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Learn more about Hilti's reliable decking solution

Hilti HSN 24 decking application
Hilti’s mechanical fastening system portfolio for attaching steel deck to bar joist or structural steel provides an innovative, consistent, and reliable solution. There are many advantages of mechanical fasteners over the conventional arc spot puddle weld attachment method. Review the reference links below to further understand the advantages of Hilti’s mechanical fasteners and the limitations of puddle welding.

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Inconsistency with puddle welds

Recent research by Virginia Tech colleagues Gregory L. Snow and W. Samuel Easterling found that arc time has a tremendous effect on weld strength (as referenced in the graph). Their research shows that proper arc spot welding of steel deck takes an average of 8.1 seconds per weld for a 5/8 in. arc spot puddle weld and 12.8 seconds per weld for a ¾ in arc spot puddle weld. A lack of consistency with puddle welding in the field could result in significant load reductions.

Virginia Tech Weld Study Report

Inspection Quality

In reference to a typical weld inspection, an inspector in Vancouver said, “[I] check the puddle size. Not really anything else you can do.” The same inspector’s response to mechanical fastening inspection, “[I] check to see that the pins were installed into the steel below. Pins are better because they are verifiable!” Because the weld diameter is a visual inspection, welders may turn up the amperage on their tool to achieve the “proper” size without also ensuring proper fusion. Mechanical fasteners do not allow for this manual alteration.
A flowering of the top hat seen from top and side views indicates A flowering of the top hat seen from top and side views indicates "proper standoff".

Working Principles of Hilti Mechanical Fasteners

With Hilti mechanical fastening pins, there is the working benefit of a weld, a screw fastener, and a pin. All four principles depicted at right work together to optimize the loading capacities of the pin. Friction, mechanical interlock, soldering or brazing, and fusion are all achieved and result in superior performance in shear and uplift. Resulting capacity of Hilti decking fasteners typically meet and often exceed the capacities of welds.

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Research indicates that welded steel deck performs poorly under cyclic loading. Typical puddle welds do not allow for load redistribution and are not able to sustain excessive deformations without fracture.

Hilti mechanical fasteners were shown to outperform with respect to cyclic inelastic behavior under cyclic loading. The videos below comparing mechanical fasteners to welds were taken from the Hilti Fastening Systems Research Laboratory (FSRL), which allows for full-element testing and extensive R&D.

Reference Articles: "Inelastic Seismic Response of Frame Fasteners for Steel Roof Decks"

Consistency, Reliability & Productivity

Three words that are important for any designer or installer—consistency, reliability, and productivity. By including Hilti mechanical fasteners in your design, you can achieve all three.

The unique, top hat design of Hilti fasteners helps clamp the deck and allows for a wide range of penetration while achieving a proper fastening. This increases the quality of fastening from pin to pin.

The easy-to-use tool that drives the mechanical fastener has an adjustable power regulator . The piston technology pushes the fastener into the base steel and helps prevent the pin from being over driven.