Limiting tool vendors boosts efficiency

Selecting cutting tools may seem like a simple process, but without a plan it can become complex, needlessly costly and a source of machining errors. As part of an operations improvement plan in the combustion shop at Savannah Machinery Works, a startup operation, our team set two goals for selecting cutting tools: provide a system that minimizes opportunity for tool-selection and tool-usage errors and streamline the procurement process.

The first step toward error reduction was limiting toolcrib items and vendors. This was made easier because we were starting from scratch. We grouped cutting tools into categories by machining process and selected one toolmaker for each of four categories: indexable tools, solid-carbide drills, solid-carbide mills and threading tools. (We wanted different vendors for each category.)

Selection was based on the toolmakers’ experience with power generation and aerospace manufacturing and high-temperature superalloys, catalog offerings and technical support. The last item was heavily weighted as we needed to develop new machining processes.

After selecting toolmakers, we met with their application engineers and identified tools for our materials and processes. We focused only on proven tool technology and tool series that offered the largest size range.

For the indexable mills subcategory, we avoided proprietary inserts and tool bodies where possible so inserts could be sourced from other manufacturers, if needed. For indexable turning tools, we selected CNMG and CCMT 4xx series inserts so we could quickly find suitable substitutes, if needed. In both cases, we selected two insert grades: one for machining steel and one for nickel. By limiting choice, we minimized the opportunity for errors.

We met with technical representatives from the solid-carbide drill manufacturer, who helped us select tools proven for our work materials in a large range of sizes. This is because we drill a large range of diameters and depths using only one series of drill.

For solid-carbide mills, we initially chose a large toolmaker with an extensive catalog, but repeated delivery problems made us look elsewhere. We turned to a small toolmaker we were using for specials. We did not initially consider them as the main supplier because we were unaware of their full capability. We knew they had a lot of experience in aerospace and power generation, but we discovered they also stock a large number of catalog items.

Courtesy of Savannah Machinery Works