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FAQs

Answers to your technical and commercial questions about bigHead fastening products.

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    Fastening guidance

    • Can I use a higher‑strength screw with a bigHead collar?

      To use a higher-strength screw with a bigHead collar, you must be prepared to manage the assembly tightening through careful torque and preload control. This may involve VDI 2230 based bolt-calculations, depending on your application requirements.

      Our assembly guide will help you define torque and preload limits for our collar products.

    • Can I use the torque call‑out specified for the screw?

      No. Torque tables for standardised fastening elements may not account for the bigHead collar thread loadability. Maximum recommended tightening torques for the bigHead product must take precedence.

    • Do I need to get the screw selection ‘exactly right’ for a bigHead collar?

      No. Reliable fastening with bigHead collar products does not depend on identifying a single ‘correct’ screw pairing. In most cases, there is a range of suitable screws that can be used successfully.

      Fastening performance is governed by internal thread loadability, thread engagement, and tightening control. When these factors are managed appropriately, variations in screw grade or property class are unlikely to be the determining factor in pairing compatibility with bigHead collars.

    • How can I check if the embedding or surface bonding of a bigHead will resist the screw tightening torque?

      Adhesives and embedment interfaces primarily transfer clamp load and service loads into the parent structure. Testing the rotational loading resistance of the fastener installation is not the same as determining its capability to resist torque-tightening during assembly.

      You should base any evaluation of torque-tightening resistance on assembly trials with system representative specimens, not torque-off or torque-out testing of rotational-loading specimens.

    • Is there a rule about using a lower‑grade screw than the bigHead collar?

      No. There is no property class hierarchy for screw and collar pairings. Compatibility depends on preventing internal thread overstressing through engagement and tightening control, not on screw grade alone.