Have been asking around, it seems that I wasn't far enough wandering around my neighbourhood
..
It is still used in West Java as well.
Friends from Central Java (Pekalongan, Pemalang, and Tegal) and West Java (Garut, Majalengka, and Sukabumi) just said that it is still part of farmers tools.
The name itself definitely varies and sometimes in other places referring to different implement tools.
In Central Java, it's called as: cengkrong kembang turi (Javanese=> kembang ~ flower, turi ~ vegetable hummingbird (Sesbania grandiflora), arit bendo, and cengkrong. In this area, this blade is famous in sugarcane plantation. Where i saw this in Pekalongan/Petung Kriyono was in forest and coffee plantation.
In West Java: gaet, bengkrong, and ceblok (gaet kupas). People usually use this for weeding, cutting grass for their livestock, and harvesting their crops. There is gaet waluh (waluh~pumpkin) which smaller by the shape just perfectly similar.
Cengkrong in my place is referring to kind of this type of blade but the back also sharpened. Bendo in other part is referring to billhook, and also thick short and heavy parang