Spiral Fluted Large Bolt Knob Spiral Fluted Large Bolt Knob 1.6″Long 0.990″ Major Diameter Tapered up from a 0.380″ diameter at the threads These feature 5/16-24tpi threads that are 0.750″ deep with a .100″ recess These also feature 8 Spiral flutes for superior grip while not snagging Explore Firearm Solutions – J&A Outdoors
