A thread brake includes a horizontal abrasion-resistant stripshaped flexible overlay on a resilient backing, pivotally supported about a horizontal axis at the half height of the strip, and a plurality of cylindrically curved braking elements supported at the ends of levers on a common shaft about which the levers are rotated to engage successively against the overlay. In another embodiment the strip is rocked about an axis displaced from itself into engagement with stationary braking elements.