Hollo Bolt ®, the expansion bolt made by Lindapter International for use with hollow structural steel sections, has earned the stringent approval of a City of Los Angeles Research Report. The LARR decision was based on Hollo-Bolt® gaining full seismic approval from ICC-ES in Evaluation Report ESR-3330, paving the way for it to be implemented in the construction of the Wilshire Grand Center in Downtown LA which will become the tallest building in Los Angeles and the tallest building west of the Mississippi River upon completion.
More than 3,000 Hollo-Bolts were used to fasten the steel tubes that comprise the Wilshire Grand’s curved atrium. No drilling or welding was necessary to make the connections, achieving a look that is more aesthetically pleasing while greatly reducing cost, project time, and job site safety hazards.
Hollo-Bolt® is a three-part fastener designed specifically for connecting square, rectangular, or round HSS members and are identified for resisting static tension and shear loads in bearing-type structural steel connections.
These innovative structural connections can be easily installed from only one side in situations where access is limited. A five-part “High Clamping Force (HCF)” model which features a patented HCF mechanism to produce three times more clamping force is also available in M16 (5/8”) & M20 (3/4”) sizes. The Hollo-Bolt® may be used to resist wind loads and is cleared for use in all ICC Evaluation Service (ICC-ES) seismic design categories from A through F, the only structural blind connection fastener to earn such distinction.
Hollo-Bolt’s LARR approval and subsequent inclusion in the 73-story Wilshire Grand skyscraper is not merely a validation of the fastener’s merits in California, as these developments have the potential to affect building design and construction considerations on a national stage.