Abstract: An angle element for a welding and clamping table system includes an L-shaped profile, a base plate releasably fastened at one end of the L-shaped profile and provided with a system borehole of the welding and clamping table system, and a member releasably fastened at another end of the L-shaped profile and selected from the group consisting of a further such base plate and a clamping plate which is provided with several threaded boreholes to accommodate various hole patterns of quick-change clamps.

Abstract: A plate includes a surface having a slot designed for acceptance of a sliding block. The slot has a cross-section which in perpendicular relation to a longitudinal direction of the slot is a hexagon.

Abstract: An add-on element for a perforated plate having throughbores arranged in a regular grid includes an attachment part having a throughbore, an extension part, and a connecting element configured to secure the attachment part to an underside of the perforated plate by passing through a respective one of the throughbores of the perforated plate and the throughbore in the attachment part.

Abstract: A bolt for clamping abutting parts includes a bolt-like part insertable into openings of the abutting parts and including an external thread on a portion of an outer side of the bolt-like part. The bolt-like part includes a bolt component without external thread so that the bolt extends in each of the abutting parts at least partially with the bolt component without external thread. A threaded sleeve projects radially outwardly beyond the bolt-like part and is positionally adjustable by engaging an internal thread of the threaded sleeve in the external thread of the bolt-like part. A clamping element is provided inside the bolt-like part at an end of the bolt-like part in opposition to the threaded sleeve and is movable beyond an outer circumference of the bolt-like part through a bore of the bolt-like part. An actuator acts on the clamping element in order to clamp the abutting parts.

Abstract: A surface heating element for placement on a sub-floor and for making a heatable hollow space floor includes a plastic sheet having deep drawn protuberances forming spacers strengthened by ceramic support bodies or by a hardened finish material. The same sheet, or a second sheet connected to it, forms a carrier plate for carrying hot water tubes or other heating elements. The carrier plate may include deep drawn dogs, extending in a direction opposite to the protuberances, for holding the heating elements to the carrier plate; and a hardened finish material may be used to embed the heating elements.