§ 01
System Summary
6pc
Diamond stones included
1.5mm
Lead screw angle step
3grit
Stages: 240 / 600 / 1000
2side
Simultaneous both-side sharpening
The KMFS Rival Diamond is a precision guided knife-sharpening system fully CNC-machined from solid billet stock. Its key innovation is a coupled lead-screw mechanism that links both left and right sharpening arms, guaranteeing an identical bevel angle on both sides of the blade simultaneously. The trapezoidal articulated nut on the lead screw also compensates for the raised tip bevel common on many knives. All structural parts are made from aerospace-grade Ergal 7075-T651 duralumin. No plastic structural elements anywhere in the system.
§ 02
Hardware Components
Knife Clamp Vice
Main knife-securing body with professional spindle screw
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MaterialENAW 7075 T651 Duralumin
SurfaceHard colour anodising (black)
Screw TypeProfessional spindle screw
Fastening KeyAllen key (included)
Knife PositionCutting edge facing up
The vice body is machined from a single solid block — no assembled joints or tolerance stacking. The spindle screw (upgraded from earlier versions) gives precise, repeatable clamping force without over-torquing. Knife is mounted with cutting edge facing upward.
Lead Screw Assembly
Coupled left-right angle-setting mechanism with trapezoidal nut
+
Lead Screw MaterialStainless steel
Step Resolution1.5 mm increments
Nut TypeTrapezoidal articulated nut
Nut BushingBronze
SymmetryBound left/right movement
The coupled lead screw binds the movement of both sharpening arms so they always move to equal and opposite angles. The 1.5 mm step increments translate to precise angle settings. The trapezoidal nut geometry naturally counteracts the tip-bevel effect, keeping the stone flat on the blade throughout the full stroke.
Guide Rod Assembly
Stainless steel twin guide rods for stone holder travel
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Rod MaterialStainless steel
Rod Count2 per side (4 total)
Bushing MaterialBronze
BacklashNone
Stainless steel guide rods run through bronze bushings to provide smooth, zero-play linear stone travel. The stainless-on-bronze pairing is self-lubricating and resistant to corrosion from water or honing slurry.
Whetstone Holders (×2)
Locking flap segment holders for fast stone swaps
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Locking MechanismFlap-type quick-release
Stone FormatKMFS standard paddle
Qty2 holders (one per side)
CompatibilityAll KMFS Rival stones
The flap-locking design allows stone grit changes in seconds — no screws to lose in the field. Each holder secures one stone per side; users work both sides of the blade simultaneously with the same grit before switching to the next stage.
Table Fastening Clamp
C-clamp for rigid bench or tabletop mounting
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TypeC-clamp / G-clamp style
MaterialDuralumin / stainless hardware
MountingAny table edge or workbench
The table clamp attaches the system rigidly to any bench or tabletop edge. Rubber contact pads protect surfaces from marring. The system can also be used without the clamp by holding in-hand if needed.
Blade Angle Gauge
Stainless steel protractor for measuring and setting bevel angles
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MaterialStainless steel
FunctionMeasure existing bevel before sharpening
UseSet lead screw to matching position
The angle gauge lets users measure the existing bevel angle of any knife before sharpening, allowing them to match or change it precisely using the lead screw setting. Particularly important when re-profiling a knife to a new angle.
§ 03
Angle Setting Mechanism
| Feature | Specification | Benefit |
|---|---|---|
| Lead screw step | 1.5 mm increments | Precise, repeatable angle setting |
| Arm coupling | Bound left + right movement | Identical angle both sides — guaranteed |
| Nut geometry | Trapezoidal articulated nut | Compensates for raised knife tip bevel |
| Bushing material | Bronze (lead screw + guide rod) | Self-lubricating, long service life |
| Angle verification | Included stainless steel gauge | Measure before and after sharpening |
§ 04
Abrasives (Included)
| Grit | Type | Coating | Qty | Use Stage |
|---|---|---|---|---|
| 240 | Diamond | DLC | 2 pcs | Reprofiling / coarse stock removal |
| 600 | Diamond | DLC | 2 pcs | Bevel refinement / burr raising |
| 1000 | Diamond | DLC | 2 pcs | Edge finishing / burr removal |
| 3000 (optional) | Ruby stone | — | 2 pcs | Polish / mirror edge (sold separately) |
| 1500–5000 (optional) | Diamond lapping film | — | Set | Ultra-fine finishing (sold separately) |
DLC = Diamond-Like Carbon coating. All stones operate dry. Stone lifespan: approx. 50 unique knives on 240 grit (first sharpening); 200–500 resharpenings on finer grits. All 6 stones are identical in thickness — no angle re-zeroing needed when swapping grits.
§ 05
Key Design Features
Solid-Billet CNC Construction
Every structural part is machined from a single block of ENAW 7075-T651 duralumin — maximum rigidity, no assembled joints, no tolerance stacking.
Coupled Symmetric Arms
Bound left/right arm movement guarantees equal angles on both bevels simultaneously — impossible to accidentally set mismatched angles.
Trapezoidal Nut Tip Compensation
The articulated trapezoidal nut on the lead screw naturally reduces the raised-bevel effect at the knife tip, maintaining flat stone contact along the full blade.
Uniform Stone Thickness
All included stones share identical thickness — swap grits freely without re-zeroing the angle setting. No adjustment per stone change.
Hard Coat Anodising
All aluminium parts receive hard colour anodising (20–80 µm), providing exceptional corrosion resistance and surface hardness for lifelong use.
Bronze Bushing System
Bronze bushings on both the lead screw and guide rods provide self-lubricating, play-free motion that improves with use rather than wearing loose.
§ 06
Materials Register
| Component | Material | Grade / Spec | Finish |
|---|---|---|---|
| Vice body / main chassis | Duralumin alloy | ENAW 7075 T651 | Hard colour anodise (black) |
| Arm assemblies (×2) | Duralumin alloy | ENAW 7075 T651 | Hard colour anodise (black) |
| Lead screw | Stainless steel | — | As-machined |
| Guide bars / bolts | Stainless steel | — | As-machined |
| Angle gauge | Stainless steel | — | Polished |
| Lead bushings (guide rods) | Bronze | — | As-machined |
| Lead screw bushings | Bronze | — | As-machined |
| Articulated nut | Bronze | Trapezoidal | As-machined |
| Diamond whetstones (×6) | Diamond abrasive | DLC-coated, 240 / 600 / 1000 grit | DLC coating |
| Carrying case | Plastic (PP) | — | Soft PUR foam lining |
§ 07
Package Contents
| # | Item | Qty | Notes |
|---|---|---|---|
| 1 | KMFS Rival sharpening system (assembled) | 1 | Vice + lead screw + guide rods + arms |
| 2 | Whetstone holders / segment fasteners | 2 | Flap-locking, one per arm |
| 3 | Table fastening C-clamp | 1 | For workbench mounting |
| 4 | Blade angle gauge | 1 | Stainless steel protractor |
| 5 | Allen key (knife fastening) | 1 | For vice clamping screw |
| 6 | DLC diamond whetstone, 240 grit | 2 | Coarse reprofiling (1 per side) |
| 7 | DLC diamond whetstone, 600 grit | 2 | Bevel refinement (1 per side) |
| 8 | DLC diamond whetstone, 1000 grit | 2 | Edge finishing (1 per side) |
| 9 | Plastic carrying case with PUR foam inlay | 1 | All components stored securely |