Self-countersinking into even the hardest woods
Cutting pockets under the head transport drill dust away while cutting a perfectly clean screw hole
Screw head closes the hole off with precision, leaving no damaged fibres around the head
CEE thread (on 50mm and longer R4™ screws) enlarges the screw hole, increases the screw's drawing strength, reduces the friction on the screw shank and lowers the driving torque
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GRK Selection Guide
The following sizes are available from stock:
R4™ Stainless Steel Options and Quantities
| Gauge | Length | Handy Pak | Pro Pak | Bulk Box |
| 4.0 |
30mm |
100 |
n/a |
n/a |
| 4.5 |
50mm |
100 |
627 |
4000 |
| 4.5 |
60mm |
100 |
n/a |
n/a |
| 5.0 |
60mm |
100 |
425 |
2500 |
| 5.0 |
70mm |
n/a |
350 |
2000 |
| 5.0 |
80mm |
100 |
305 |
1500 |
| 5.0 |
100mm |
n/a |
255 |
1000 |
Star Drive Bits
The R4™ stainless steel multi purpose screw takes the following bit sizes:
- 4.0 (#8) gauge - T15
- 4.5 (#9), 5.0 (#10) - T25
One star drive bit is supplied free of charge with each 1000 (or part thereof) screws ordered.
Silva Timber is the exclusive distributor for GRK Fasteners™, manufacturer of 'The Industry's Toughest Screws'. All of GRK's products are built to last and have unique labour saving features.
Why use GRK Screws?
GRK Screws are packed with unique features, saving you time and money:
- CEE Thread enlarges the screw hole, increases the drawing strength, reduces friction, lowers the driving torque and reduces splitting
- Drive into hardwoods and softwoods easily without pre-drililng
- W-Cut™ Thread Design - patented design acts like a saw blade, cutting through fibrous materials and reducing the amount of torque required to install the screw
- Zip-Tip™ - designed for fast starts in any fibrous materials
GRK Screws won't fail where others do, driving in effortlessly and significantly reducing the installation time
Climatek™ is exclusive to GRK products. Originally designed for the Navy, GRK has adapted this coating for fasteners and rigourously tests it to meet and exceed all standards. GRK's Climatek™ coating is virtually indistinguishable from brass and its colour matches almost all wood finishes.
GRK Fasteners revolutionary Climatek™ coating is available only on GRK products.
GRK's Climatek™ coating consists of a total of six layers of various materials, including three layers of zinc-polymer.
Climatek™ has been tested for salt spray resistance, and more importantly, for Kesternich durability. Kesternich cycles are a more advanced way of testing a coated material. Each Kesternich cycle simulates heat, cold, wind, water, salt as well as a variety of other elements, whereas salt spray merely uses salt water for its tests.
Climatek™ passed 29 Kesternich cycles, making it the most advanced coating of its kind.
PHEINOX™ stainless steel products are hardened and come with a limited lifetime guarantee against staining and rusting.
