How to Use the Billet Level Table for Offsets and Kicks
Proud Johnson Level billet level owner, John, in Red Bluff, California asks:
Just bought your magnetic billet torpedo level and noticed table of offsets and kicks, and reference to your web site. Found the table, but could not find an explanation of what, why or how to use the table. What have I missed?
And the answer is:
While bending conduit, the NEC (National Electric Code) limits the number of degrees between pull boxes. Fewer degrees of bend also results in an easier pull of wire through conduit. The limit is 360º between two boxes. These are referred as an offset.
An offset consists of two bends, the first to change direction of the conduit and the second to reverse that direction change. You end up with a "Z" shaped piece of conduit. The most common bend used is a 30º bend, followed by another 30º which results in a total bend of 60º. This is not always the case and you can have bends of 10º, 22º, 45º and 60º. Most hand benders are marked with these angles. The difference is in the multiplier, which is the chart on the back of our billet level packaging.
The multiplier is a number that the measured distance of the offset is multiplied by to obtain the distance between the two bends,and is usually memorized by the electrician for the common bends of 10º, 22º, 45º. Many conduit benders have the multiplier permanently stamped on the reverse side of the bender. Once the offset distance is measured; that measurement is to be multiplied by the appropriate multiplier from the chart on the back of our packaging.
For example, let's suppose that the distance needed is 3 1/2", and that we want to use a 22º bend. The multiplier for 22º is 2.7, and our distance is 3.5 (3 1/2"). Using a calculator, we find that 2.7 times 3.5 = 9.45". So when you mark your conduit you will have 9.45" between the two bends. (Center to Center distance between bends)
A 30º bend is exactly 2 on our chart and most electricians will bend 30º offsets because the math is simple and easy. It also results in unnecessarily sharp bends, which is harder for wire pulls and additional boxes.
Products Used: 1411-0600 6" Magnetic Billet Torpedo Level and 1411-0900 9" Magnetic Billet Torpedo Level
