Profile: Knobs Direct Inc. is a source for industrial plastic knobs and handles. Our product line includes ball knobs, knurled knobs, bar knobs, three arm knobs, four arm knobs, seven arm knobs and small grip handles. Our wide selection of high quality ball knobs include phenolic or rubber materials in diameter sizes including 3/4", 1", 1-1/4", 1-3/8", 1-3/4", 1-1/2" and 2". We offer a selection of neoprene soft grip ball knobs. We supply knurled knob with internal thread and external threads.