An improved axle clamp is required, particularly for use with composite material leaf springs, to securely fix the position of the leaf spring relative to the axle or other wheel carrying member such as in the suspension system of an automotive vehicle. The present invention provides an axle clamp comprising a clamp base (1) and a wedge insert (2). The clamp base provides a platform portion (3) and substantially parallel side walls (4A, 4B) extending from the platform portion to form a channel adapted to receive the wedge insert. The inner surface of at least one side wall of the clamp base provides a channel-widening concavity (5A, 5B). The wedge insert has a platform portion (7) and substantially parallel side walls (9A, 9B) extending from the platform portion forming an inner channel adapted to jacket a mid-portion of the leaf spring (10). The outer surface of at least one side wall of the wedge insert provides a convexity adapted to engage and substantially fill the channel-widening concavity of the clamp base. According to one embodiment, an axle clamp assembly comprises the clamp base and wedge insert and further comprises a clamp plate (12) positioned over the leaf spring opposite the clamp base and adapted to be attached thereto to hold the leaf spring securely between them. Optionally, a resilient pad (11) is provided mediate the leaf spring and the clamp plate.