Fastening solutions to your most challenging problems.

In environments where harsh conditions abound, maintenance of corroded equipment is a costly concern. Often the weakest points in a system – the joints – are most at risk. And corrosion of the metal fasteners used can be a common reason behind such failures.

Non-metallic fasteners offer several benefits for demanding environments, not just for corrosion prevention, but also galvanic isolation and thermal insulation.

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Composite Fastening System


Durostone Fasteners threaded rod

A composite fastening system starts with the threaded rod. Unlike traditional bolts, a composite system uses open ended rods in conjunction with nuts.


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Composite nuts are available in hexagonal or square profile as standard. These come in standard metric sizes of M8 to M30. To meet higher tensile loads they can be supplied double-height or greater. Other sizes and inch threads available on request.


Durostone composite washers

In addition to standard applications, composite washers are also used for galvanic and thermal isolation. They come in standard metric sizes (M8 to M30) in either square or rounds profiles. Custom sizes available.



Composite tubes can also form part of the fastening system where required for galvanic isolation. They can be matched in sizing and material type to the rest of your fastening components.



A Grade for every need.

We exclusively utilise the Durostone fastener system, from Rochling. It offers many excellent quality material grades and has been in use for decades in many tough environments.

Here is a range of different grades in a variety of formats. From EPR S5 for chemically aggressive and maritime applications, to UPR S19 which has very high dielectric properties for electrical uses, to name but a few.

Insulect can assist with evaluation and recommendations on what solution is best for your situation.

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Density of circa 2g/cm3 makes composites about 1/4 the weight of steel.

High tensile strength


Compared to thermoplastics, Durostone has a six fold higher tensile strength.



Particularly resistant to aggressive fluids, gases, oils. And highly UV and weather resistant.



Durostone has an insignificant water absorption rate of < 5% of weight.



All grades are electrically insulating and non-magnetic. Some offer partial discharge free and non-tracking too.



Composites have very low thermal conductivity (0.3 W/mK), similar to mineral wool insulation.


Tensile strength and pre-loading.

Durostone composite threaded rods and nuts have a relatively high coefficient of thread friction compared to steel.

This can cause high torsional loads for the rod even at low pre-loads. These high torsional loads can lead to premature failure, prior to reaching the tolerable maximum pre-load.

To ensure the expected high strength of Durostone threaded rods, we recommend the following simple measures:

  • Reduce thread friction by oiling the thread, teflon coating the rods and nuts, or coating the threads with a suitable adhesive.

  • Pretension components, allowing a tension free tightening of the screw.

  • The use of a torque wrench for uniform clamping.



Composites Materials

Our range is much bigger than we can show here. Give us a call for detailed technical information.


Why Insulect is the right choice for Composites.


Quality Custom Materials

With our materials partner Rochling of Germany, we provide some of the best composites available. They have a large standard range and the ability to offer special formulas to customer needs.


Local Manufacturing

Modern, well equipped facilities in three states (QLD, NSW, VIC) give us the flexibility to meet varying customer demands, whether for highly complex or high volume projects.

Expert Advice

We've been in the engineering materials world for over two decades. Our team can work with you to solve a wide variety of challenges and technical applications.


Local Support

Whether you have a new enquiry, are planning a large refurbishment or need support for the life of a project, we are just around the corner and can support you all the way.


More Industrial Materials:


Electrical Materials


Thermal Materials


Mechanical Materials


Pultrusion Composites



Find out more today.

Whether you're operating a Transmission or Distribution network, a Generation plant, or Industrial site, we would be glad to have a no obligations discussion to understand how we can help your organisation.