bigHead

bigHead-JackNut® combination solves composite panel fixing problem

One very recent development from bigHead is the bigHead-JackNut® fixing.

As with many requests we receive this fixing was developed to solve a specific problem, how to affix into a single skin of a composite foam-filled sandwich panel without the requirement for bonding.  The fixing also needed to be capable of spreading applied loads onto a very thin substrate (3mm thick), should permit installation into the finished composite panel with access from one side only and without the need for any specialised install criterion.

bigHeads' solution was to take an already successful fixing solution for thin, lightweight materials, the 'JackNut®' and marry this technology with that of a bigHead.  The result below clearly illustrates how bigHead's versatile, flexible manufacturing capabilities and approach to problem solving has many facets.  JackNut® is a registered trademark of Emhart Teknologies.

Combining bigHead technology with that of the JackNut® brings the following features to the end-user:

• Capable of being installed from one side of the panel
• Fastens into blind holes
• Fastens securely despite burrs or uneven substrate
• Hole size tolerant
• Provides large 'open-side' bearing area
• Provides large 'blindside' bearing area
• Will not distort or deform soft plastics or thin sheet
• Capable of accommodating a wide grip range
• Can be set with manual or pneumatic tool
• Available in Mild Steel + BZP only & in sizes M4, M5 & M6 Metric coarse thread form
  

If you are interested in this or any other products in our range, don't hesitate to call us; our contact details are available via the 'contact us' link on the home page.

bigHead solves corrosion problem with unique fixing solution

bigHead was recently approached by a leading specialist in phenolic resin-based syntactic foam insulation and fire protection systems to solve a problem that traditional fixings were not.  To provide a solution which removed the need to weld-on insulation retention pins required to hold the protection system in place.  Traditional methods of welding on the pins was leading to problematic corrosion issues particularly on offshore applications, resulting in a customer-driven need to find an improved fixing solution.

bigHead rose to the challenge, again proving how their manufacturing flexibilities and technical know-how approach to solving problems like this was well within their capabilities.

The solution: a 316 stainless steel bondable fixing that completely removes the need for welding and the implied cost and corrosion issues they bring; utilising bigHead's unique perforated head design to ensure high load-carrying characteristics and capable of being applied to many substrates with ease.

Following initial bonding of fixings to the downward-facing steel structure the bigHead 'Butterfly' design of the retainer-bracket can then be over-sprayed with a wet-plaster system, thus ensuring complete protection of the fixings from heat, fire and other environmental conditions.

If you are interested in this or any other products in our range, don't hesitate to call us; our contact details are available via the 'contact us' link on the home page.

 

bigHead Weld versus Clinched - which is stronger?

 
Both clinching and resistance welding are tried and tested fastening technologies used in a myriad of industrial applications.  Both methods achieve good results, but which is stronger?  

In an effort to answer this question bigHead recently carried out comparative tensile loading tests on clinched fasteners of equivalent material properties and dimensions to that of a bigHead fixing.  The results clearly show that resistance welded fasteners can accommodate a 66% higher tensile load than equivalent clinched fasteners.  The superior performance equates to an additional 200 Kgf of loading before the product may physically fail.  Clinched samples failed above 3.3KN and bigHead samples failed above 5.2KN.

 

Fig. 1 and 2 below show both clinched and resistance welded fasteners after testing.  Both fastener groups have been tested to destruction by the application of a tensile load applied axially to the stud.
The example selected for test was a low carbon steel fixing with a diameter 30mmx1.2mm head and M6x12 centrally affixed stud.

   
 Fig. 1: clinched fasteners after tensile testing                      

 
Fig. 2: bigHead fasteners after tensile testing; note that material has remained attached to the stud, having been torn away from the head; the bigHead benchmark test….see below

Tensile loading to destruction is the benchmark test method used by bigHead for each and every production lot.  It ensures every fastener they produce is of maximum strength and quality.  Contrary to many people’s assumptions a bigHead resistance weld is also the strongest part of the fastener and is actually a point of strength and not of weakness.  Indeed, one of bigHead’s pass/fail criterion for the tensile load test carried out on each lot is that the weld does not fail before the steel itself.

All metal Lock-Nut version

Following requests from many of our clients we have been working on a new design of bigHead that can offer the facility of locking the fixing screw into a bigHead fastener. The result, as you can see below is the first of it's type and another addition to the ever expanding bigHead range. The part shown has been designed around our flagship head size (the B38 round), and utilises an all metal locking nut for added strength and security.
If you are interested in this or any other products in our range, don't hesitate to call us; our contact details are available via the "contact us" link on the home page.

New fastener for bonding to steel plates

bigHead has recently developed a solid head fastener for a customer to surface bond to steel to avoid the fire risks of welding on site. Important to the customer was the enclosure of the adhesive within the head of the fastener, as well as the convenience of installation and the final strength.  We came up with a way to instantly fix the fastener in position with a sticky pad while the high strength adhesive cures over 24 hours.  In load testing the adhesive bond failed at over 2KN in tensile and over 9KN in shear.  Take a look at the photos below and let us know what you think.