The Simpson CNW1/2 Coupler Nut with Witness Hole is a Simpson engineered fastener built to connect threaded rods to one another and to anchor bolts in structural applications. Designed to exceed the specified minimum tensile capacity of the corresponding bolts and threaded rod, this 1/2 in. coupler nut delivers the load-bearing confidence required in rod connection systems. A built-in Witness hole and a positive stop feature work together to take the guesswork out of proper installation, making the CNW1/2 a dependable choice for contractors and builders who need a verified, secure threaded rod splice.

Key Features

• Witness hole for installation verification - tighten the two rods until each all-thread rod is visible in the Witness hole, giving you a clear visual confirmation that rods are properly installed and fully engaged on both sides of the nut.
• Positive stop feature - helps ensure proper thread engagement into each end of the nut, so the connection is balanced and consistent without relying on guesswork or feel alone.
• Exceeds specified minimum tensile capacity - designed to surpass the tensile requirements of the corresponding bolts and threaded rod, supporting the structural integrity of the overall rod connection.
• Compatible with non-hot-dip galvanized all-thread rod only - knowing the correct rod type upfront prevents mismatched installations and keeps your connection performing as engineered.
• 1/2 in. rod diameter with a minimum height of 1 1/4 in. - purpose-sized dimensions ensure a consistent fit for standard 1/2 in. threaded rod and anchor bolt applications.

Why This Product

• Built-in verification takes the uncertainty out of rod splicing - the Witness hole gives installers a tangible, visual check that both sides of the threaded rod connection have reached proper depth, reducing the risk of under-engaged threads in the field.
• Engineered to meet and exceed tensile demands - because the CNW1/2 is designed to exceed the specified minimum tensile capacity of the corresponding bolts and threaded rod, it supports the full strength of the rod system rather than becoming the weak point in the connection.
• The positive stop promotes consistent, repeatable installations - by helping ensure even threading into each end of the nut, this feature supports uniform thread engagement across multiple connections on the same job, reducing variability between installers.
• Trusted Simpson engineering for structural rod connections - backed by Simpson Strong-Tie design standards, the CNW coupler nut is a purpose-built fastener for connecting threaded rods and anchor bolts, not a generic hardware solution adapted to a structural role.

Specifications

• Manufacturer: Simpson Strong-Tie
• MPN: CNW1/2
• Rod Diameter: 1/2 in.
• Height (min.): 1-1/4 in.
• Coating / Finish: Zinc Plated or Uncoated
• Compatible Rod Type: Non-hot-dip galvanized all-thread rod only

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 CNW1/2 coupler nut?

The Witness hole serves as a means to verify when rods are properly installed. You tighten the two rods until each all-thread rod is visible through the Witness hole, confirming correct thread engagement on both sides of the nut.

What does the positive stop feature do?

The positive stop feature helps ensure even threading into each end of the nut, promoting balanced and proper thread engagement from both sides of the connection.

Can the CNW1/2 be used with hot-dip galvanized all-thread rod?

No. The CNW1/2 is designed for non-hot-dip galvanized all-thread rod only. For use with hot-dip galvanized bolts, Simpson Strong-Tie offers OST models that feature oversized threads on one end.

What are the key dimensions of the CNW1/2 coupler nut?

The CNW1/2 is designed for a rod diameter of 1/2 in. and has a minimum height of 1-1/4 in. It is available in a Zinc Plated or Uncoated finish.

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