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Our New Optical Sorting Machine

We are delighted to announce we have recently taken in delivery of a latest, state of-the-art sorting machine!

This is our most advanced optical sorter – having four cameras and an Eddy current checking station which can be used for comparative testing; ensuring parts are to the correct heat treatment specification (Property class).

As our sales of threaded parts in general continue to increase, with clinch studs in particular, we wanted to provide customers with a greater level of security regarding the products property class – rather than simply supplying a second-party heat treatment certificate.

The cameras not only check for contamination and dimensional inaccuracies, but also incorrect aesthetic elements such as misshapen heads, clinch ring defects, and colour. As well as lettering and other non-dimensional problems.

The parts which pass the camera and Eddy current scrutiny are fed directly into the dispatch boxes ready for shipment to the customer. This ensures no post-sort contamination. The combination of these technologies ensure we move nearer to our goal of defect-free products, and to build upon our already impressive quality record.

Cold Forging Basics

Riveting is one of the oldest forms of fastening.

Solid rivets have been found dating back to the Bronze Age (ended 800BC)

You will have seen rivets hidden in plain site on bridges, ships, Aircraft and Trucks to name a few common applications.

They are also common throughout your home, if you have double glazing then you will probably have our rivets in the hinges.

Rivets are formed by a process called Cold Forging, this process produces no waste as the head of the rivet is formed by upsetting the shank of the rivet. This ensures the grain flow of the material remains in-tact thus strengthening the fastener.

The rivets are inserted in the material to be fixed together and “set” by deforming the end of the shank of the rivet to product a permanent fix.

The more popular, semi-tubular rivet is set in a similar way but require a lot less setting load and provides a “Clinch” fix which pre-stresses the material.

Many engineers are unaware of the advantages or even the function of rivets, tending instead to fall back on threaded fasteners which are more widely available.

The most recent development in Riveting is the self-piercing rivet, where you do not need a hole in order to rivet two materials together. This process is now commonplace in state-of-the-art automotive manufacturing plants. JLR being pre-eminent in this regard.

The process used to produce these fasteners has been developed in order to use the same manufacturing technique, Cold Forging, but to enable finished components to be forged outright, with the same benefits, no waste and a very strong structural integrity.

We are happy to help customers or prospective customers with any queries that may have regarding riveting or cold forging. We have recently helped a number of companies by producing and riveting prototype designs for them.

We have been in this business since 1939, over that time we have provided innovative, low cost solutions to many fastening and cost reduction requirements, thrown at us by our customers.

In the first instance, contact me, Steve Hardeman either by e-mail ( ) or by telephone on +44(0)121-378-0619

Plastic Thread Forming Screws


The growth in the use of Plastic Thread Forming Screws is driven in part by the need to reduce the total weight of an increasing number of component assemblies, either new design or redesign.

The type of plastic selected for the required component performance means that it is essential to use a fastener that maximises clench properties by ensuring high strip out torque values and in many applications prevents loosening due to vibration. Plastic Thread Forming Screws are the ideal fastener for such applications where fasteners such as self-tapping screws for steel applications would fail due to their wide flank angles and shallow threads

Clevtec’s ever increasing range of Plastic Thread Forming Screws manufactured at our two plants in Birmingham UK, currently cover 2.2mm up to and including 6mm diameter Plastic Thread Forming Screws in metric and imperial sizes (including Tri-lobe).

There are so many versions of Plastic Thread Forming Screws available, we tend to manufacture to customers specific requirements

Ideally we would like a fully detailed drawing of what you require together with some idea of  the volumes you will be ordering

In the absence of a drawing, we need to know the thread size and type (Imperial or Metric), what type of head you require, Pan Head, Pan Flange, Countersunk, Mushroom etc. Do the heads need to be marked? what type of drive do you require for the screw, we can do manufacture most standard forms in common use

The trickiest area in the absence of a detailed drawing is heat treatment and finish. again there are many different requirements that can trip up the unwary. Is the product property class 10.9 or is it a through harden/case harden treatment? All our heat-treated parts that require zinc plating  (the most common finish) are hydrogen de-embrittled. The de-embrittling time can vary depending upon the heat treatment hardness that is specified

If you need any advice please call us


CL2B Rivet Setting machine/Pneumatic press £1,199

The CL2B full details of this machine can be found at–riveter

The machine is bench mounted and designed for low volume manufacturing, it simply requires an air supply and so is ideal for small scale manufacturing (prototypes etc.) but is primarily designed for low volume commercial vehicle re-lining operation as the tools it comes with are capable of setting up to 8mm diameter semi or fully tubular rivets (The full range we manufacture can be found at together with a links showing the relevant dimensions)

We would be more than happy to discuss this machine and its capabilities by contacting us at or ring us on +44(0)121-378-5960

Alternatively, we do sell this product through e-bay

As the machine only needs an air connection it can be used world wide, special prices available for quantities of 5 off or 10 off please contact us to discuss your specific requirements

PR-5 battery powered self-piercing rivet machine

We are pleased to offer the PR-5 battery powered self-piercing rivet setting machine. We have added this machine to our range specifically to help our sheet metal and HVAC customers. We feel it will also be of interest to vehicle body shop customers as vehicle bodies are increasingly assembled using Self Piercing rivets.

