To eliminate metal fatigue and breakage during conventional lifting operations, repeated fatigue tests resembling actual lifting operations have been conducted at the National Research Institute for Metal Materials. This model withstood 2,650,000 repetitions of the test, demonstrating that the clamp has a long lift. Furthermore annealing and other treatments to repair fatigue damage are not needs.
  1) Special alloy steel is used, and as a precision drop forged, heat treated product, resistance
      against fatigue is greatly improved.
  2) Since it is drop forged, it is lightweight.
  3) Models DL-B and DL-B/B have wire latches.