Categories of Construction Fasteners
Structural Steel Bolts
ASTM A325 / F3125 Grade A325
Standard structural bolts. 120 ksi tensile strength. Used in:
- Steel-to-steel structural connections
- Bridge construction
- Heavy machinery foundations
- Industrial buildings
ASTM A490 / F3125 Grade A490
High-strength structural bolts. 150 ksi tensile strength. Used in:
- Critical structural connections
- Long-span bridges
- High-rise buildings
- Heavy industrial structures
Lag Bolts (Lag Screws)
For heavy-duty wood connections without through-bolting:
- Deck ledger boards
- Heavy wood-to-wood framing
- Mounting equipment to wood
- Outdoor structures
Concrete & Masonry Anchors
Wedge Anchors
Heavy-duty, high-load. The most reliable mechanical anchor for permanent installations. Used for:
- Equipment mounting to concrete
- Structural connections
- Heavy bracket installations
Sleeve Anchors
Medium-duty, easier to install than wedge anchors. Good for:
- Light to medium equipment
- Brick and block walls
- Where slight hole variation is acceptable
Deck & Construction Screws
Specialized screws for deck and exterior construction:
- Coated steel (Western Red Cedar compatible)
- Stainless steel (coastal/marine deck)
- Star drive (T20/T25) for high torque applications
- Self-drilling tips for hardwood and composite
 Self-Drilling Screws (Tek Screws)
For metal-to-metal connections in steel framing, metal roofing, and HVAC:
- #2 point: 24-9 gauge metal
- #3 point: 16-3 gauge metal
- #4 point: up to 1/2" plate
- #5 point: up to 5/8" plate
Code Compliance
Always verify your fastener selection meets:
Local building codes
May specify A325/A490 for certain structural connections
AISC standards
American Institute of Steel Construction requirements
AWC standards
American Wood Council requirements for wood construction
ICC-ES reports
Mandatory for concrete anchors in seismic zones
Hot-Dip Galvanizing for Exterior Construction
For outdoor construction fasteners, hot-dipped galvanized (HDG) provides 20-50+ year service life. The thick zinc coating protects against rust through self-sacrificing corrosion.
A490 bolts must NEVER be hot-dip galvanized
Hydrogen embrittlement risk causes catastrophic failure- For A490 corrosion protection, use mechanical galvanizing or thermal diffusion coating- Match all components — galvanize bolts, washers, AND nuts
Sample Construction Fastener Specifications
| Application | Fastener | Grade | Finish |
|---|---|---|---|
| Steel-to-steel structural connection | 7/8"-9 A325 Heavy Hex Bolt | A325 | HDG or plain |
| Deck ledger board to wood framing | 1/2"-13 x 6" Lag Bolt | A307 | HDG |
| Equipment to concrete pad | 1/2"-13 x 4" Wedge Anchor | Carbon steel | Zinc plated |
| Metal roofing to steel framing | 12 x 1" Self-Drilling Screw | 410 stainless | EPDM washer head |
| Wood deck boards | #10 x 2 1/2" Deck Screw | Coated steel | Brown coating |
| Stainless coastal deck | #10 x 3" Square Drive Deck Screw | 305 stainless | Plain |