OSG Threading Tap - BSPT Spiral Flute HSS-E - Steam Oxide Coated - Blind Hole - 1/8 x 28Engineered for BSPT threading in blind holes, the OSG BSP Spiral Flute Threading Tap (1 8 x 28) delivers precise, reliable BSPT threads when access is limited to deep or recessed holes. Crafted from cobalt enhanced HSS E and protected by a Steam Oxide coating, this tap is built for durability and steady performance in challenging machining tasks. Size and threading: 1 8" nominal size with 28 threads per inch (BSPT), designed for blind hole tapping.