Lag screws are traditionally specified for many structural loads in wood construction. However, recent innovations in engineering for self-tapping wood screws have made them an increasingly popular, labor-saving alternative to lag screws. In the following post, Aram Khachadourian, P.E., of Simpson Strong-Tie discusses the structural and economic advantages of this option.
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Tag: self-tapping screws
Wings or No Wings?
While the title of this blog post might remind you of the tasty turkey dinner you enjoyed on Thanksgiving, it’s actually a question regarding a shear wall component’s effect on performance. What type of fastener do you use to attach wood structural panel sheathing to cold-formed steel (CFS) framing, and what is the effect on a shear wall assembly?
Structural sheathing is most commonly attached to CFS framing with self-piercing or self-drilling tapping screws, power driven pins, and adhesives.
The AISI North American Standard for Cold-Formed Steel Framing – Lateral Design standard (S213) specifies using either #8 or #10 self-tapping screws (depending on the assembly) that comply with ASTM C1513, and have a minimum head diameter of 0.285” or 0.333”, respectively.
It’s worth noting that you cannot verify ASTM C1513 compliance by simple inspection. While screw dimensions are easy to measure, other features such as hardness, ductility, torsional strength, drill drive, and thread tapping cannot be evaluated in the field or by visual inspection. It’s prudent that a Designer and jurisdiction expect a screw manufacturer to validate its product’s compliance with ASTM C1513. This can be done through test reports by an accredited test lab and evaluation data, or by an evaluation report published by an ANSI-accredited product certification entity such as ICC-ES or IAPMO UES.Continue Reading
