A spring clamp, comprises: a first body which includes a gripping portion and a clamping portion; a second body which includes a gripping portion and a clamping portion; a first pivot element which pivotally connects the first body and the second body; and a locking mechanism, which comprises at least a pair of friction pair components; wherein: the first friction pair component is provided on the first body, including a first friction pair element; and the second friction pair component is provided on the second body, including a second friction pair element (51, 151, 141); the friction pair component arranged in pairs has the first friction pair element and the second friction pair element (51, 151, 141) therein, which form a pair of friction pair elements and effect the locking function through rubbing against each other; wherein the locking mechanism further comprises an unlocking mechanism to release the lock between the first and second friction pair element (51, 151, 141); and wherein the locking mechanism further comprises an operation handle, which can be handled by a finger pressing the operation handle, so that the unlocking mechanism plays the role of releasing the locking between the first and the second friction pair element (51, 151, 141); and the rubbing of the friction pair elements occur in the plane perpendicular to the first pivot element axis; characterized in that the first friction pair element is an elongated sheet, having at least one main surface located in a plane substantially vertical to the first pivot element axis as a friction surface contacted with the second friction pair element (51, 151, 141). a first body which includes a gripping portion and a clamping portion; a second body which includes a gripping portion and a clamping portion; a first pivot element which pivotally connects the first body and the second body; and a locking mechanism, which comprises at least a pair of friction pair components; the first friction pair component is provided on the first body, including a first friction pair element; and the second friction pair component is provided on the second body, including a second friction pair element (51, 151, 141); the friction pair component arranged in pairs has the first friction pair element and the second friction pair element (51, 151, 141) therein, which form a pair of friction pair elements and effect the locking function through rubbing against each other; wherein the locking mechanism further comprises an unlocking mechanism to release the lock between the first and second friction pair element (51, 151, 141); and wherein the locking mechanism further comprises an operation handle, which can be handled by a finger pressing the operation handle, so that the unlocking mechanism plays the role of releasing the locking between the first and the second friction pair element (51, 151, 141); and the rubbing of the friction pair elements occur in the plane perpendicular to the first pivot element axis; characterized in that the first friction pair element is an elongated sheet, having at least one main surface located in a plane substantially vertical to the first pivot element axis as a friction surface contacted with the second friction pair element (51, 151, 141).