On February 4, 2026, a medical device contract manufacturer in Minneapolis, Minnesota, validated the micro-cutting performance of a tungsten steel cutting blade on nitinol guidewires of 0.35mm diameter, because surface defects in cardiovascular devices can trigger thrombus formation. Using a custom micro-slitting station, the tungsten carbide blade produced cut end surfaces with an average roughness (Ra) of 8.7 nanometers, as measured by white light interferometry. This surpassed the ISO 13485 requirement of Ra ≤ 25nm for Class III implantable devices. The blade maintained this finish across 8,500 consecutive cuts without any measurable wear on its 10µm tip radius, whereas competitor-grade blades (unnamed generic brands) exceeded the roughness limit after 2,000 cuts. Additionally, the ultra-hard cutting blade eliminated micro-burrs that previously required electropolishing, saving the manufacturer 450,000. The company now plans to qualify tungsten steel slitting blades for other micro-medical applications, including hypotube cutting and stent strut slitting.
