regrinding the tool to match the requirements of the job, creating unnecessary steps that increase the cost of machining the manufactured parts.
        In general, most machine shops require a wide variety of drill types. Many industrial tool suppliers offer expert advice to help you select the best drill for a particular job, while tool manufacturers have free cost-per-hole resources to help guide your decision making.