We call Cam & Spring Clamping for standard quarter turn fasteners and Ball-lock Clamping for ball locking quarter turn fasteners.
Cam & Spring Clamping is clamped by the reaction force that compresses the spring. But the same spring reaction force is used to hold against external force as well, so the clamping force and holding force are the same.

Ball-lock Clamping have the same clamping mechanism. But against external force, the ball is pushed out by the wedge to hold the plates, even if the external force is greater than the clamping force. Therefore, the holding force is higher than the clamping force.

The Holding force limits the gap between plates within 0,1mm, even if the fastener receives a tensile force exceeding the clamping force.

So, if you have to select your spanclamps Fasteners according the forces needed,be careful when you see the tensile force.

The Tensile Strength  is breaking limit and is not intended for long-term use.
Holding Force should be considered for long-term use.

Please see below the explanation of difference of clamping mechanism between each fastener :

For your information, Heavy-duty Ball Locking Quarter Turn have the highest Holding Force of 2500 or 5000 N depending on the size per 1 piece.

If you have any questions, please contact us.