A 5D pipe bending is a pipe bend that the bend radius is 5 times the pipe outside diameter. What is 5D in bend pipe? The RADIUS of a 5D pipe bend is actually what is 5 times the nominal diameter. So if you had a 10" diameter pipe, the radius of the centerline of the bend would be 50 inches. How do you know a 3d or 5d bend? It is the radius of bend of the elbow with reference to a point,the point is determined by the intersection of two lines from the elbows socket end (which makes the shape of one quater of a circle). The bend ie; 1.5d,3d,5d,12d is determined from that point of intersection as a multiple of elbows diameter. 5D bend in pipe bending The 5D bend in pipe bending is an accomplishment in pipe manufacturing, and not all pipe companies can provide it.   The only alternative to finding a professional expert in 5D bends would be to attempt training your current employees to prepare the 5D bends for your business in-house. The cost outlay for this undertakin...