Brad nails for Bostitch models BT200K-2 and SB1850BN nailers. Both 15 to 50 mm maximum. Gauge/Diameter (mm) 18 GA Length 40 SKU BT1340GA Finish GALV Description MINIBRADS 40 GALVA 5M Qty per box 5000 BT Series galvanised 18 gauge brad fasteners for use with the Bostitch Finish Bradders. Joined with an adhesive coating that holds the brads together. Finish nails (brads) are normally of a rectangular cross section instead of being round. Their diameters are less than the coil and stick nails, and are primarily used for finish and trim work in the construction and joinery industries.