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Frequently Asked Questions

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The questions below are those most commonly asked about Avdel® blind fasteners and installation tools. Please contact us for further details if you can not find an answer to your question.



Fastener Grip

  1. Can I place Avdel® fasteners outside the specified grip range?
    For optimum fastener performance the grip ranges detailed on our technical data sheets should be adhered to, otherwise performance of the fastened joint will deteriorate.



Hole Preparation

  1. Is hole size important?
    Yes. Hole sizes should be taken from the relevant fastener technical data sheet. This is particularly important for Avdel® Speed Fasteners where different installation tooling can be used according to hole size.

  2. The hole I have is too large for the specifications given for the fastener. What can I do?
    The next fastener size "up" may be suitable or a tooling change may help. You should contact your local Avdel® representative to discuss your application in detail.

  3. Can fasteners be used in slotted holes? Ob-round holes for example.
    Yes but we strongly recommend the particular application is tested to establish if the hole type has affected the fastener performance.

  4. Does a hole have to be square to the surface?
    Yes if you want to ensure correct fastener performance. Shear and tensile strength can be greatly affected by misaligned holes.

  5. Do burrs on holes affect the fastened joint?
    Yes, burrs cause many problems including incorrect/poor installation and seating of the fastener. Burrs can also separate joint surfaces unknowingly. Burr-free holes should always be used.



Thermal Concerns

  1. Will fasteners relax with repeated heat cycling?
    All fasteners will relax slightly over time. Rivscrew® fasteners in particular are excellent in dealing with severe heat cycling as found in power supplies or motor controls.

  2. Will a solder bath affect fastener performance?
    Not to any noticeable degree because the high temperature duration is short.



Surface Finishes

  1. Do Avdel® products meet the RoHS Directive?
    Yes. In conjunction with metal finishing companies, the automotive industry, and the electronics industry, Avdel® has developed finishes that are free from both hexavalent chromium (Cr6+) and lead. All Avdel® products with zinc and zinc alloy plating receive passivation treatment containing only trivalent chromium (Cr3+).

  2. Can plating be a problem inside holes?
    Yes, heavy plating will reduce hole sizes and increase grip. Processes such as "galv dipping" can block even large holes. We strongly recommend that processes affecting hole condition are always checked for changes in fastener installation and joint performance.

  3. Do finishes such as paint, powder coating or stove enamel affect electrical conductivity between the fastener and joint material?
    Yes, these finishes may insulate the fastener from the joint material, unless breakthrough features are used such as splined fasteners.

  4. Do finishes such as paint, powder coating or stove enamel on the joint material affect fastener installation and performance?
    These finishes may increase the thickness of the joint material, which in turn can cause the fastener to be outside its specified grip range. We strongly recommend these finishes are taken into account when specifying the fastener for the joint.

  5. Many Avdel® fasteners are made of aluminium which is a known contaminant of solder baths. How do you overcome this problem?
    Whilst aluminium is not ideal in this situation, the surface area of the head is so small that in practice no problems are actually experienced. If aluminium is not permitted at all then most of our fasteners are available in plain brass or hot tin dipped brass which is ideal for soldering.

  6. Do you manufacture any fasteners with insulating properties?
    No. Owing to the manufacturing process, insulating coatings are not practical. Speed fasteners such as Briv®, Chobert® and Rivscrew® work very effectively in conjunction with plastic insulating pillars, washers and sil pads etc to produce an insulated joint.



Speed Fastening

  1. I want to use Briv® fasteners on my production line but there is not enough time to reload the paper pods. What can you suggest?
    Many Briv® fasteners can be supplied as pre-loaded "cartridges" which eliminates the time and need to load the fasteners onto the mandrel and strip off the paper. To further reduce reload time, "rapid reload" versions of the 753 series installation tool are available. Please contact us for details.

  2. With regards speed fasteners, how do you produce a consistent clamp load without torque control?
    The design of Avdel® speed fasteners and tooling allows us to engineer and control the installation process to reproduce a highly consistent joint.This removes the calibration issues of drivers etc for screws.

