Abstract: An improved locking bolt for a T-handle assembly is provided. The locking bolt has an associated security collar which encircles the bolt and prevents axial movement of the T-handle housing relative to the bolt when the threaded end of the bolt is threaded into the door frame of the closure. The security collar is held in place by a pin which extends through corresponding apertures in the collar and the bolt. A ball bearing is positioned in a recess formed in the bolt to prevent axial movement of the collar on the bolt in the event that the pin is defeated. The bolt and the security collar also act as a secondary locking mechanism by preventing rotation of the bolt when the lock is released, a special wrench being required to rotate the bolt after the lock is removed.