Troubleshooting Guide

Problem: Unnecessary clamp breakage.

Solution: Our 38 years of experience tells us that a customer who is breaking Duraclamps is either over tightening the clamps with a tool or hitting the clamps on the side of a tank. The Duraclamps are designed to be tightened to a torque of 50 to 60 inch pounds by hand or by our factory set Duralok™ torque wrenches only. This range is more than adequate to properly secure extrusions. We have been very successful in the United States with the few customers who have a problem, by taking a torque tester to their facility and checking loads. You will usually discover that potential problem clamps are torqued to 150 inch pounds with some type of "handmade" tool.

Our "Quality Control Procedures" are quite extensive. We test 10% of the total clamps we produce to a torque that is almost three times the torque that hand tightening can produce. For example, the 476 and 476T clamps are tested to 135 in. lbs. The Duraclamp holds the highest torque of any clamp on the market. We've tested every competitor that we've been able to get samples from.

We have also had success with customers in the United States who are trying to rack heavy extrusions with small clamps by switching them to the 390 or 508 Duraclamp. These clamps have even thicker frames and are priced quite fairly.

Problem: A pattern of small bubbles is seen in the center of a clamp frame after it has been broken.

Solution: The bubbles are produced by the introduction of a small percentage of blowing agent during the injection molding process. The foaming agent is necessary and beneficial to the design of the thick cross section found in the clamp frame. The foaming agent actually reduces the residual stress in the clamp and produces a part with more available strength. We have tested clamps produced without foaming agent numerous times and they are actually weaker than those produced with the agent. Our engineers designed the Duraclamp frame to provide maximum strength and eliminate dragout.

Problem: Clamps bind between frame and screw and begin to lose their shape.

Solution: The Duraclamp plastic resin is rated to 212º F or 100º C. Clamps that are exposed to higher temperatures for long periods of time will begin to soften and lose their structural integrity. Up to 250º F the distortion won't be visibly noticeable, however, thread binding can occur and the clamps become unusable.

Problem: Clamps become discolored.

Solution: The Duraclamp can take on a greenish/yellowish color if exposed for numerous cycles to the chemicals found in a brite dip bath. The discoloration caused by phosphoric acid and brite dipping should have no effect on the performance of the Duraclamp.

Problem: Cracks or fissures appear in the clamp frame section that surrounds the screw.

Solution: This is normally caused by improper alignment between the screw portion of the clamp and the part that it is securing. The ideal positioning of the screw is 90 degrees or at a right angle from the part or extrusion. Screw misalignment will place undue stresses on the frame and reduce load carrying capacities. Also, if the load is extremely heavy, let the rack support the load and use the Duraclamp for a positive electrical connection. This can be accomplished by welding short cross pieces on your existing spline bar.


DuraclampProudly serving the Metal Finishing industry for more than 40 years.

Quality products made in the USA.

Duraclamp is manufactured by Burlingham International. Be sure to view the other quality products that we offer.

contact us

Burlingham International
1041 W. 18th Street, A-109
Costa Mesa, California 92627 USA 
1 (800) 659 5506 (USA Toll Free) 
+1 (949) 645 1529 (International) info@duraclamp.com

Find us on Facebook Duraclamp on Facebook