A custom step drill offers a big advantage over a conventional altered standard. A standard drill is produced with a web to suit its diameter. Grinding a step on an ordinary drill destroys the rake and causes the small diameter to have insufficient chip room.
Custom step drills are built to order with a flute form specifically designed to suit the small diameter as well as the large diameter. This method of manufacturing results in a more accurate tool. Proper rake and chip clearance result in less tool breakage and more satisfactory results are achieved.
Step Drills eliminate operations by drilling multi-diameter holes in one production step.
Two Flute Drills
The Two Flute Drill is a basic cutting tool, offering various helix angles, optional point angles, lengths and margin styles to fit your custom application requirements.
Two Flute Drills are versatile tools that can be adapted to cover a broad range of applications. Custom Two Flute Drills are necessary for custom applications where longer lengths, larger diameter, or special geometry is required. An important feature of the Two Flute Drill is the double/triple margin design which provides maximum bushing support. This results in a straighter and more accurate hole. The Two flute Drill is predominately used to remove large amounts of material. It is not considered a finishing tool unless part tolerances are not restrictive.
Three Flute & Four Flute Core Drills
Core Drills are a standard drill containing three or four flutes. It is used to enlarge previously drilled, punch cast, or cored holes.
Core Drills provide better hole size control and surface finish than two flute drills due to the additional cutting edges. The three of four lands provide superior guiding support, have a thicker web, and may be used with heavy feed rates. All Core Drills are manufactured to meet specific requirements with the specified lead angle, end sharpening, number of flutes, etc.
Step Core Drills
A Step Core Drill (3 flutes and 4 flutes) is a conventional core drill which has had a second diameter created by grinding down a portion of the larger diameter. These tools are used to enlarge previously drilled, punched, cast, or cored holes. Step construction limits regrind life in comparison to Subland construction but smaller diameter and greater diameter differentials are possible. More than two diameters are available for performing two operations in one production step.
The Step Core Drill is primarily used for Core Drill Counterboring, Core Drill Chamfering, Core Drill Reaming, Piloted Counterboring, or Spot Facing (Note that this style of tooling also applies to other combination tooling: Reamers, Counterbores, Spot Facers). All of the application are to enlarge existing holes, creating closer hole tolerances and/or surface finishes. The size optional program affords the opportunity to apply the correct tool geometry for your specific requirements.