Cast bronze alloys are listed chronologically by their nominal dimensions. Any continuously cast bronze tube is guaranteed “to finish to” its nominal size. To accomplish this, “clean-up” material is added to both the ID (inside diameter) and OD (outside diameter). For example, if you were to order a piece of bronze tubing with a nominal size of 1 x 3, you would receive a tube with an ID slightly smaller than 1 inch and an OD slightly larger than 3 inches.
When we speak of cast bronze tube “clean up” material, we are referring to the additional material added to the surface of the inside and outside diameters. With the removal of this additional material, you are able “to finish to” the nominal size. The exact amount of additional stock varies by both the alloy and size selected. The Cast Bronze Tube Tolerance Chart will help you understand the actual size of the most commonly used cast bronze alloys.