Nagasa: one Shaku two Sun four Bu.
Sori: 3 Bu

Itame with Masame - O-Mokume - having profuse Ji-Nie over strongly standing Hada. O-Midare in wide Nioi-Fukai with running Sunagashi having thick Nie and Ara-nie. Deep Boshi is Tsuki-agi where the Kaeri runs down the back. An extraordinarily high degree of excellence. 

A superior and wonderful sword. 

Solid gold double Habaki with Tokugawa Family Mon
This very sword is presented on page 388 of the Nihonto Zuikan and is listed as "Superior Quality".

This was a long possession of the Utsunomiya Family of Omi Province. 

The reasons are several. Hankei was from Mikawa, Iyeyasu's home province. 
He was perhaps the greatest gun smith of the era, known as an utter genius. His gun-smith name was Noda Denjiro Kiyotaka. 

Scholarship has argued why such a great Gun smith should then make swords. Iyeyasu commanded him to revert to make guns for the Osaka Summer and Winter Campaigns. 

Hankei's work is rare, and according to the Japanese "very, very" rare. His group is small; his student, Hansho's work is rare and the work of Seikei almost never found. See Juyo Hansho Tanto