Home / Milling / Mill Tooling / Boring Head, R-8, Diameter 4″, 3/4″ Bars, Flynn View cart “Arbor, Boring Head, 30 NMTB 1-1/2″ 18TPI” has been added to your cart. Boring Head, R-8, Diameter 4″, 3/4″ Bars, Flynn$225.00 1 in stock Add to cart Category: Mill Tooling Description Description Flynn 4″ Boring Head, R-8 Shank, Takes 3/4″ Boring Bars Related products Boring Head, R-8, Bridgeport, Diameter 3″, 5/8″ Bars Item # L61043A $149.00 Add to cart Boring Head, R-8, Diameter 4″, 1″ Boring Bars, Critereion L624R8 $349.00 Add to cart Boring Head, Straight Shank 1″, Diameter 2-1/2″, Erickson Tenthset $85.00 Add to cart Boring Head, Straight Shank, 2-1/4″ Diameter, Lincoln Machine Specialty $49.00 Add to cart