The present application discloses improvements to support clamps for panels of glass and the like. An arrangement of two clamping halves (9000) each having a clamping surface (9001) and a locating component (9070) interlocking the two halves. Each of the two clamping surfaces are brought together by movement of the locating component through a range of positions, preferably lengthwise, such that portions of them are urged apart thus pressing together the clamping surfaces and securing the panel. In addition the first and second clamp halves include each an opening for a fastener (7014) within a flange (7010, 7012) such that the second opening is oriented approximately perpendicular to the first opening.