Nata come in various sizes and shapes, but most fit the description of a light brush hatchet or heavy camp knife. Common characteristics include thick spines and heavy blades with a bit of forward lean for chopping power, and often single beveled edges similar to Japanese wood chisels.
Materials: lawn mower blade steel, steel pipe, copper pipe, Sapele wood, Walnut, natural urushi lacquer, red Bamboo
Blade construction is muku/hon-yaki with a kiriha-zukuri profile and hira/kaku mune. The blade is 7.25″ long and 1 7/8″ deep with a 7/64″ spine, overall length is around 12.5″.
長さ/刃長 Nagasa: 185mm (blade length)
元幅 Motohaba: 47mm (blade depth)
重ね/元重 Motokasane: 5.5mm (spine thickness)
中心/茎 Nakago: 80mm (tang length)
柄長 Tsuka: 134mm (handle length)
[video=vimeo;131150935]https://vimeo.com/131150935[/video]
more here:
bladeforums.com/forums/showthread.php/1300147-Hon-Yaki-Nata
info on the geometry and making of a nata:
islandblacksmith.ca/2015/06/making-a-hon-yaki-nata/