Use Only The Carbide Needed

Shops of all stripes are under the gun to make more with less. Price pressures from customers, delivery pressure and competition from all sides make production a continuous challenge.

Increasing efficiency and internal cost control are about the only levers a shop has at its disposal to stay ahead and stay in business. In cutting tools for example, many precision machined parts makers have embraced carbide cutting tools because of their higher speed production capabilities and virtually infinite geometry variations. In the past couple of years though, carbide has come under pressure from increased demand for the material.

Specifically, the cost of APT, a key ingredient in tungsten carbide cutting tools, has skyrocketed. Demand from Asia and other emerging metalcutting markets has pressured available supplies of APT and other raw materials, resulting in higher tooling costs.

In response to this situation and quick-change demands from its customers, Ingersoll Cutting Tools offers a modular line of solid carbide cutting tips that attach to reusable tool shanks. The idea is to help conserve the amount of carbide needed to machine parts by exchanging only the cutting tip of the rotating tool. The company calls the line Chip-Surfer.

This system is engineered for use on today’s modern machining centers and is well suited to Swiss-type machines and turning centers with live-tooling capability. The shank and tool tip are rated at a maximum of 30,000 rpm. They are designed for ballnose, chamfer, spotting, countersinking, corner breaking, drill milling, plunging and T-slotting operations, and they are currently available in end mill sizes between 0.312 and 0.750 inches in diameter.

Standard geometries are pressed and ground. Custom requirements are ground from stocked blanks to expedite delivery. Submicron carbide grades are specified for these tool tips and most are designed using high positive rake angles with a 45-degree helix for free cutting. Based on diameter, end mill tips are stocked with 2, 3, 4, 6, 8 and 10 flute options with various corner configurations.

In operation the shop uses a steel, heavy metal or carbide shank sized for an ER11 or ER16 collet. Because of the free-cutting geometry of the tool tips, new shanks were engineered and stocked with necked-down diameters to allow larger diameter tools in smaller diameter collets without a loss of torque. Shanks are modular and come in various lengths for optimum rigidity in long-reach applications. The shanks are made with steel, heavy metal and carbide materials. Each shank has a female threaded end to accept any of the various cutting tool tips.

Tool tip change-over is quick and repeatable. Once the shank length is set in the ER collet, changing tool tips takes only a few seconds with repeatability of ± 0.0005 inch. With that repeatability, generally no additional tool offset is needed from tip to tip.

The system achieves this accuracy from the tool tip tool shank interface. It uses a simultaneous taper and face fit that provides a rigid connection. A taper in the tool tip fits a mating taper in the tool shank. In addition, a precision flange on the tool tip fits against the face of the tool shank. When the threaded tip is torqued into its seat, these two surfaces mate and provide simultaneous taper and face fit—like an HSK holder.

To change tool tips, the spindle is locked or a wrench is used to prevent shank rotation. The operator then removes only the tool tip using a wrench that fits molded or ground flats in the tip. The replacement tip is then finger tightened into the threaded tool shank leaving a small gap.

Using the wrench, an additional quarter turn of the tip seats it in the shank with taper and face contact. The visible elimination of the “gap” indicates the tool is seated. Right-hand rotation of the tool spindle keeps the connection secure for metalcutting
operations.

If carbide tool prices are impacting your shop and you need to reduce tool change times, this new system from Ingersoll may be worth a look. Its high repeatability, variety of geometries, tool shank modularity and quick-change capability are additional benefits to lowering a user’s carbide usage and more importantly, increasing productivity.