Heavy duty threaded exhaust flange for use on all (hemi and standard) Harbor Freight Predator 212cc engines. Great for custom exhaust setups on generators, go karts, mini bikes, or garden equipment. Flange is CNC cut from heavy 1/4" steel plate to prevent warping, outlet pipe is NPT 3/4" pipe thread. Comes complete mounting hardware for a quality installation. Fit on Predator 212cc (6.5hp) Predator Hemi, GX160, GX200. also tested on Powerhorse 208cc... and many others! Flange center hollow to hollow 1"13 (see photos for details) THE MATERIAL OF THE EXHAUST FLANGE IS MILD STEEL, THE FEMALE AND MALE THREAD 304 STAINLESS STEEL. Finding the Correct Pipe Thread Size National Pipe Threads (NPT) Pipe sizes do refer to physical dimensions, but the plumbing industry standard for the sizes of pipe is not always as straight-forward as measuring the pipe. Measuring the pipe will oftentimes mislead you into choosing the wrong pipe, so do take care. The "pipe thread size" as shown in column 3 of the table below is measured and based on the inside of the pipe. But, to actually determine the size of a pipe, the outside diameter of each pipe or fitting must be measured and compared to the table for size identification. For example, a 3/4" NPT pipe thread has an outside diameter of 1.050 inches. Each thread size has a defined number of threads per inch (TPI). The 3/4" NPT pipe thread has 14 threads per inch. Both the TPI (threads per inch) and OD (outside diameter) of the thread are required for positive identification of thread size because several sizes have the same TPI.