As of 2026, the global push for green, low-carbon construction has significantly increased the share of timber structures in residential, public, and (cultural tourism) projects. Amid this trend, a small but vital component — the metal nail plate (also known as a timber connector or truss plate) — is drawing growing attention from engineers and specifiers.
A nail plate is a stamped steel sheet used to connect timber members in truss assemblies. Its teeth are pressed into the wood under hydraulic or mechanical pressure, transferring loads between members. Although simple in appearance, the material thickness, zinc coating grade, and tooth pattern of a nail plate directly determine the joint capacity and service life of a timber structure.
In mature timber construction markets such as North America, Europe, and Japan, the corrosion resistance of nail plates is a key acceptance criterion. As timber structures increasingly move into outdoor, high-humidity, and coastal environments, premature rusting of conventional electro-galvanized nail plates has become a frequent issue.
In late 2025, a field study published by a North American wood truss association revealed that among projects exposed outdoors for 3–5 years, some low-grade galvanized nail plates showed significant red rust, and in a few cases, joint failures occurred. The report explicitly recommended that for outdoor or humid environments, hot-dip galvanized (HDG) nail plates with a double-sided coating weight of no less than Z275 should be used.
Z275 indicates a total double-sided zinc coating of 275 g/m², offering substantially better corrosion protection compared to standard electro-galvanized coatings (typically only a few tens of grams). In de-icing salt environments, coastal salt spray, or acidic/alkaline industrial settings, stainless steel nail plates are also becoming a more common technical choice.
According to QYResearch, the global truss plate (nailed joint) market is projected to reach approximately US21millionby2032,withacompoundannualgrowthrateofaround6.21.67 billion in 2026, reflects the increasing complexity of modern timber joints.
This growth is not driven by the nail plate alone, but by the industry's transition from low-rise residential timber framing to multi-story public buildings and large-span venues. Larger spans and higher loads demand more refined nail plate specifications — including thickness, tooth geometry, and material strength.
In engineering practice, light wood frame trusses typically use 1.0mm thick nail plates, while heavy or long-span trusses often require 1.5mm thickness to ensure adequate pull-out and shear capacity.
Commonly used sizes include:
In addition, custom non-standard sizes are increasingly demanded on the engineering side. Different truss angles and tooth patterns (dense, staggered, or variable pitch) require dedicated tooling, which standard off-the-shelf products often cannot fully cover.
A structural engineer specializing in timber construction told our correspondent: "Many people think nail plates are simple — just stamping a piece of steel. But what really determines joint longevity is the uniformity of the zinc coating, the hardness and angle of the teeth, and the yield strength of the base material. If any one of these is substandard, you have a hidden safety risk a few years down the road."
In his view, while the domestic timber construction industry has grown rapidly in recent years, the reliable supply of high-quality connectors in this niche category still has gaps. Some projects, in an effort to cut costs, opt for nail plates with insufficient zinc coating or below-grade thickness — compromising long-term safety.
As a reference for engineering specification, the following parameters represent what is currently expected from outdoor-grade timber nail plates. The S-SEN brand offers a product line covering these typical ranges:
| Parameter | Specification |
|---|---|
| Application scenarios | Timber structure construction and truss connections |
| Material | HDG340 + Z275 hot-dip galvanized steel (stainless steel available on request) |
| Thickness | 1.0mm – 1.5mm |
| Standard sizes (mm) | 75×50, 100×50, 100×100, 150×100 |
| Customization | Non-standard sizes and tooth patterns available |
These specifications provide a practical benchmark for engineers and specifiers evaluating nail plates for durable timber connections.
