Centerless Precision Grinding: An Innovative Approach to a Traditional Manufacturing Process


Resonetics’ centerless grinding process allows for an almost unlimited level of micro-scale geometries for mandrels, guidewires, centerwires and catheter components. With expert knowledge of process, machine manufacturing, automation, and over 100 grinding systems, Resonetics has one of the broadest and most comprehensive capabilities in the industry.

Precision, or centerless, grinding was invented in the early 1920s to support volume manufacturing of bicycle roller bearings. The technology first appeared in the medical device industry in the early 1990s, as the demand for guidewires increased with the advent of catheter-based surgical techniques. Centerless grinding enabled the production of guidewires by selectively removing the outside diameter to improve the flexibility required to navigate the circulatory system.

Many different materials can be precision ground, including metals, ceramics, and polymers. The key to grinding various types of materials is the selection of the grinding wheel material which can range from carbide to diamond. The process operates under an active coolant flow which maintains minimal heat input to the room. The most common raw materials used in the medical device market are stainless steel and nitinol, both in wire and tube form.

Precision grinding continues to develop in applications as medical device development engineers understand its benefits in terms of miniaturization and functional improvement.

The process can produce outside diameters from several millimeters to 25 micrometers or one-third the diameter of a human hair, with part lengths up to 5 meters long. Resonetics is able to use the process to grind complete parts on a microscopic scale.

Applications include catheter wires, loop or recovery wires, stylets, mandrels and assembly tools and core / guide wires for neurovascular, endovascular, interventional cardiology, peripheral vascular surgery , cardiac, CDRM and device tip leads.

The centerless ground wire often requires additional production processing to become a finished medical device. Resonetics can support this additional processing with value added services such as coatings (PTFE, EPTFE), laser welding, laser cutting, precision CNC machining, precision winding, microforming, heat setting, electropolishing and assembly.

Although the technology has been around since the 1920s, there are significant opportunities for process and equipment innovation. Resonetics has invested in the advancement of this technology and has developed a next-generation precision grinding platform that includes robotic loading / unloading and in-line geometry inspection. This new platform takes advantage of the latest advances in robotics to load and unload the machine, maximizing uptime and throughput. An online part geometry inspection system enables real-time part measurement with active feedback to the machine. This closed-loop approach allows tight geometry control with exceptional processing capacity. This new technology platform will help Resonetics support the next generation of medical devices manufactured by centerless precision grinding.

Content sponsored by Resonetics

Resonetics is the leader in microfabrication for the life sciences. The company’s LightSpeed ​​application development team can help you move your product through the development process with fast turnaround times, in-depth process knowledge, and dedicated equipment. The team will help your product go into production and ensure it is backed by the manufacturing resources needed to meet your production demands. Throughout the process, their world-class customer engagement group will ensure full communication with your team.

The main manufacturing capabilities of Resonetics include:

  • Laser treatment
    • Chopped off
    • Ablation
    • Welding
    • Drilling
  • Treatment of nitinol
    • Laser cut
    • Shape adjustment
    • Electropolishing
    • Polymer stent and frame liners
  • Chemical machining
  • Custom sensors
  • Sharpening
  • Metal fabrication
    • Stamping
    • Microforming
    • Winding
  • Thin-walled tubes and marking tapes

Resonetics focuses on innovation and invests heavily each year in internal R&D initiatives. This results in the development of numerous patents for specialized processes and equipment to support the manufacture of the next generation of medical devices. The company is ISO 13485: 2016 certified with facilities in the United States, Costa Rice, Israel and Switzerland.


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