Bostitch PT-MC Series Fasteners (PT-MC375SP38G) MCN Galvanised nails. This type of collation is ideal in construction environments where work can be kept free of collation debris. Diameter 3.75mm Head 7.2mm Length 38mm Profile Twist Ring shank nails have a series of rings punched into the surface of the shank. Again a difference in the diameter of the shank is produced making it even more difficult to withdraw the nail. Finish Galvanised Galvanising, or coating with Zinc, is the best way to prevent nails from corroding. The zinc does not protect the steel of the nail, but is corroded first. The thicker the zinc coating, the longer it will be before the nail is attacked. The thickest coating is called hot dipped and is applied by dipping the nails into a bath of molten zinc. Collation angle 33 Collation type Papertape Box of 4,000 Note MCN nails are only for use with MCN Tip.