Simpson Strong-Tie SDHR27400-R25 4" x .275 COMBO-HEAD Structural Timber Screw 25ct
The Strong-Drive SDHR Combo-Head screw is a structural fastener designed for cross-laminated timber construction, mass timber construction and general interior applications. These partially threaded, sturdy 0.394"- and 0.472"-diameter structural fasteners are designed to pull structural members together while providing excellent connection strength — especially when connecting steel plate connectors to wood. The unique “combination” head allows for effortless driving using either a hex driver bit or T40 6-lobe driver bit. The SDHR Combo-Head has an interior-grade, blue-zinc coating, a robust knurled shaft and Type-17 point for fast starts and low-torque driving.
Key Features
- Designed for use with steel side plates
- Can be driven by either a hex-head or 6-lobe driver bit
- Heavy-duty, partially threaded shaft with knurl provides strength, with superb pull-out resistance
- Type-17 point ensures fast starts, reduces installation torque and eliminates the need for predrilling in most applications
- Deep T40, 6-lobe recess for a secure drive (replacement bit: BIT40T-134)
- Interior grade blue-zinc coating
- Available in 4" and 6 1/4" lengths in two diameters: .394" and .472"
Applications - Wall-to-wall, floor-to-floor, support beams, lap joints, ledger connections, steel plate and angle connections
Specifications:
| Coating/Material | Blue-Zinc Coated |
| Length (in.) | 4 |
| Head Diameter (in.) | 0.590 |
| Shank Diameter (in.) | 0.275 |
| Drive Type | T40 6-Lobe or Hex-Head |
| Head Type | Combination |
| Thread Length | 2.15 |
| Point Type | Type-17 Point |
| Packaging Qty. | 25 |
