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Rob Cosman's Sharpening Rule

Sharpening Rule
  • Sharpening Rule
  • <iframe width="640" height="360" src="https://www.youtube.com/embed/i29-Wjwd1BY" title="" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>
  • Sharpening Rule
  • Sharpening Rule
  • Sharpening Rule
  • Sharpening Rule
  • Sharpening Rule

Rob Cosman's Sharpening Rule

Regular price $10.00 USD $5.00 USD Sale

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Full Description
Customer Reviews
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The most innovative technique in plane sharpening over the last 30 years is the "ruler trick" by my good friend, David Charlesworth.

Traditionally, a sharp cutting edge is achieved by honing the back of your plane blade until it is dead flat (this takes a while), then you hone the primary bevel to achieve a razor sharp edge. 

David Charlesworth introduced his ruler trick to save significant time while still achieving a razor sharp edge.  Instead of flattening the whole blade back, he places a thin ruler on the stone raising up the blade about 1 degree so he just hones the leading edge, not the whole back.  David's "ruler trick" works great and I always use it.

You only need one thing - a small thin ruler.  We have our 8 inch long, .018 inch thick sharpening rules custom made without ruler etchings to allow plane blades to glide smoothly across the rule when executing the "ruler trick". 

Customer Reviews

Based on 100 reviews
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E
Eric Ocson
Good things come in small packages

Small but mighty indeed! It was worth the wait (3 and a half weeks in my case - from NB Canada to Melbourne Australia). I paired this steel rule with an AdjuStar (another small but mighty tool) and RC’s plane wax. Now I’m keen to get 2x Cosman IBC 2 3/4 plane blade and chip breaker for my old Stanleys, I’m desperate to know if you’ll restock again or have you stopped selling them? I would love to get a Wood River 5 1/2 but it’s just too expensive at the moment. Keep up the great work that you do RC and the team!

D
David Mertes
Very thoughtful. Very mindful. Very demure.

Yeah, sorry about the title but it actually fits! Good addition to the sharpening kit!

M
Michael Ottman

Item as described. Works great. Excellent customer service.

T
Timothy Wozniak

A key element in the Charlesworth sharpening technique, the Cosman sharpening rule is of optimal length to fit most standard sharpening stones. Accurately described in Rob’s YouTube sharpening videos. Proud to support a small business.

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Wesley Yale
It Works as Promised

This is a simple yet effective tool to aid sharpening blades with Rob's technique.

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