Comprehensive Thinking Leads to Flat-bottom Holes

New drilling technology eliminates secondary operations, reducing cycle times

Figure 1—Drills with interchangeable heads can create a flat-bottom
hole in a single operation.

Figure 1—Drills with interchangeable heads can create a flat-bottom hole in a single operation.

Mechanical engineers are constantly searching for contemporary, fast, cost-efficient tools that will revolutionize their holemaking operations.

It’s only through comprehensive thinking initiatives that a new thought pattern can emerge, raising questions that inevitably lead to learning more about a given subject. Effective holemaking applications demand a keen understanding to meet the challenges they produce.

We took this comprehensive thinking approach to assist our customers and provide highly economical problem-solving options for holemaking production processes.

Over the years Iscar’s engineers have worked closely with customers and found that there is a growing need for flat-bottom hole production. This type of application is popular when creating a screw head pocket as well as when 90-degree spot facing and shouldering applications are performed.

The common way to produce flat-bottom holes is to drill the hole and then follow it with a milling or turning operation. A centre drill is required to drill a hole that will act as a centre of rotation for any possible further operations. Centre drilling typically is performed by using a tool setup with a specially shaped centre drill. This machining cycle demands at least two or three tools as well as two separate machining operations.

New tools featuring interchangeable drilling heads are an example of a new technology which, with a single tool, can create a flat-bottom hole (see Figure 1). When the tool is combined with a quick-change insert, operators can now eliminate several additional operations, consequently down-timing the procedure of creating flat-bottom holes.

New Drilling Heads

These drilling heads can be used with a standard SumoCham holder, on which the heads can be mounted. There is no need to buy an additional drill body, which makes upgrading the tool a fast and easy process.

Figure 2—The SumoCham-IQ has a drill head geometry that reduces
cutting forces at the initial penetration point.

Figure 2—The SumoCham-IQ has a drill head geometry that reduces cutting forces at the initial penetration point.

The drilling heads – designated FCP -- were designed with centre point geometry, enabling direct drilling capabilities by using a 5xD holder, although longer overhangs will demand pre-hole operations.

By eliminating the need for a pilot hole, this new technology shortens machining cycle time and the number of tools required for the drilling operation. This can provide a substantial cost reduction.

Other new geometries are suitable specifically for machining ISO P and ISO K material groups, which means that one drilling head can replace two other types, reducing the number of tools and stock items.

The major advantage of this type of tool is its ability to penetrate the workpiece material quickly and efficiently. The drill’s design is characterized by the “pin end” insert geometry that helps ensure a very steady entry into the workpiece material with a continuous smooth cut. It also creates a hole with high cylindricity values and good surface finish.

When looking for tools of this type, it’s important that they solve several machining issues. New tooling should improve peeling resistance and wear resistance, create predictable wear progression, run efficiently with minimum quantity lubrication (MQL), and lengthen tool life, all while producing high-quality surface finishes.

Specific to this type of machining are two additional drilling concepts from Iscar: SumoCham-IQ (see Figure 2) and Cham-IQ-Drill (see Figure 3).

These two families have a unique common cutting edge design that features concave sharp point geometry. The drill head geometry reduces cutting forces at the penetration point of the initial drilling operation. This is what shops should look for with this type of drill.

The drilling head geometry allows the drill to work with long overhangs without the need for a pilot operation, reducing machining time and tool inventory.

Drilling deep holes in cavities is no longer a barrier and has become substantially easy.

Figure 3—The Cham-IQ-Drill features a
cutting edge design that has a concave,
sharp point geometry.

Figure 3—The Cham-IQ-Drill features a cutting edge design that has a concave, sharp point geometry.

Arie Brodeski is product manager of holemaking tools, Iscar Tools, 905-829-9000, www.iscar.ca.