A system comprising: - a welding electrode tip (3815T, 4015T, 4115T) for an electrical resistance welding electrode; and - a resistance welding fastener (3810, 3910, 4010) for fastening a first electrically conductive material to a second electrically conductive material using electrical resistance welding; wherein the welding electrode tip (3815T, 4015T, 4115T) has a bottlenose shape with a larger diameter portion proximate the welding electrode and a reduced diameter portion distal to the electrode, the reduced diameter portion having a radiused end for contacting the fastener (3810, 3910, 4010) during welding, wherein the radiused end of the reduced diameter portion has convex riveting surface (3815RS, 4015RS, 4115RS); and wherein the fastener (3810, 3910, 4010) comprises: - a cap, a shaft extending from the cap and having an end distal to the cap, the fastener (3810, 3910, 4010), when placed in a stack including first and second electrically conductive materials (11, 13) and positioned in electrical contact and subjected to an electrical potential applied across the stack, capable of conducting an electrical current, the electrical current causing resistive heating and welding to the second electrically conductive material at the end distal to the cap, the first electrically conductive material being captured between the cap and the second electrically conductive material after the end is welded to the second electrically conductive material, wherein the shaft has a solid cross-section between the cap and the end distal to the cap, wherein the cap has a concave depression (3812CS, 4010CS, 4110CS) therein capable of receiving the convex riveting surface (3815RS, 4015RS, 4115RS) of the welding electrode tip (3815T, 4015T, 4115T), wherein the radius of curvature of the concave surface (3812CS, 4010CS, 4110CS) of the cap approximates that of the riveting surface (3815RS, 4015RS, 4115RS) of the welding electrode tip (3815T, 44015T, 4115T). - a welding electrode tip (3815T, 4015T, 4115T) for an electrical resistance welding electrode; and - a resistance welding fastener (3810, 3910, 4010) for fastening a first electrically conductive material to a second electrically conductive material using electrical resistance welding; wherein the welding electrode tip (3815T, 4015T, 4115T) has a bottlenose shape with a larger diameter portion proximate the welding electrode and a reduced diameter portion distal to the electrode, the reduced diameter portion having a radiused end for contacting the fastener (3810, 3910, 4010) during welding, wherein the radiused end of the reduced diameter portion has convex riveting surface (3815RS, 4015RS, 4115RS); and wherein the fastener (3810, 3910, 4010) comprises: - a cap, a shaft extending from the cap and having an end distal to the cap, the fastener (3810, 3910, 4010), when placed in a stack including first and second electrically conductive materials (11, 13) and positioned in electrical contact and subjected to an electrical potential applied across the stack, capable of conducting an electrical current, the electrical current causing resistive heating and welding to the second electrically conductive material at the end distal to the cap, the first electrically conductive material being captured between the cap and the second electrically conductive material after the end is welded to the second electrically conductive material, - a cap, a shaft extending from the cap and having an end distal to the cap, the fastener (3810, 3910, 4010), when placed in a stack including first and second electrically conductive materials (11, 13) and positioned in electrical contact and subjected to an electrical potential applied across the stack, capable of conducting an electrical current, the electrical current causing resistive heating and welding to the second electrically conductive material at the end distal to the cap, the first electrically conductive material being captured between the cap and the second electrically conductive material after the end is welded to the second electrically conductive material, wherein the shaft has a solid cross-section between the cap and the end distal to the cap, wherein the cap has a concave depression (3812CS, 4010CS, 4110CS) therein capable of receiving the convex riveting surface (3815RS, 4015RS, 4115RS) of the welding electrode tip (3815T, 4015T, 4115T), wherein the radius of curvature of the concave surface (3812CS, 4010CS, 4110CS) of the cap approximates that of the riveting surface (3815RS, 4015RS, 4115RS) of the welding electrode tip (3815T, 44015T, 4115T).