FAQs

Reverse weld collar

• Are load limits for reverse weld collars the same as standard F2/SF2 collars?

  No. The reverse weld orientation creates different load paths. We can provide load-limit values and tightening torque recommendations on request to support correct application.

• How does reverse weld affect overall product length and screw engagement?

  With reverse weld collar, the overall product length is the same as the collar length. This differs from standard collar products, where overall length includes both collar length and Head thickness. Screw engagement is approximately equal to the full collar length.

• What does reverse weld collar customisation involve?

  It reorients the Head position, so that the collar shank passes through the sighted Head. The weld is applied to the flange on the shank side, instead of the Head being welded to the flange end.

• When do I need reverse weld collar customisation?

  Reverse weld collars are useful for applications where:

  • Axial fastening loads or tensile stresses may exceed the weld strength of a standard collar, or
  • You need to present a smooth, uninterrupted Head surface for component seating or moulding shut‑off.
• Which bigHead products are compatible with reverse weld collar?

  This customisation applies only to sighted internally threaded collar types (F2/SF2) and specific Head types including S20, S23, ST38A, S30, S32 and S38A, with defined thread‑size ranges for each.