Grow1 Step Drill Bits are a convenient way to quickly drill various sizes holes without changing drill bits. Grow1 Step Drill Bits are titanium coated and are perfect for drilling into steel, copper, aluminum, wood, plastic, and many other materials. They are extremely useful for installing ebb & flow systems or for crafting your own hydroponic drip systems. Grow1 Step Drill Bits can create perfectly drilled holes 1/4" up to 1 3/8" in size.