The Simpson RCKWS 3-in. Kneewall Connector Stiffener is a heavy 171 mil (7 ga.) stiffener engineered to nest directly onto the RCKW clip, delivering added overturning moment resistance and stiffness when load demands exceed what the clip alone can handle. Developed by Simpson Strong-Tie, this stiffener is purpose-built for use at the base of exterior kneewalls and parapets, as well as interior partial-height walls and overhead ribbon window conditions. Its screw holes and anchor holes align precisely with those in the RCKW clip, making fastener and anchor installation straightforward and efficient. This listing includes a quantity of 10 stiffeners, and the RCKW clip is sold separately.

Key Features

• Designed for 3-5/8 in. framing with a centered single bolt hole - ensures proper alignment and secure attachment to cold-formed steel framing without modification or guesswork on the job site.
• Stiffened flanges on anchorage legs - directly improve overturning moment resistance, giving the assembly greater structural capacity in high-load kneewall and parapet applications.
• Large-diameter anchor hole sized for 1/2-in. diameter concrete screw anchors and wedge anchors - compatible with Simpson Strong-Tie Titen HD heavy-duty screw anchors and Strong-Bolt 2 wedge anchors, providing reliable anchorage to concrete substrates.
• Additional smaller-diameter anchor holes for #12 self-drilling screws - allows attachment directly to structural steel, expanding the range of substrates this stiffener can be used with on a single project.
• CMU compatibility via Titen HD or Titen Turbo concrete and masonry screws - makes this stiffener viable across concrete masonry unit applications without requiring alternate hardware or special preparation.
• Secures to the RCKW clip with screws - the screw hole and anchor hole alignment optimizes both overturning moment resistance and assembly stiffness, so installers achieve full engineered performance without custom fitting.
• G90 zinc galvanized finish - provides corrosion resistance suited to exterior kneewall and parapet environments where moisture exposure is a concern.

Why This Product

• Engineered specifically to boost capacity when the RCKW clip alone is not enough - rather than upsizing to a different connector system, the RCKWS stiffener nests directly onto the existing RCKW clip and adds overturning moment resistance exactly where it is needed, keeping the structural assembly compact and code-consistent.
• Multi-substrate anchorage in a single stiffener design - the combination of a large-diameter anchor hole for concrete anchors and smaller holes for self-drilling screws into structural steel means fewer compatibility concerns across different foundation and framing conditions on the same project.
• Heavy 7 ga. construction matches the RCKW clip for a fully rigid assembly - at 171 mil thickness, the stiffener is built to the same heavy-duty standard as the clip it supports, so there is no weak link introduced when additional capacity is required.
• Hole patterns align precisely with the RCKW clip - the matched screw and anchor hole layout eliminates the need for field drilling or repositioning, reducing installation time and the risk of misalignment at critical structural connections.

Specifications

• Model No.: RCKW3S-R10
• Width: 3 in.
• Thickness: 171 mil
• Gauge: 7 ga.
• Coating / Finish: Zinc Galvanized, G90
• Framing Size: 3-5/8 in.
• Packaging Quantity: 10
• Country of Origin: United States

Approved Applications

• Resisting overturning moment at the base of exterior kneewalls
• Resisting overturning moment at the base of parapets
• Interior partial-height walls
• Overhead ribbon window conditions
• Anchorage to concrete using 1/2-in. diameter concrete screw anchors or wedge anchors
• Anchorage to structural steel using #12 self-drilling screws
• Attachment to CMU using Titen HD or Titen Turbo concrete and masonry screw

What's Included

• 10 x Simpson Strong-Tie RCKWS 3-in. Kneewall Connector Stiffener (RCKW3S)