How to measure fishing rod ferrules [Explained]

If you’re starting out with fishing rod or bamboo rod building, you’ve likely struggled with measuring the length of your rod ferrules. Struggle no more, as this article will answer all your questions!

What are ferrule rods?

Ferrule rods are hollow metal tubes that connect to form a fishing rod.

Often, they are used because they can be disassembled, allowing for a more transportable fishing rod. The individual tubes are usually replaceable, so if one ferrule breaks, you can replace it inside of having to buy a new rod.

Fishing rod ferrules are especially prevalent in fly fishing and bamboo fly fishing, as well as among DIY-enthusiasts who like to build their own fishing rod.

Additionally, ferrules come in sets of male and female. The female ferrule has a larger diameter than its accompanying male tube, which allows for the separate pieces to be attached.

How to measure fishing rod ferrules?

Drill bit sizes - Wikipedia

Note: Ferrules are measured by the nearest 64th of an inch. i.e. A ferrule’s measurement will be given as some number/64, or its simplification.

Measuring a fishing rod ferrule is as simple as getting the diameter of the female pipe’s hole. That is, you measure from inner end to inner end of the ferrule (don’t measure the metal!).

If you’re looking for a shortcut, you can also measure the diameter of the entire male ferrule, not just the inner hole. This works because the dimensions should measure to roughly the same amount.

To do this, you’ll need a dial caliper, and a little bit of math.

Measure the diameter of the ferrule, as discussed earlier. Digital dial caliper’s such as this one, tell you the diameter, eliminating the need for guess work. If you’re using an old-fashioned caliper, make sure to round to the nearest hundredths place at least.

Then, multiply the diameter you recorded by 64, or use this chart above. It’s alright if your numbers are a bit off from the chart, as long as you can still clearly tell which measurement matches your fishing rod ferrule.


If you don’t have a dial caliper or are unsure of your measurements, you can use this quick trick to measure your fishing rod ferrule.

Take out a set of drill bits and try placing them inside the hole of the female ferrule. Once you’ve reached a drill bit that is the same size, all you need to do is match the drill bit’s size to the ferrule.

Once you’ve gotten your fishing rod ferrules set up, you should learn how to hold your fishing rod.

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