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 375mm head 72mm 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