No Products in the Cart
Hapstone S4 Family
Hapstone S4 is a compact, minimalist guided sharpening system for 4-inch stones, offering precise blade fixation, adjustable sharpening angles, and easy access to both sides of the knife for beginners and experienced users alike.
Clamping System
The mechanical clamping system keeps the knife securely positioned throughout sharpening, minimizing unwanted movement and improving control.
Hapstone S4 accommodates blades from 40 to 230 mm (1.6–9.1 in) in length, up to 50 mm (2.0 in) wide and 6 mm (0.24 in) thick. The system is suitable for kitchen knives, EDC folders, hunting knives, and outdoor blades.
Angle Adjustment
The S4 offers an adjustable sharpening angle range of 13° to 35° per side, allowing users to work with different blade geometries and edge profiles.
An integrated angle scale provides convenient adjustment. For additional precision, the system supports the Hapstone Mini Digital Angle Gauge with an optional zero-level adapter, which provides a reference surface for zeroing the gauge
Please note: The Mini Digital Angle Gauge and zero-level adapter are sold separately.
Ease of Use
Hapstone S4 makes accurate knife sharpening straightforward and convenient. The system securely holds the blade while guiding the sharpening stone at a consistent angle, helping achieve even, repeatable results.
Simply clamp the knife, select the desired angle, and start sharpening. The compact construction makes the S4 easy to use, transport, and store.
Sharpening Stones
Designed for 4 × 1 in (100 × 25 mm) sharpening stones, the S4 supports stones with or without aluminum blanks.
Modular Design
Hapstone S4 features a modular construction that allows users to expand its functionality with optional accessories.
Hapstone RS and R2 clamps are compatible with the S4, although certain clamp configurations may have spacing limitations.
Dedicated accessories, including an optional scissor sharpening module, provide additional sharpening possibilities.
Key Features
Minimalist, Compact Design: Small footprint for convenient sharpening and storage.
4-Inch Stone Compatibility: Supports mounted and unmounted 4 × 1-inch sharpening stones.
Adjustable Sharpening Angles: 13°–35° per side.
Secure Blade Clamping: Stable positioning for accurate sharpening.
Convenient Blade Rotation: Sharpen both sides without removing the knife.
Versatile Blade Clamping: Holds blades from 40 to 230 mm in length.
Modular Construction: Compatible with selected Hapstone clamps and optional accessories.
What's Included
| 1 × Hapstone S4 Knife Sharpening System |
| 1 × Assembly Instruction Manual |
| 1 × Marker for Sharpening Angle Control |
| Hex Keys for Knife Clamping and Assembly |
| 1 × Protective Shipping Box |
Note: Sharpening stones, Mini Digital Angle Gauge, zero-level adapter, and optional modules are sold separately.
Technical Details
| Model | Hapstone S4 |
|---|---|
| Type | Guided Knife Sharpening System |
| Blade Length | 40–230 mm (1.6–9.1 in) |
| Maximum Blade Width | 50 mm (2.0 in) |
| Maximum Blade Thickness | 6 mm (0.24 in) |
| Sharpening Angle | 13°–35° per side |
| Stone Compatibility | 4 × 1 in (100 × 25 mm) |
| Supported Stone Types | With or Without Aluminum Blanks |
| Angle Gauge Compatibility | Hapstone Mini Digital Angle Gauge Only |
| Compatible Clamps | Hapstone S4, RS, and R2 |
| Scissor Sharpening | Optional Module |
| Sharpening Stones | Not Included |
| Manufacturer's Warranty | 5 Years |
