These are specific tools that match the worm shaft with sharpening allowance . Worm Hobs are generally designed for plunge cutting however tangential feed hobs can be had on request . Hobs are manufactured in shell or shank design with straight or spiral gash . Lead angles upto 45' are available . Worm hobs are usually made in Class 'C' but can be supplied in Class 'A' & 'B' on specific request.