Flex-Matched Ferrule Info
These are joiners, also known as ferrules designed to join fiberglass rods and tubes.
Traditionally steel or Aluminium tubes have been used to join pultruded rods and tubes.
So why Flex-Matched.
1. Metal joiners are much stiffer than the fiberglass rods. This causes a huge stress concentration at the entrance and the metal tends to bite into the rods damaging the rods and severely limiting the life span of the rods.
This is particularly problematic at elevated temperatures ( Greater than 55 deg C)
The Flex-Matched Ferrule eliminates this problem at room temperature and increases the temperature tolerance of a joined rod.
For example : a 6 mm Vinyl Ester Glass Rod with a steel ferrule bent in a circle of 800 mm diameter will fail at the ferrule at around 55 deg C
The same rod with a Flex-Matched Ferrule fails at around 80 deg C.
2. They look better as they bend or flex in a similar way to our Fiberglass solid rods.
3. Being made from very high quality injection molded fiber reinforced plastic, they are extremely tough and will never corrode.
Stock Sizes available:
Smaller Loose fit both sides
3 mm to 3 mm ( 3.2 mm ID ) for loose fit at both ends
4 mm to 4 mm ( 4.2 mm ID ) for loose fit at both ends
5 mm to 5 mm ( 5.2 mm ID ) for loose fit at both ends
6 mm to 6 mm ( 6.3 mm ID) for loose fit at both ends
Interference fits sizes kept in stock:
( See pic at end for further dimensions)
The larger size Flex-Matched Ferrule are designed to be a press or interference fit on one side and a loose fit on the other.
The smaller side needs to be heated and pressed onto the rod. We do offer the service of cutting rods to length and fitting a ferrule in this manner.
The Flex-Matched Ferrule becomes permanently attached to its rod on one side.
Left size below is the nominal size of the rod that the ferrule is fitted onto.
The right number is the ID( Inside Diameter) of the ferrule hole for a loose fit.
7 to 7.2 mm ( E Body)
8 to 8.2 mm ( D Body)
10 to 10.2 mm ( C Body)
11 to 11.2 mm ( B Body )
12 to 12.2mm ( B Body )
14.6 to 15 mm ( A Body ) Fits 14.6 mm round rod and the X profile rod.
Note the 14.6 to 15 matches the X profile stiffness, not the 14.6 solid bar stiffness.
Stepped size Flex-Matched Ferrules
Our Flex-Matched Ferrules ( joiners) bodies can also be used to join rods or tubes of different sizes. For example an 8 mm to 14.6 , or 10 to 12 mm.
These stepped sizes are custom made to order using the same injection mold cavities but with different sized holes down the center.
When used to join different size rods, the flex can no longer match both rods as these are very different.
Further customization available:
The Larger 7 mm upwards sizes are based on 5 body sizes.
We label then A,B,C,D.E ( biggest to smallest)
In some applications it may not be necessary to match stiffness. We can make bigger holes down the center than the standard sizes listed above.
For example:
In the standard Flex-Matched size range we use a large A size body with a 14.6 to 15 hole former up the middle to match the stiffness of an X profile.
To make the 14.6 to 8 reducing ferrule, we can use a B or even C size body with the same hole.
The large A size body is not needed as we only want to match the stiffness of the 8 mm, so we can use a C body with a 15 to 8 mm hole.
Sizes stocked
As of November 2020 we only stock one stepped Ferrule
15 mm to 8 mm in a C body. This is an interference fit on the 8 mm and a loose fit of a 14.6 or X Rod.
Please contact us if you need a different size.
We will add to these stocked sizes as demand develops.
Outside Dimensions of Larger Interference fit / stepped range: