Selecting the right countersink geometry and material can significantly impact tool life, surface finish, and overall productivity. Severance Tool Industries, Inc. manufactures a comprehensive range of countersinks, including single-, four- and six-flute designs in carbide and high speed steel, engineered to address a wide spectrum of machining conditions. With sizes from 1/8" to 3" and customizable angles, the company's standard tools support most applications, while specialty designs address unique production challenges.
"When machining hard or abrasive materials, carbide countersinks will often give 10x or more the service life of high speed steel tools," said a company spokesperson. "As a rule of thumb, consider carbide for production operations with cast iron, alloy steel or glass-reinforced plastics. High speed steel is generally more economical in low carbon steel and nonferrous machining applications. In automated production operations, the cost of changing a tool can exceed the cost of the tool. Consider long-running carbide in such situations."
The spokesperson continued: "In general, a six-fluted countersink will remove more material per revolution than will a four-flute or single-flute tool. While the single-flute countersink is slow cutting, it will work well in a nonrigid machining set-up. Four flutes provide more chip clearance than six do. This is a consideration in machining stringy materials such as some plastics and nonferrous alloys. Other factors being equal, the six-flute countersink will give more service life than the four-flute tool because the cutting load is distributed over more edges."
Resonant vibration is the cause of chatter in rotating cutting tools, the company noted. "Every tool/machine/workpiece system has natural frequencies at which such vibration will occur," said the spokesperson. "Severance countersinks are designed with staggered cutting edges, which inhibit the occurrence of resonant, or harmonic vibration. Tools with symmetrical cutting edges tend to multiply the frequencies at which chatter occurs and to reinforce the vibration. Chatterless design cannot change the natural frequencies of the system, but it takes tool geometry out of the problem."
What makes the Severance line unique, the company pointed out, is the number of proprietary and special tools it can supply to fit some specific applications:
- 3N1 drill points offer some cost-cutting opportunities to the creative tool engineer.
- CNC-K precision countersinks are used in numerical control and other preset tooling systems.
- Stop countersink systems are in use in the aircraft industry, where they are used with hand-held power tools to countersink rivet holes.
- Special tools that combine countersinks with drills, steps, pilots, radii, and other custom shapes are readily available from Severance. Send in a sketch or description for quotation.
"Very few tool rooms or sharpening services are equipped to recondition worn chatterless countersinks," said the spokesperson. "Our regrinding service is fast, competent, and economical."
For more information contact:
Severance Tool Ind., Inc.
3790 Orange St.
Saginaw, MI 48605
989-777-5500
severancetool@sbcglobal.net
www.severancetools.com