JIS B4121:1985 pdfダウンロード。Indexable Inserts without Fixing Hole，with 0 Normal Clearance 1.Scope This Japanese Industrial Standard specifies indexable cemented carbideinserts without fixing hole，without chip breaker，and with 0° normal clearance angle to be used for indexable insert holders and the like,hereinafter referred to as the “tip”. Remark: It is preferable to apply this standard，with due changes having been made，to indexable inserts made of cermetand ceramics. 2.Definitions For the purposes of this standard，the following definitions apply : (1)basice inscribed circle ( a )An inscribed circle taken as the basis to define the height of corners and the size of inserts，and havingthe diameter equal...