HARDEST STEEL: Can Tormek & CBN Sharpen Spyderco Sage5 in REX 121 (71 HRC) to a Mirror Edge

This was, without a doubt, the most challenging knife of my career. The Spyderco Sage 5 in *Rex 121* is regarded as the hardest knife steel on the planet, clocking in at 71 HRC. My client was concerned—could a CBN wheel even touch this steel?

This video is the silent, intense, blow-by-blow technical progression of how I was able to transform this new knife's factory bevel into a razor-sharp, mirror-polished apex. The challenge was to achieve a sub-105g result while minimizing the risk of mistakes on such a unique material.

The Full Technical Progression:

Initial Grinding & Safety: Tormek T8 with 800 Grit CBN wheel (@ 15.5°)
Mirror Polish Base: 1200 Grit CBN wheel (4 passes)
Burr Root Removal: Rock Hard Felt Wheel (6 Micron @ 15.2°)
Apex Refinement & Polish: Tormek Leather Wheel (3 Micron Diamond @ 15.5°)
Final Mirror Edge: Rock Hard Felt Wheel (1 Micron Diamond @ 15.5°)

The final result: *104 grams* on the sharpness tester, an unbelievable result that sets a new bar for REX 121 steel. Stick around to the end for 20 seconds of high-res photos to inspect the flawless new bevel!

Join the conversation and challenge me on the Sharpeners Discord:   / discord  

Timecode:
0:00 The World's Hardest Steel: Rex 121 Challenge
0:30 Sharpening Begins: CBN 800 Grit Safety Pass
2:52 The Focus: Entering the Silent Sharpening Progression
4:40 The Stress of Sharpening the Most Important Knife of My Career
5:09 Maintaining the Perfect Angle
10:54 The Final Sharpness Test: Did We Hit Razor Sharp?
11:45 I Just Set The Bar For Professional Sharpening
12:34 High-Resolution Final Knife Photos

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