Simpson 1/4" x 1-1/4" Tie Wire Wedge Anchor TW25114 SCHA Slide-Clip Connectors What does the 14/18 TPI

What does the 14/18 TPI designation mean on these blades

SDS-Max Shank: Compatible with SDS-max rotary hammer chucks for secure

Internal coolant tank built into casting base for use with coolant system

Drive Type: #2 Square

Dura-Carbide provides up to 2X more carbide material and withstands up to 1800 deg

Simpson 1/4" x 1-1/4" Tie Wire Wedge Anchor TW25114 SCHA Slide-Clip Connectors What does the 14/18 TPIThe Simpson Strong Tie TW25114 Tie Wire Wedge Anchor (1 4 in. x 1 1 4 in.), model number TW25114, is a wedge style expansion anchor engineered for reliable, fast installation in normal weight concrete or concrete over steel deck. Featuring a tri segmented, dual embossed clip and a 1 4 in. eyelet, this anchor is ideally suited for acoustic ceiling grid installation and sets quickly using only the claw of a hammer no special tools required. Key Features