Tongue and groove bricks are pressed when half-dry and are therefore extremely true to size. They can be used for the construction of flues and also for the insulation of a furnace. Corner bricks with a 90° or 135° angle facilitate quick construction of corner walls. The groove and the tongue create positive-fit connections into which already integrated clasp holes can be inserted in order to tighten the clasps even more. The complete range with complete and half boards as well as corner boards is available in the category 250x200 in three thicknesses: 40, 50 and 60mm. Grooves and tongues of all thicknesses are compatible with each other and can also be combined with Wolfshöhe’s Double Groove Bricks.