摘要 |
FIELD: process engineering. ^ SUBSTANCE: proposed drill bit comprises body with lengthwise axis and at least two end face surfaces including guide element, lengthwise recess running from face surface along at least one drill bit body section, at least, two inserts adjoining said face surface, at least one said inserts may displace along aforesaid guide element and has cutout along said guide element on at least of face side, and cutting surface comprising at least one slot to receive cutting plate adjoining drill bit body edge, system to attach at last two inserts to drill bit body and at least one cutting plate secured in aforesaid slot and may be detached therefrom. At least one cutting plate in each said insert produced continuous bore in billet while at least one insert allows adjustment of drill bit diameter. ^ EFFECT: expanded performances. ^ 16 cl, 9 dwg |