Ti-99.6, or ASTM Grade 2, is the workhorse of the commercially pure titanium family and by far the most widely produced and used CP grade in industry. Like the other unalloyed grades, it contains no deliberate alloying additions — its properties come entirely from tightly controlled interstitial content, principally oxygen and iron. Grade 2 allows slightly higher oxygen and iron than Grade 1, which raises its strength a step above Grade 1 while still leaving it comfortably ductile and easy to form and weld.

That balance of moderate strength, good ductility, excellent weldability, and outstanding corrosion resistance is exactly why Grade 2 has become the default choice for titanium piping, heat exchangers, pressure vessels, and process equipment in the chemical, desalination, and pulp-and-paper industries, as well as marine hardware and architectural applications. Its corrosion resistance comes from the same thin, self-healing titanium-oxide film found on every CP grade, giving it near-immunity to seawater and most oxidizing and mildly reducing chemical environments without the added cost or complexity of alloying.

Grade 2's machining behavior follows the same rules that govern every titanium grade. Its thermal conductivity sits far below steel's, so cutting heat stays concentrated at the tool tip instead of exiting with the chip, and tool-tip temperatures climb quickly even at moderate cutting speeds. That heat, combined with titanium's chemical affinity for common tool materials once temperatures rise, promotes adhesion and edge buildup rather than a clean, continuous shear.

Its low modulus of elasticity means the material deflects under cutting pressure more than steel does at equivalent force, so a rigid setup — short tool overhang, solid workholding, minimal stickout — matters more here than it would machining plain carbon steel. Titanium also work-hardens where a tool rubs instead of cutting cleanly, so feed needs to stay consistent and adequate to keep the edge biting into unhardened material rather than skating across a glazed surface from the previous pass.

Because Grade 2 has somewhat higher strength than Grade 1 but is still unalloyed and free of any beta phase, it sits in the middle of the CP machinability range: easier to cut than any alpha-beta or beta titanium alloy, but slightly more demanding than Grade 1 in terms of achievable speed and tool wear. Sharp, positive-rake cutting edges, moderate speeds, steady feeds, and generous coolant remain the fundamentals for good results.