Abstract: In an inclination adjustment lock for partial areas of seats, such as seat backs, a first lock part is firmly attached to a first partial area and a second lock part is attached to a second partial area. Both partial areas are connected together so that they may pivot about a common pivot axis, and the second is mounted to the second partial area so that it may pivot about an axis parallel to the pivot axis, and so that it may be held via a locking pawl in a ratchet position. In the ratchet position, a toothed section of the second lock part engages with an opposing toothed section of the first lock part. The pressure angle of the tooth faces assuming increased loading conditions, such as during a crash, with the toothed section of the second lock part and their complementary opposing toothed section decreases as the separation from the axis 4a increases.