The PR5-5 can also be used to set semi-tubular, full tubular and solid rivets as well as having rivet extraction capabilities


Because of our long experience in self-piercing and the fact that to many SME’s it is an unknown quantity, the product is only sold after we have proved its capability to potential customers by riveting the application that they have in mind to their total satisfaction

The rivet specification is key to the joint performance when the rivet is set and so the machine will only be sold only when we have set and tested the rivet joint to the customer’s satisfaction, this also acts as a training platform for those unfamiliar with the technology to ensure its correct operation in the field

It is vitally important that the correct rivet is used to ensure a secure joint. Changes in material thickness will affect the performance of the joint. Any changes of this type should always be discussed with us prior to implementation as a different rivet configuration may be required

As well as the machine and tooling the PR-5 comes complete with two rechargeable 18V batteries together with a 240/110 V charger for continuous operation of the unit

Customers interested in purchasing the PR-5 should send samples of the material they intend to rivet together and any associated drawings (to ensure access for the frame of the machine), we will then

To find out more information please go to:-

Where you will find a video of the machine in action

What do you mean,it doesn’t need a hole?


Self Piercing Rivets

Self piercing rivets can trace their ancestry back to the humble Bifurcated Rivet ( developed by the Bifurcated and Tubular Rivet Company (B&TR). A bifurcated rivet was designed to firmly fix wood together (packing cases being a good example). It works by the rivet being pushed into the two layers of wood, due to is slot angle, when it reaches the second piece, the rivet flares, causing the joint to clinch firmly, much stronger than nails and much quicker than screws.

Someone at B&TR (the argument as to who is lost in the mists of time) thought, what if we could do that with a semi tubular rivet (, productivity could be increased remarkably as there would be no reason to pre-drill the holes when fixing together sheet metal. The Self Piercing Rivet (SPR) was born (

SPR’s can fix multiple layers of sheet, even dissimilar materials without a hole (therefore no danger of water ingress) plated or painted sheets can be riveted together as the SPR setting process creates no heat (unlike conventional spot welding therefore there is no residual spatter) and so SPR riveting is an environmentally friendly process.


The benefits are obvious, no preparatory holes to be drilled, environmentally friendly, dissimilar sheets can be clinched (steel/Alum, Alum/Plastic etc.), no water ingress,

Modern setting equipment means the setting loads for each rivet can be monitored and recorded for quality control purposed

The amount of applications is rising every day, from Automotive to humble Hen House covers (yes Really!!)

If you need any further information, on these or any of our products, please contact me on 0121-378-0619 or e-mail me at





Bolt Lok™



Bolt Lok

As well as specialised cold forgings, we also make our own trademarked pin and collar fastening system Bolt Lok

This is for use when customers require a fastener with superior joining capabilities for demanding high strength assembly applications

The Clevtec Bolt-Lok™ is a quick and easy pin and collar fastening system in which the material to be fastened is permanently clamped between the pin and collar providing a high strength vibration proof fixing.

Available in Steel, Stainless steel and Aluminium and any commercially available finishes to suit customer requirements our Bolt Lok™ range includes truss, brazier and countersunk head styles. There are 12 products to choose from covering grip ranges from 1.6mm – 22.2mm.

More information can be found at

If you have any questions please contact us at

Or call us on +44 (0)121 378 5


No-one told us it couldn’t be done

The Challenge:

Cold forging an intricate drive gear


We were asked by one of our customers’ design teams to collaborate with them to produce a gear which would be stronger than their current product and less costly.


The gear in question was previously a die casting which required very expensive tooling, but more importantly, the gear was failing during their strength testing program, these repeated failures was holding up the customers proposed launch date for a new product that the gear went into


Whist we had made straight gears before, this eight tooth gear also had an involute profile to ensure constant meshing, a tough brief as in order to keep costs down, the product needed to be produced straight off the forging machine with no second operations


Our forging engineers set to work with our customers’ designers. After a couple of weeks of long days in our in- house Toolroom, we felt we had a viable tooling design.


The tooling took a further couple of weeks, manufactured in high grade hardened steel to reduce time and costs, rather than going straight to carbide, (which is what the final tooling set up would be made from). The results of the sample runs were extremely positive. After a few tweaks the product was being produced at 80 per minute off a multi- die heading machine with no second operation machining


So confident were we that the design would work, we commissioned the carbide tooling to run in parallel with customer testing. The results were encouraging, but then the customer increased the strength requirement still further, well above the original specification. This time the gear had to be strong enough that the gear casing would fail before the gear.


We achieved this by hardening and tempering the gear, finally the gear was plated to improve its aesthetic properties and grease packed at the point of assembly to ensure smooth running


Production started 12 weeks from the initial brief.


This special drive gear is just one of the specialist cold forged products in our impressive range.


Please contact us if you want advice on the viability of converting an existing product to cold forging. Or better still; involve the experts at the outset of your design project in order to get the most cost effective design results