Threaded Stud Pull-Test


The Challenge 

An international customer needed a unique wire rope threaded stud swaged assembly. The stud included a wrench-flat and extra long thread length, 8" of 1-1/4"-7. Essential to the design was the stud's high-performance pull-off strength, which needed to exceed 35,000 lbs installed onto 5/8" 6x19 class IWRC Bright EIPS. To ensure compliance with safety standards, each assembly needed to be proof-loaded, tagged and certified.


The Solution

Lexco made a first article assembly, which was inspected and then sacrificed during a destructive pull-test. For this test, Lexco used one of our calibrated pull-test machines. This test machine proof-loads and/or measures the breaking strength by applying pull loads. Lexco engineers are able to observe any slippage or abnormal elongation during the test. The test was documented with pictures, videos and a test certificate that included a graph of the load. The destructive pull-test can be viewed here: 

Each threaded stud included a grade 8 flat washer and hex nut. After assembly fabrication, each production assembly was proof-loaded to 14,000 lbs to assure quality and a 7,000 lbs working load limit. After proof-loading, each assembly was tagged which included assembly serialization to assist with traceability.

Prior to shipment from Lexco, the international customer confirmed the assemblies’ compliance by having an accredited third party source inspect the assemblies at Lexco. The inspector reviewed all specifications including diameters, lengths, tolerances, labeling, material certifications, and testing certifications. 


The Results

  • Lexco accommodated the customer’s source inspector.
  • Lexco met the customer's print specifications.
  • Lexco supplied a custom length threaded stud.
  • Lexco provided pull-test and proof-load documentation to ensure assembly strength.
  • Lexco’s assembly met the fit, form, and function for the customer's project. 
  • Lexco’s packaging met identification requirements. 
  • Lexco’s quality exceeded customer requirements.