Possession
In New York City, open view carry of any knife is prohibited, unless being used for a lawful purpose under certain exceptions including “when such knife (a) is being used for or transported immediately to or from a place where it is used for hunting, fishing, camping, hiking, picnicking or any employment, trade or occupation customarily requiring the use of such knife;” Also, it is unlawful to possess a knife with a blade 4” or more in any public place, street or park. See New York City Administrative Code §10-133 Possession of knives or instruments.
The offense is punishable by a fine of $300 and/or 15 days imprisonment.
Prohibition on sales
In New York City it is unlawful for anyone to sell or offer for sale any folding knife with a blade of four or more inches which is so constructed that when it is opened it is locked in an open position and cannot be closed without depressing or moving a release mechanism. Exempt from this law are importers and exporters who ship these types of knives in bulk and the shipments remain in original unopened shipping containers. See New York City Administrative Code §10-134 Prohibition on sale of certain knives.
Violation of this prohibition is punishable by a fine of not more than seven hundred fifty dollars ($750) or by imprisonment not to exceed fifteen days (15) or both such fine and imprisonment. Any person violating this section shall be subject to a civil penalty not to exceed one thousand dollars for each violation.