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R4™ Self-Countersinking Flat Head Multi Purpose Screw, 100-Piece, #9 X 2-1/2"
- Mfg.#
- GRKF 103101
- Sku#
- 1150382
- Fast Bite Tip: Eliminates pre-drilling and provides a fast start for one-step installation.
- W-Cut™: Low torque, faster drive.
- Precision Fit: Reduces wobble between R4 screws and GRK bits for improved productivity
- Star Drive: Zero stripping, with 6 points of contact.
- Optimized Thread Length: Improves clamping force for increased drawing power.
* Estimated stock levels as of Thu, Mar 19, 2026. All items subject to prior sale. Prices may vary between stores and online. Please call ahead to confirm availability of items marked as Limited Stock.
Description
GRK’s R4™ self-countersinking screw has a patented underhead with saw-blade like cutting teeth and six self-contained cutting pockets. Together they act similar to a circular saw-blade, transporting the drill dust away from the edge of the screw hole while cutting a perfectly clean hole into even the most brittle materials without cracking any surface treatment.
This design enhances the R4™’s versatility by allowing the fastener to countersink into even the hardest woods. The head of the screw closes the hole off with precision, leaving no damaged fibers around the head.
R4™ screws 3-1/8 in and longer have a four threaded CEE Thread. This enlarges the screw hole for the non-threaded portion of the fastener, allowing the wood to settle easily. It increases the screw’s drawing strength and reduces the friction on the screw shank that lowers the driving torque.
Specifications
General
| Applicable Materials | Cement, Plastic, Wood |
|---|---|
| Application | Interior and Exterior Remodeling, Multi-Purpose Framing, Porches and Patios, Fencing, Exterior Structures |
| Color | Gold |
| Drive | Torx |
| Drive Size | T-25 |
| Drive Style | Recessed Star |
| Drive Type | T-25 Star |
| Driver Bit Size | T-25 |
| Finish | Climatek™Coating |
| Head Style | Flat |
| Head Type | Bugle |
| Includes | Driver Bit |
| Indoor/Outdoor | Indoor/Outdoor |
| Length Under Head | 2.457 in |
| Material | Steel |
| Pack Qty | 100 |
| Point Type | Zip-Tip™ |
| Series | R4™ |
| Thread Length | 1.575 in |
| Thread Pitch | 2.2 in |
| Thread Size | #9 |
| Thread Type | Coarse W-Cut |
| Type | Multi-Purpose |
Dimensions
| Diameter | #9 |
|---|---|
| Length | 2.5 in |
| Size | #9 X 2.5 in |
Manufacturing Details
The following information is subject to change without notice
| Country of Origin | China |
|---|---|
| Prop 65 Warning |
This product can expose you to a chemical (or chemicals) that are known to the State of California to cause cancer or reproductive harm. For more information go to www.P65Warnings.ca.gov
|
Label Information
| Certification, Codes, Standards | ACQ Rated ; ESR-3201 approved for structural applications |
|---|
Related Documents
Brochure (PDF)
Msds (PDF)
