A camera module to retain a smooth and easy focusing movement through components connected together by threads includes a lens bracket and a lens barrel. The lens bracket carries an optical lens and includes sidewall with a first internal thread. The optical lens includes sensor end. The sensor end includes a lateral surface with an external thread which corresponds to the first internal thread. The lateral surface defines several notches extending from the end of the lateral surface down through the external threads to reduce any clamping or high turning resistance between the internal and the external threads.