Laser Tube Cutting: Capabilities and Constraints

Lasers– notably fiber lasers – are particularly well-suited to medical industry laser tube cutting applications. From surgical instruments used in cutting and biopsy, to needles with unusual tips and side wall openings, or puzzle chain linkages for flexible endoscopes, laser tube cutting provides higher precision, quality, and speed than other cutting methods.

Tube cut geometries and features

L to R: Laser cut flexible shaft for endoscopy, shaver blade for arthroscopy and a needle cut for biopsy

But, is a laser right for your tube cutting application? Let’s look more closely at some of the capabilities and constraints:

• Material – Laser tube cutting is great for many of the materials commonly used in medical applications, including stainless steels (300 and 400 series, 17-4, 17-7), MP35N (cobalt-chrome steel alloy), and Nitinol. Other materials, such as titanium for implants and platinum iridium (Pt-Ir) commonly used for electrodes, can also be laser-cut, but may require little more setup time.
• Thickness– A 100W laser can comfortably cut a range of stainless steels up to 0.03-inch thick by altering the pulse width and frequency. For example, the thinner the material, the shorter pulse duration and higher pulse frequency needed to make the cut. A pulse width of 50 microseconds and frequency of 3000 Hz is a good starting point for 0.008-inch thick material, for example. Thicker materials may be cut with higher laser power.
• Geometry – Laser tube cutting offers great flexibility and works well with complex geometries. Unique cut features like off-axis cutting, enables product design for functionality without compromising manufacturability, but that’s not to say that laser cutting capabilities are not limitless. For example, some arthroscopic surgery shaver blades require a cut angle of up to 70 degrees to the distal part of the tube. This is not possible using the laser due to the large thickness increase caused by the angle coupled with the focus spot becoming an ellipse shape on the angled surface, significantly reducing the concentration of laser power and disrupting the cutting process.
• Speed – Laser tube cutting is an efficient process as the material being removed is minimal, and typical cut widths are less than 0.0015” for 0.015” thick material. Lasers cut parts one at time as opposed to wire EDM which stack cuts parts, but the overall cycle is still competitive, though of course part load/unload occurs more frequently. Laser cutting really excels compared to sinker EDM when cutting single sided tube features, in this instance laser cutting can be 2-3x faster.

Will lasers work for YOUR tube cutting application? Send your samples to us for a FREE evaluation.