Tillage tool

A tillage tool comprising:

• an elongated shank having an upper end and a pointed lower end portion, said pointed lower end portion having an elongated, tapered undercut, dove-tailed slot extending from the point at the lower end of the shank upwardly in the shank and tapering by diminishing in width from a location adjacent the point at the lower end of the shank as such slot progresses upwardly and rearwardly in the shank;
• and
• a hard metal wear insert mounted on the pointed lower end portion of the shank, said insert being substantially complementary in configuration to said pointed lower end portion and including an elongated locking key wedgingly engaged by said slot, said insert further comprising:
• an overlay plate protectively covering the upper surface of the pointed lower end portion of said shank, and having said locking key carried on the lower side thereof, and having a point at the forward lower end thereof;
• and
• a protuberant rib carried centrally on the upper side of said overlay plate and extending rearwardly and upwardly from the point at the forward lower end of said overlay plate, and disposed in substantially vertical alignment with said locking key, whereby the insert can be removed from engagement with said slot by impacting the upper rear end of said protuberant rib to transfer removing force to said locking rib and thereby disengage said locking rib from said tapered, undercut dove-tailed slot.