Construction Fasteners: Types, Uses & How to Choose the Right One

TLDR: Construction fasteners include structural bolts, hex cap screws, lag screws, anchor bolts, nails, and specialty hardware for framing, roofing, masonry, and steel connections. The right choice depends on the material being joined, load requirements, and environmental exposure. Corrosion resistance and strength grade are the two most critical selection factors on any job site.

Table of Contents

• What Are Construction Fasteners?
• Types of Construction Fasteners
• Materials & Coatings
• How to Choose the Right Construction Fastener
• Common Mistakes to Avoid
• Where to Buy Construction Fasteners

What Are Construction Fasteners?

Construction fasteners are mechanical devices that connect structural and non-structural components in building and infrastructure projects. They hold together everything from wood framing and steel beams to concrete anchors and roofing panels.

Every connection on a job site depends on the right fastener. Use the wrong grade and the joint fails under load. Use the wrong coating outdoors and corrosion compromises structural integrity within a few years. Use the wrong length and you either miss the substrate entirely or blow through the back face.

According to Fasteners Etc., the construction fastener world divides into two broad categories: permanent fasteners (nails, rivets, weld studs) and non-permanent or removable fasteners (bolts, screws, anchors). Most structural connections rely on removable fasteners so joints can be inspected, retorqued, or replaced over the life of the structure.

Types of Construction Fasteners

Structural Bolts (A325 / A490)

Structural bolts are the backbone of steel-to-steel construction connections — used in bridges, steel frames, and heavy structural assemblies. A325 bolts have a minimum tensile strength of 120 ksi; A490 reaches 150 ksi for higher-demand applications. Both require hardened washers and heavy hex nuts to distribute load properly.

Hex Cap Screws & Bolts

Standard hex head bolts in Grade 5 and Grade 8 cover the majority of construction hardware connections — equipment mounting, machinery, structural brackets, and general assembly. Grade 8 bolts (150,000 PSI tensile) handle the highest-load connections. Browse our hex cap screw selection for both inch and metric sizes.

Lag Screws (Lag Bolts)

Lag screws thread directly into wood without a nut. They're the go-to fastener for heavy wood framing connections — ledger boards, beam-to-post connections, and deck framing. Always pre-drill a pilot hole to prevent splitting.

Anchor Bolts & Concrete Anchors

Anchor bolts embed in concrete to attach structural steel columns, sill plates, and equipment bases. Expansion anchors, wedge anchors, and epoxy anchors cover different load requirements and base material conditions.

Self-Drilling Screws (Tek Screws)

Tek screws drill their own pilot hole and thread simultaneously, eliminating the need for pre-drilling in metal framing and steel decking applications. Common in metal stud framing, HVAC ductwork, and light-gauge steel connections.

Nuts & Washers for Construction

Every structural bolt needs the right nut and washer. Heavy hex nuts pair with structural bolts. Flat washers distribute load across the bearing surface. For outdoor and high-vibration connections, flange nuts and lock washers add resistance to loosening over time.

Plow Bolts & Specialty Hardware

For heavy equipment, snow removal, and road construction, plow bolts (dome head bolts) provide a flush, snag-free surface on scraper blades and cutting edges. These are specialty fasteners that big-box stores rarely stock.

Materials & Coatings

Material and coating choice on a construction site isn't optional — it's a code and longevity issue.

Critical note for pressure-treated lumber: Standard zinc-plated fasteners corrode rapidly in contact with modern pressure-treated (ACQ/CA) lumber. Always use hot-dip galvanized (HDG) or stainless steel fasteners for deck framing, fence posts, and any structural connection to treated wood. This is both a longevity and building-code requirement in most jurisdictions. Source: Green Building Canada

How to Choose the Right Construction Fastener

Work through these four decision points on every connection:

1. What materials are you joining?
Wood-to-wood: lag screws, structural screws, or through-bolts. Steel-to-steel: structural bolts (A325/A490) or Grade 8 hex bolts. Steel-to-concrete: anchor bolts or wedge anchors. Metal framing: self-drilling Tek screws.

2. What are the load requirements?
Shear loads (lateral forces) and tensile loads (pull-out forces) determine grade. A structural engineer specifies fastener grades on permitted work. For non-permitted work, use Grade 8 for high-load connections and Grade 5 for general assembly.

3. What is the environment?
Indoor/dry: zinc-plated steel. Outdoor, exposed: hot-dip galvanized. Coastal or chemical: stainless steel. Pressure-treated lumber: always HDG or stainless.

4. Does the connection need inspection or adjustment?
Bolted connections allow inspection, retorquing, and replacement. Use bolts over nails or rivets anywhere future access matters — especially in seismic zones where joints need periodic inspection.

Common Mistakes to Avoid

Using zinc-plated fasteners with treated lumber. Causes rapid corrosion. Use HDG or stainless.

Mismatching bolt and nut grades. A Grade 8 bolt with a Grade 2 nut will fail at the nut. Always match grades.

Skipping washers on structural connections. Without a washer, the bolt head or nut digs into the material, reducing the effective bearing area and increasing the risk of pull-through.

Using standard hex bolts where structural bolts are specified. A325 and A490 structural bolts have specific proof load and installation requirements. Substituting standard bolts in a structural connection is a code violation.

Under-torquing or over-torquing. Both cause joint failure. Use a torque wrench on critical connections and follow the manufacturer's torque specification.

Where to Buy Construction Fasteners

For contractors and construction operations, inventory availability matters as much as price. A delayed project because a supplier is back-ordered on 3/4" A325 bolts costs far more than a few cents per fastener.

NutsandBolts.com stocks structural bolts, Grade 8 hex cap screws, plow bolts, and specialty construction hardware — in stock and ready to ship. Our nut, bolt, and washer assortment kits keep job site trailers and shop trucks stocked with the sizes you reach for most. For operations with ongoing hardware needs, our B2B account program offers custom pricing, a dedicated account rep, and one-click reordering so you never run short mid-project.

Shop construction fasteners or contact our team — we're available 7 days a week.

Conclusion

Construction fasteners are not interchangeable. Grade, material, coating, and type all affect whether a joint holds for decades or fails in the first season. Match the fastener to the load, the material, and the environment — and work with a supplier who has what you need in stock, not on a 3-week back-order.