Nickel Systems stocks Grade 2 titanium fasteners including hex bolts, hex nuts and washers, primarily in 1/4” through 5/8” diameters. Titanium fasteners in Grade 5 and Grade 7 are by special order.
Grade 2 titanium is commercially pure titanium. When its surface is exposed to oxygen or moisture, a new corrosion resistant layer of titanium oxide is created. It resists both acids (oxidizing and mildly reducing) and alkali. Usage of Grade 2 titanium fasteners in marine environments is common. Grade 2 titanium fasteners are used for orthopedic and dental implants. Although non-toxic, its chips are extremely flammable.
The advantage of Grade 5 titanium is that it is heat treatable. Although it is more than twice as strong as Grade 2 titanium, its corrosion resistance is not quite as good.
A small addition of palladium is used to create Grade 7 titanium. This addition gives it better corrosion resistance than Grade 2 titanium fasteners in cryogenic and highly acidic environments.
Typical Tensile Strength (at room temperature in KSI)
Grade 2 Titanium: 55
Grade 5 Titanium: 135
Grade 7 Titanium: 55
Typical Chemistry (% by weight)
Grade 2 Titanium: Ti 99.2
Grade 5 Titanium: Al 6, Fe .15, Ti 89, V 4
Grade 7 Titanium: Pd .2, Ti 99