How to Determine if Custom Titanium Bolts Are Made of Titanium?

Titanium Alloy Bolts are fasteners made from titanium alloy materials, valued for their low density, lightweight properties, high strength, and corrosion resistance, making them ideal for industrial applications in extreme environments. They are widely used in industries such as electroplating, chemical processing, aerospace, and marine aquaculture, often requiring custom machining based on client specifications, though they come at a relatively high cost. So, how can we determine whether a custom titanium bolt is genuinely made of titanium alloy? The following methods can be used for verification:

5. 1.      Visual and Marking Inspection

   l  Color and Luster

   Titanium exhibits a natural metallic gray-white appearance, typically displaying either a mechanically polished or satin-brushed surface finish. Compared to stainless steel (bright white) or aluminum (light grayish-white), titanium demonstrates a darker hue while maintaining non-magnetic properties. Titanium Screw characteristically present a brighter finish with a distinctive cool-toned metallic luster, free from visible surface imperfections.

   l  Identification Marking

   Check the material specification on the packaging label, which typically indicates the titanium alloy grade, such as: Ti-6Al-4V, GR5, Ti, TC4, etc.

   2.      Physical Property Testing

   l  Magnetic Permeability Testing

   Titanium and its alloys are non-magnetic, showing no attraction when a magnet is brought near. However, while 316 stainless steel is also typically non-magnetic, it is significantly heavier in comparison.

   l  Density Testing

   Titanium has a density of approximately 4.5 g/cm³, being significantly lighter than steel while slightly heavier than aluminum. This characteristic allows for preliminary identification through manual handling or weight measurement.

   l  Hardness Testing

   Pure titanium is relatively soft, with a Vickers hardness of approximately 150–200 HV, while titanium alloys typically exhibit a higher hardness of around 330 HV. However, accurate measurement requires professional hardness testing equipment (e.g., Rockwell or Vickers hardness testers), as manual assessment or visual inspection cannot reliably determine these values.

   3.      Professional Testing Methods

   Through spectroscopic analysis or salt spray testing. Of course, when conditions permit, using spectroscopic analysis equipment can directly determine the primary elemental composition (Ti, Al, V) of the titanium alloy, representing a relatively accurate identification method. Alternatively, if the product maintains its original appearance without rust formation after prolonged salt spray testing, it can also be reasonably determined to be a titanium alloy screw.

6. 

The above outlines basic titanium identification methods; however, given titanium's unique material properties that significantly influence performance characteristics, accurate material verification requires specialized testing by certified laboratories. Titanium fasteners are primarily categorized into two types: commercially pure titanium (CP Ti) which exhibits excellent ductility and oxidation resistance but limited mechanical strength, and titanium alloys that incorporate strategic metallic additions to enhance specific properties - with substantial cost differences existing between these material grades. Consequently, when procuring custom titanium bolts, material selection must be carefully evaluated against the intended operational environment and application requirements to ensure optimal performance-to-cost ratio.