The Simpson High-Strength Coupler Nut with Witness Hole is engineered to connect threaded rods to one another and to anchor bolts, delivering a structurally reliable joint in demanding applications. Designed to exceed the specified minimum tensile capacity of the corresponding bolts and threaded rod, this high-strength coupler nut gives installers confidence that every connection meets load requirements. The built-in Witness hole provides a straightforward visual check that both rods are fully seated, while the positive stop keeps thread engagement consistent from each end - eliminating guesswork and supporting repeatable, code-worthy results.

Key Features

• Witness hole verification - tighten the two rods until each all-thread rod is visible in the Witness hole, giving installers a clear, on-the-spot confirmation that both rods are properly and fully engaged before moving on.
• Positive stop feature - helps ensure proper thread engagement into each end of the nut, preventing one rod from threading too far through and keeping the connection balanced and secure.
• Exceeds minimum tensile capacity - designed to surpass the specified minimum tensile capacity of the corresponding bolts and threaded rod, so the coupler nut is never the weak link in the assembly.
• For non-hot-dip galvanized all-thread rod only - specifying the correct rod type from the start protects thread fit and connection integrity; for hot-dip galvanized applications, see the OST models with oversized threads.
• 3/4 in. rod diameter, 2 in. minimum height - sized to pair precisely with 3/4 in. all-thread rod, providing adequate thread engagement depth for high-strength structural use.

Why This Product

• Built-in quality assurance on every install - the Witness hole turns rod seating verification into a simple visual step rather than an assumption, reducing the risk of under-engaged connections in structural or anchoring applications.
• Strength you can count on - because these coupler nuts are designed to exceed the specified minimum tensile capacity of the corresponding bolts and threaded rod, the connection point holds up to the same demands as the rod itself.
• Consistent results across a crew - the positive stop feature removes variability from threading by ensuring even engagement into each end of the nut, making proper installation straightforward regardless of who is on the job.
• Made in the United States by Simpson - manufactured domestically to Simpson quality standards, this coupler nut is a dependable choice for contractors and engineers who need confidence in every component of a threaded rod assembly.

Specifications

• MPN: HSCNW3/4
• Brand: Simpson Strong-Tie
• Rod Diameter: 3/4 in.
• Height (min.): 2 in.
• Coating: Zinc Plated or Uncoated
• Finish: Zinc Plated or Uncoated
• Country of Origin: United States

Options

• Available in standard strength and high strength depending on corresponding rod in use
• Couplers available with oversized threads on one end for installation on hot-dip galvanized bolts (See OST models for ordering)
• OST couplers are typically oversized on one end of the coupler nut only and will be marked with an "O" on oversized side

Frequently Asked Questions

What is the purpose of the Witness hole in the HSCNW3/4 coupler nut?

The Witness hole serves as a visual verification tool. Installers tighten the two rods until each all-thread rod is visible in the Witness hole, confirming that both rods are properly and fully engaged within the coupler nut.

What does the positive stop feature do?

The positive stop feature helps ensure even, consistent thread engagement into each end of the nut. This prevents one rod from threading too far through the coupler at the expense of the other, promoting a balanced and secure connection.

Can the HSCNW3/4 be used with hot-dip galvanized all-thread rod?

No. The HSCNW3/4 is designed for use with non-hot-dip galvanized all-thread rod only. For installation on hot-dip galvanized bolts, see the OST models, which feature oversized threads on one end to accommodate the thicker galvanized coating.

How does the tensile capacity of the HSCNW3/4 compare to the rods it connects?

The HSCNW3/4 is engineered to exceed the specified minimum tensile capacity of the corresponding bolts and threaded rod, ensuring the coupler nut is not the weak link in the connected assembly.

Note: Product dimensions and/or screw or bolt holes may differ from picture. Please see item description for specifications.