Parts of unpowered (i) Rollers: cylindrical rollers are generally used which are made from ERW steel pipes with accommodate the antifriction bearings usually ball cast or fabricated end flanges bearings). The through axes are stationary and roller barrels can rotate freely. These rollers are called idler rollers. cylindrical objects (drums, pipes, round steel bars etc.). double tapered roll- For conveying ers or wheel rollers are used (Fig. 6.6.2)