Releasable tubing pinch clamps of a generally U-shaped configuration are described. The embodiments include ones that prevent cross-clamping of the tube by various interlocking features on riser portions of the clamp. Methods and molds for making the pinch clamps are also described. For example, a pinch clamp can have a strip that curves so that its ends can be brought together by manually squeezing the strip at its end, which oppose each other as a result of the strip curve. The strip ends have locking edges or surfaces that cause the strip ends to interferingly engage with each other and lock together. The strip also has opposing pinch projections that can pinch a tube.