The From the Anvil 1\" Rosehead Nails (1kg) Black Oxide are sold as a 1kg pack - this contains on average around 475 nails. Each nail is 25mm (1\") long and the head size is 7mm x 7mm. Black Oxide Nails The nails have a black oxide finish and can, in theory, be used internally or externally. Please note - being used externally they may be prone to grey staining and bleeding, especially in oak. Other Variations It is also available as 1 1/2\", 2\", 2 1/2\" or 3\" sizes - sold as separate products.