Abstract: A one-piece compound lock for a power return measuring tape includes an elongated lock member slidably mounted in a casing that engages both the tape blade and the tape drum to resist unwanted movement of the blade. The lock member has a resilient locking tongue and is slidably engaged in grooves in the casing to guide movement of the tongue between an unlocked and a locked position. Drum locking tabs extend laterally from lock member. In the locked position, the locking tongue applies locking pressure to the tape blade and the drum locking tabs engage the tape drum to resist rotation.