The function of a 45° elbow is the same as a 90° elbow, but the measurement of dimensions is different. The radius of a 45° elbow is the same as the radius of the 90° long radius elbow where ‘R’ equals 1½ D. However, the centre to face dimension is measured from each face to the point of intersection of the centre lines perpendicular to each other. This is due to the smaller degree of bend.

Note: See below for technical details…