  3. What is the smallest electronics speed fastener?
    The smallest diameter is 1/16" (1.60mm) (Avlug® stand off pillar), for a recommended hole size of 1.8/1.9mm.

  4. How many fasteners do you get in a pod?
    This depends on the body length of the fastener. The longer the fastener, the less there are in one standard pod. Pods contain from 15 to 60 speed fasteners.

  5. How much is the rear side tail protrusion of a speed fastener?
    Briv® fasteners and most of the other speed fasteners will have around 0.8-2.0mm. This saves space on PCB's and allows greater rear side clearance compared to conventional hardware.

  6. Can we place speed fasteners on to a populated surface mounted PCB prior to reflow?
    Yes. The placing method is smooth and without torque or shock on the hydro-pneumatic tools, therefore the chance of dislodging surface mount components is very small. The fasteners are also unaffected by reflow.

  7. How do you remove speed fasteners from a PCB or chassis?
    The residual hole/bore through the centre of each speed fastener provides a nice easy pilot hole for a drill. Select a drill with the nominal hole size to match the hole in your host materials.

  8. Are different surface finishes available?
    Yes, for instance hot tinned dipped finishes for ease of soldering and yellow passivation for increased corrosion resistance. A variety of other finishes are available, please contact us to discuss your requirements.

  9. Which fastener will give clamp in an electronics joint, for example a PCB and component?
    All Avdel® speed fasteners produce clamp in a joint but Briv® and Rivscrew® fasteners will give the best result in applications requiring high clamp, providing that all recommendations for these products are followed.

  10. Will Rivscrew® fasteners effectively hold components to PCB's and be removable?
    Yes Rivscrew® fasteners has been successfully used for many applications requiring components to be secured to PCB's, including heat transfer and earthing applications. Thier removabilty and reusability have been proven in numerous PCB applications.

  11. Are Rivscrew® fasteners effective in different materials?
    Rivscrew® fasteners can be used in a variety of materials, including PCB's, plastics, aluminium and various alloys such as zinc and magnesium. It is limited by the parent material hardness which must not exceed 105Hv5 (Vickers hardness value), and therefore applications must be tested to ensure correct function of the fastener.

  12. Will Rivscrew® work in a through soldered PCB?
    Rivscrew® fasteners work very well in through soldered holes. Whilst a thread is created in the through solder, break-through is not normally a problem due to the malleable properties of solder and the way in which Rivscrew® fasteners work.



Threaded Inserts

  1. Why does my threaded insert turn in the sheet?
    This often occurs when the insert has been under placed due to incorrect setting of the tool stroke length. An oversize hole in the application may also be the cause.



Tooling

  1. Why does it take two pulls of a tool to install Avdel® fasteners?
    If the installation tool is a Avdel® tool, this is often due to neglect in priming the tool with oil. Priming procedures and tool servicing are detailed in the relevant tool manuals. If the tool is not a Avdel® tool, it may be a universal tool which has not been specifically designed to install Avdel® fasteners.

  2. Can Avdel® fasteners be placed with your competitor's tools?
    Yes, however as these tools are not specifically designed to install Avdel® fasteners, the performance of the fastener may be affected. We strongly recommend the fastener is tested in the application to determine exact performance levels.

  3. I want to use fasteners for repairs outside where there is no air supply. What tools can I use?
    Hand tools can be used for low volume requirements. For larger volumes of breakstem fasteners the TX2000® battery powered tool is suitable.

  4. What is the best tool to install speed fasteners on a PCB?
    The 753 hydro-pneumatic hand held tool or the 7475 hydro-pneumatic bench-mounted tool are the most suitable because their soft action will not apply severe shock loads to a populated PCB.



Water Resistance

  1. Are Avdel® fasteners water resistant?
    Certain ranges of Avdel® fasteners are weather resistant, including Avdel® SR sealed fasteners, Monobolt® and Avtainer® fasteners. However, the application could for instance leak water around the outside of the fastener. We strongly recommend that the fastener is tested in the application to determine sufficient performance levels.