Simpson Double 3 1 2 x 16 Heavy Top Flange Hanger for SCL HGLTV416 2 Dust Collectors & Accessories flat bottomed hole without tearout flat bottomed hole without tearout the negatively ground curved spurs and balanced centre point on this bit address exactly that requirement Patented Reinforced Core Flute The reinforced core structure maximizes energy transfer from the rotary hammer into the drill bit tip Structural composite lumber (SCL) header connections requiring high load transfer The Simpson Double 3 1 2 x 16 Heavy Top Flange Hanger for SCL is a heavy duty engineered connector built for structural composite lumber header connections that demand reliable