A surface covering plank (10, 10',10") comprising: a resilient composite sheet that is flexible and having an overall thickness of 5 mm or less, and having a planar upper surface, and having four sides, an upper surface, a lower surface, and an overall thickness, and said composite sheet comprising at least one base layer, wherein said at least one base layer comprising at least a homogenous blend of a thermoplastic polymeric material and a filler in resilient sheet form, wherein opposite sides of the composite sheet comprise a first tongue on a first side and a first groove on the opposite second side, wherein the first tongue and first groove have complementary shape to each other to be interlockingly engageable at a joint seam with a corresponding groove or tongue on an adjacent floor plank, wherein first tongue comprises a tongue tip which is a portion of the tongue that extends distally beyond the joint seam , and wherein the first groove comprises a groove deck which is a portion of the second side located between the join seam and an outer most edge of the tongue and above a line , which is at a point where an outer tip of the tongue and the groove meet, in an engaged position of the tongue and the groove, wherein the tongue/groove profile has a clearance area when the tongue of one panel is joined to the groove of an adjoining panel and said clearance is at the groove deck /tongue tip area, that a tongue top upper surface slants, the clearance begins at approximately a vertical plane that is perpendicular to the upper surface and at the joint seam, characterized in that a cross-sectional area of the tongue tip and the cross-sectional area of the groove deck is within 15% of each other, and the clearance ends at the outer most edge of the tongue. a resilient composite sheet that is flexible and having an overall thickness of 5 mm or less, and having a planar upper surface, and having four sides, an upper surface, a lower surface, and an overall thickness, and said composite sheet comprising at least one base layer, wherein said at least one base layer comprising at least a homogenous blend of a thermoplastic polymeric material and a filler in resilient sheet form, wherein opposite sides of the composite sheet comprise a first tongue on a first side and a first groove on the opposite second side, wherein the first tongue and first groove have complementary shape to each other to be interlockingly engageable at a joint seam with a corresponding groove or tongue on an adjacent floor plank, wherein first tongue comprises a tongue tip which is a portion of the tongue that extends distally beyond the joint seam , and wherein the first groove comprises a groove deck which is a portion of the second side located between the join seam and an outer most edge of the tongue and above a line , which is at a point where an outer tip of the tongue and the groove meet, in an engaged position of the tongue and the groove, wherein the tongue/groove profile has a clearance area when the tongue of one panel is joined to the groove of an adjoining panel and said clearance is at the groove deck /tongue tip area, that a tongue top upper surface slants, the clearance begins at approximately a vertical plane that is perpendicular to the upper surface and at the joint seam, characterized in that a cross-sectional area of the tongue tip and the cross-sectional area of the groove deck is within 15% of each other, and the clearance ends at the outer most edge of the tongue. <EOS>