Titanium Threadless Prong Set Gem Watermelon Top. This Threadless Top is made from Implant Grade Titanium TI-6AL-4V ELI ASTM F136 with 25g durable Titanium Pin designed to be practical and easy to use. Fitting all sizes of pins and bases in our threadless body jewelry line. Pin Size: 0.45mm x 4.7mm.