A tumbler is mounted for rotation around a trunnion with a screen fixedly mounted to a portion of the trunnion residing within the tumbler. A multiple blade paddle is mounted to a shaft that is rotatably supported through the trunnion. The paddle blades are formed with angular edges. As the tumbler rotates and the paddle rotates, powder is repeatedly dropped onto the screen to be sifted with the aid of the paddle. Rotating the tumbler further drops unsifted portions of the powder from the screen to mix with additional powder in the tumbler body. Thus, sifting and blending of powders is accomplished in one single operation.