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Clevtec

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In  2008 when the world stopped due to the financial crash, we had to re-evaluate our business model as we realised that if people didn’t want the fasteners we manufactured at Clevedon, we were pretty much sunk. As a result we created Clevtec. Clevtec is a trading arm of Clevedon Fasteners Ltd and unlike Clevedon who are a purely a manufacturing entity, Clevtec is able to buy and sell product all over the world, as long as it made a return. This meant that as well as fasteners, Clevtec could venture into other parts of the fastener market, that we were unable to make at Clevedon.

Clevtec soon found that there was a latent demand of high quality threaded fasteners, particularly if they were of UK origin and so in 2012 we purchased a company called Blakeacre who specialised in high quality threaded fasteners and they became part of Clevtec. In addition to threaded fasteners, Clevtec over the years has got into Commercial Vehicle brake shoe platforms and various types of setting machines, the latest of which being spin riveters.

Clevtec’s latest market offering is a range of services that we believe our existing an new customers will find of interest. Over the past year we have been developing with a selected number of existing customers, two specific services:

 

Supplier reduction service

Design Support service

We are now in a position where we are able to offer these services to other customers. The details of these services will be on our new Clevtec Services web site and will be the subject of further Blogs in the future

Clevtec Services  https://www.clevtecservices.co.uk/

Contact us on 0121-378-5967

or email me on steve@clevtec.com

Designed to Fail

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In this age of high tech, computer based design. A growing problem is becoming obvious to us here at Clevedon. As you know, whilst we do some very clever cold forgings and self-piercing products, our main business is based on the humble rivet. Solid Semi-Tubular and Fully tubular rivets. Some of you reading this blog may not even know what these products are or will confuse them with “pop” or other blind rivets

Therein lies one of the problems with modern design techniques. A confluence of two factors, demise of “old style” apprenticeship’s where some of our best engineering talent learned their trade and the rise of the computer savvy, iPad literate younger generation, many young designers have not been taught some of the most basic, fundamental engineering techniques.

This is not their fault, most CAD systems are great at producing designs drawings. Unfortunately, only certain techniques are included in the various wizards and “look ups” which mean that only certain outcomes will be produced.

Quite often these unintentionally, pre-defined outcomes are very difficult to productionise and more importantly very costly to manufacture.

We have had experience of being told by very well meaning designers that our suggested fixing proposal will not work because their Finite Element Analysis (FEA)testing show that the rivet will fail at a particular load. This despite that fact that in our long history (we began business in 1939), we have never encountered a failure mode of the type the FEA predicted would happen. To prove the point, we undertook practical testing to discover what happens in actual practice. The rivet did not fail.

Drawings are sent to us where in order to realise the designers dream, the product needs to be turned, milled, drilled, ground etc.  Each operation results in expensive individual set up and run times and thereby the final product is very costly to manufacture, at which point some very innovative designs are dropped because they do not make economic sense to peruse.

Powder printed samples are very good straight off the CAD system, but are incapable of predicting that the whole project will fail due to the lack of basic engineering input at the beginning. The old adage rubbish in, rubbish out, still holds true. All of these very sophisticated, technologically advanced  CAD and FEA systems all have the same fundamental, inherent weaknesses and results in the waste of large amounts of time, money and company resources, to say nothing of the potentially game changing design concepts that never come to fruition.

Here at Clevedon (the parent of Clevtec) we do not claim to have all the answers, but we are very good basic engineers. Having had to fight against overseas competition that has destroyed many good UK engineering companies we do have a very good track record in providing low cost, practical, innovative solutions to seemingly intractable design issues.

For the above reasons we have introduced a “Design Support Agreement” to work with designers to put some of the practical elements back into the design process that don’t come straight out of the can. We have found this has the most beneficial effect when we are involved early on in the design cycle but have also been able to re-engineer designs that have got into difficulty (usually cost difficulties).

Please contact us and ask for Steve Hardeman and we will very soon be able to let you know if we are able to help.

PT Screws

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Screw3

The growth in the use of PT 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. PT 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 PT screws manufactured at our two plants in Birmingham UK, currently cover 2.2mm up to and including 6mm diameter PT Screws in metric and imperial sizes (including Tri-lobe).

There are so many versions of PT 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

Screw1

 

Testing, Setting, Heat Treatment and other News

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As you know, we manufacture Clinch StudsCD StudsWeld boltsBolt Loks™ etc. at our Great Barr plant in Birmingham UK. Like any manufacturer we take care to ensure the quality of our products, ensuring that every product is fully traceable from the base material through forging, thread rolling, heat treatment, plating, and dispatch. At Clevtec we try to go the extra mile. Our testing facilities enable us to ensure the performance of our products meets and in many cases exceeds industry norms.

clinch stud

clutch leaflet

Not working, could be your fault! What many of our customers don’t know is that the performance of the product is often compromised by the way it is set. Many products are set to a torque requirement, particularly in automotive

applications.

Many products are set to a torque requirement, particularly in automotive applications.

Did you know the torque performance could be reduced by 25% if the threads have any oil on them?

self_clinching_studs_stainless_steel

 

 

Don’t compromise on heat treatment

Many products are specified by customers to property class 8.8.

For those of you who are technically inclined, (ref. ISO898 Pt-1).

However, We heat treat our products to 10.9 property class unless specifically requested by the customer.

The reason for this is that 8.8 is on the cusp of needing to be de-embrittled. 320 VPN is the cut off point for products to be de-embrittled (250/320VPN below 16mm diameter).

To avoid any compromise regarding the quality of our products, we choose to heat-treat our products to property class 10.9 because at this level, hydrogen de-embrittlement is mandatory.

10.9 out performs 8.8 mechanically so the influence of lubricated nuts etc. is less significant. More importantly, in the unlikely event of a failure, hydrogen embrittlement cannot be to blame.

studs1SCS_FH


In other News………

The zinc and yellow passivation to be outlawed next year!

We are still asked to produce parts which are Zinc and yellow passivated. Some customers insist on this and will not take the zinc and clear passivation option. Yellow passivation will be outlawed in September 2017, there is some discussion around the certainty of this date but if a chemical supplier can develop a viable economic alternative with the same apparent colour (first across the line wins!)  Then the date will hold

Brake lining rivets and the American Clean Water Act

We produce copper brake lining rivets. These may be outlawed in 2021 as a result of the American Clean Water Act. An element of this act was specifically included in order to reduce urban runoff into San Francisco Bay. It has been estimated that 35/60% of urban runoff comes from brake shoes. The obvious answer is to change to steel brake lining rivets that are plated. The problem is that brake linings from countries that do not have rivet setting technology set the rivets by hand (not to be recommended, but it happens). The time line varies from state to state but manufactures are going for 2021. So what? I hear you say. Many environmental laws made in the US migrate to affect Europe; it’s as well to be aware