Zirconium 705

Zirconium 705: Premium Zirconium Alloy for Knifemaking

Originally developed for demanding aerospace, nuclear and chemical processing applications, Zirconium 705 is the benchmark zirconium alloy for premium custom knives. Alloying zirconium with niobium dramatically increases its strength over commercially pure Zirconium 702, making it suitable for spring-loaded components while preserving zirconium's exceptional corrosion resistance.

Compared to Grade 5 titanium, Zirconium 705 is approximately 50% heavier (6.56 vs. 4.43 g/cm³), has a comparable elastic modulus (~95 vs. 114 GPa), and achieves mechanical strength approaching that of Grade 5 titanium. Unlike Zirconium 702, its higher strength and improved spring properties make it ideally suited for frame locks, pocket clips, lock inserts, backspacers, bolsters and pivot collars.

One of Zirconium 705's defining characteristics is its ability to develop an exceptionally deep black oxide finish through controlled heat treatment. Unlike coatings or PVD finishes, this oxide is formed directly from the base material, making scratches far less noticeable while preserving the premium feel of solid metal.

The increased strength of Zirconium 705 also makes it noticeably less gummy during machining than Zirconium 702. It produces cleaner cuts, sharper edges and finer surface finishes, allowing intricate details and precision-machined components with reduced tool loading.