Abstract: A strip coiler has an expandable coiling drum having on one end an outward flange which fits against an outward end flange on the end of a rotative drive shaft. The interfaces of the flanges have radial interlocking grooves and ridges. To hold the flanges tightly together, a collar encircles the flanges and has inward flanges embracing the outward flanges of the drum and shaft. The drum's flange and the corresponding inward flange of the ring form a bayonet joint so that by partial relative rotation of the ring and drum the drum can be removed and replaced. The flange of the collar which engages the shaft's flange is provided with a fluid pressure means so that when the bayonet joint is in its locked condition, the drum and shaft flanges are forced tightly together when this means is provided with fluid pressure. Release of the fluid pressure permits relatively easy partial rotation to unlock the bayonet joint for removal or replacement of the drum and its flange with respect to the flange of the drive shaft.