A sash lock housing enable screwless installation with respect to an opening in a sash window meeting rail, and includes a front, rear, and top walls. The top wall has a flat bottom surface. The rear wall includes first and second cantilevered ends, and a lip with a flat top surface being separated a small distance from the top wall's flat bottom surface that is configured to cause respective engagement with a top surface and a bottom surface of a top wall of the meeting rail, when the sash lock is inserted into the meeting rail opening. Also, the first and second cantilevered portions respectively engage first and second inside surfaces of a side wall of the meeting rail, to maintain the engagement between the top wall of the meeting rail and each of: the lip and the flat bottom surface of the top wall of the housing.

A forced-entry-resistant sash lock includes a housing, shaft/handle member, cam member, and secondary cam. When the cam member is in the unlocked position, rotating the shaft causes secondary cam rotation initially being independent of the cam member, and subsequently the secondary cam's first contact surface contacts the cam member's first contact surface causing co-rotation of the cam member and engagement of its cantilevered arm's first engagement surface with an interior housing wall's first engagement surface to cause deflection of the arm, and continued shaft rotation returns the cantilevered arm to the undeflected position, whereat forced counter-rotation of the cam member towards the unlocked cam member position is prevented by the contact between the first contact surface of the secondary cam and first contact surface of the cam member and contact between the second engagement surface of the cantilevered arm and the second engagement surface of the interior wall.