【5 Size Assorted Pipe Plug Fitting】The pipe fitting plug assortment set contains 1/8" 1/4" 3/8" 1/2" 3/4" pipe plug fittings, each size of 6 pieces, a total of 30 pieces. The pipe plug socket fittings are packed by sizes in a sturdy storage container for easy, convenient, hassle-free storage. 【Carbon Steel Material】Made of premium carbon steel with superior acid resistance, anti-corrosion and high strength, suitable for use in wet environments, standard threads that are not easy to slip. Burr-free male pipe threads will not harm your pipeline. 1000 PSI maximum pressure and low magnetic permeability, so our NPT pipe plug are strong enough to use under pressure for long time. 【Seal Design】Our hex head pipe fitting socket are designed to create a tighter seal for masking threaded holes and sealing pipes to prevent leakage of air, steam, gases, water, oil and fluids under pressure, which they be tightened securely without stripping and fit securely in different pipe materials. Great for closing the ends of the pipe or tube. 【Hex Drive】Male National Pipe Taper (NPT) threads for connecting to female threaded pipes or fittings. Countersunk plug with a hex drive for closing the end of a pipe or fitting, quickly installation and removal. pipe plugs are external threaded, just tighten with a wrench. Please use a sealant (tape or paste) to help seal before installation. 【Wide Application】An important mechanical fasteners are commonly used to seal holes in machinery, fittings or pipes, be extensively used for commercial, automotive, boats, industrial, sanitary pipes and fittings. Not only Work great on preventing leakage of air, steam, gases, water, oil and fluids under pressure, but also great for blocking off intake manifold water ports, water pump ports, water temp and oil sender holes, engine block holes, etc.