The Sinclair TiN Expander Mandrels are a great option for those who want increased resistance to abrasion over our Stainless Steel Mandrels, but don't want to feel the need to upgrade to our Carbide Mandrels. The Titanium Nitride coating process adds increased lubricity and abrasion resistance over the standard steel mandrels. Expander mandrels are made to 0.001" under bullet diameter. Originally designed to be used to expand the necks of brass prior to neck turning, these Mandrels can be used to set neck tension. Mfg: Sinclair International