Hi, Helixx - Based on the information you provided, we suspect Home Depot may have filled your order with the incorrect pipe. Those dimensions are more closely aligned to schedule 40 pipe. Given that pipe measurements have a + or - tolerance, it's very doubtful that our SDR-35 pipe would match your measurements. BTW, we're also curious how you took the measurements. Using a digital caliper is much more preferred than estimating it with a tape measure. If the pipe you received was indeed our 6" SDR-35 riser pipe, the ID would have have been 5.89" to 6.11". "Nominal" in the description, for the most part, means "in name only." Given all the above, we at least hope the product met your needs despite the dimensional question. Thanks for the review.