The Simpson MSTA21Z MSTA 21-in. 18-Gauge ZMAX Galvanized Medium Strap Tie from Simpson is engineered to resist tension loads in wood-to-wood uplift applications, delivering reliable structural performance where it matters most. Designed specifically for use on the edge of 2x members, this medium strap tie features a staggered nail pattern to help minimize wood splitting during installation. ZMAX galvanization provides extra corrosion resistance, making it a dependable choice for exterior and treated-wood applications where standard coatings may fall short.

Key Features

• Load-rated with correct thickness and number of fasteners - eliminates the guesswork and inconsistency of field-fabricated straps, giving you a connection you can count on to meet code requirements
• Loads increased for wind and seismic forces - provides enhanced structural capacity in high-stress environments, supporting safer construction in demanding conditions
• Floor-to-floor clear span application - enables continuous tension transfer between framing levels without interruption, simplifying multi-story structural connections
• Designed for use on the edge of 2x members - ensures proper fit and load transfer in the most common framing scenarios, reducing installation errors
• Staggered nail pattern - helps minimize wood splitting so the structural integrity of the wood member is preserved throughout installation
• 18-gauge steel construction - offers a strong yet workable thickness calibrated to the load ratings this strap is designed to meet
• ZMAX galvanization - provides extra corrosion resistance for exterior and treated-wood applications, extending the service life of the connection in harsh or chemically aggressive environments
• Compatible with 10d common nails or #9 x 1 1/2 in. Strong-Drive SD screws - gives installers flexibility to use widely available fasteners for a secure, code-consistent installation

Why This Product

• Engineered reliability over field fabrication - unlike a shop-bent or site-made strap, this tie is factory load-rated with the precise thickness and fastener count required, removing uncertainty from critical uplift connections
• Built for high-load structural demands - with loads increased for wind and seismic forces, this strap tie is well-suited for framing projects where connection performance under lateral and uplift loads is a primary concern
• Corrosion resistance where standard products struggle - ZMAX galvanization goes beyond standard coatings to protect the connector in exterior settings and alongside treated lumber, helping the connection remain structurally sound over time
• Installer-friendly design - the staggered nail pattern reduces the risk of splitting 2x framing members during fastening, making installation faster and cleaner without sacrificing holding strength

Specifications

• MPN: MSTA21Z
• Length: 21 in.
• Width: 1-1/4 in.
• Gauge: 18
• Coating: ZMAX
• Finish: ZMAX
• Member Size: 2x
• Country of Origin: United States

Approved Applications

• Wood-to-wood uplift tension load resistance
• Floor-to-floor clear span applications
• Edge of 2x member installations
• Exterior applications requiring corrosion resistance
• Treated-wood applications

Frequently Asked Questions

What fasteners are recommended for installing the MSTA21Z?

Install with 10d common nails or #9 x 1-1/2 in. Strong-Drive SD screws.

Why is the ZMAX coating important for this strap tie?

ZMAX galvanization offers extra corrosion resistance, making the MSTA21Z suitable for exterior and treated-wood applications where standard coatings may not provide adequate protection.

What advantage does the staggered nail pattern provide?

The staggered nail pattern is designed to help minimize wood splitting during installation, ensuring a secure connection without compromising the integrity of the wood member.

How does the MSTA21Z differ from a field-fabricated strap?

Unlike field-fabricated straps, the MSTA21Z is load rated with the correct thickness and number of fasteners, and its loads have been increased for wind and seismic forces, providing a more reliable and code-compliant connection.

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