Related על חולין 9:3

One who flays the skin of an animal [by pulling it from the feet toward the neck (see Jastrow, "מרגל")] and [then] slaughtered [the animal], his slaughter is valid. A detached tooth or a detached fingernail -- we may slaughter with it (Hul. 1:2). A scythe [may only be used to slaughter] by [cutting] in the direction it normally traverses (alt., moving it forward) (ibid). Beit Shammai invalidate it and Beit Hillel validate it. And if the teeth of the scythe are filed away, behold, it is like a [regular] knife. One who [intended to] stick a knife in the earth by throwing it [באַטְלֵק not באטלס, see Jastrow] and slaughtered with it, his slaughter is invalid. A knife that has many notches (lit., "notches notches"), behold, that is like a saw. If there is between one notch and the next notch [a space equivalent to the space] between the two [simanim] in the neck, his slaughter is valid. [If] there is but a single notch, if it would get caught, the slaughter is [nonetheless] valid, [but] if it strangles, it is invalid.