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The terminology used for sharpening blades can be confusing at first. The term angle is used to mean the degrees per side, because this is the setting actually used on the sharpening equipment. When people talk about the cutting performance of the knife, they refer to the inclusive angle, which is the sum of the two sides. For a one-sided bevel, like the chisel edge used on serrated blades, the inclusive angle and sharpening angle are the same. For a double sided bevel the inclusive angle is double the sharpening angle.
Factory Blade Angle
We collected the sharpening angle used at the factory into the table below. Knife experts recommend approximately 20° as a good general purpose sharpening angle so we were a little surprised to find the big multi tool brands all sharpen at a more aggressive angle. Blades are more likely to chip or deform at lower angles, if you notice this on you can easily re-profile your edge to within the 20-25° range.
|Straight Blade Angle
|Serrated Blade Angle
(16° per side)
(15-20° per side)
(15° per side)
(20° per side)
(17-22° per side)
Factory Sharpening Services
There is nothing quite like the feel of a new multi tool fresh from the factory. Every tool is pristine and the blade is precise. You can get great results home-sharpening your knife buy why not restore your multi tool blade to original factory specs?
Victorinox has the most complete selection of services of all the major multi tool brands. Select the sharpening option on their service page, as well as anything else needed to refresh your SwissTool (or SAK).
SOG will sharpen your knife for free if you drop by their headquarters in Portland. If that is not convenient, you can also mail them your tool (link to form). They will sharpen it and send it back to you all for no charge.
Gerber offers their sharpening service for a small fee: $5 for single edge, $7.50 for double edge, $5 shipping (prices current Mar-2020). Here is a link to the Gerber service request.
We took a deep dive into what each brand covers with their warranty and what you can expect after you submit a tool for service, read our conclusions in Multi Tool Lifetime Warranty and Service: A Detailed Comparison.
How to Sharpen Straight Edge Blades
Straight edge blades are straight-forward to sharpen but there are common mistakes to avoid. One of the worst mistakes is also the most common – starting with a blade that is very dull. The best knife to learn how to sharpen is one that is moderately dull, you will definitely notice a difference once you sharpen and you can learn the right techniques.
Angle control is the most important part of sharpening a blade – knowing what angle your blade is at and keeping it consistent throughout the process. We highly recommend the Lansky Controlled Angle Sharpening systems. With coarse, medium, and fine hones and a serrated hone, the Lansky Sharpening Tool Universal system (available on Amazon) can handle all your sharpening needs for about $40. The best part is you can upgrade the system and purchase additional hones if/when you move on to more exotic knife steel.
With the Lansky system your blade is clamped and the angle is controlled at the factory angle from the table above. All you need to do is decide when to switch hones and make sure you use consistent technique through the whole process. Draw the hone across the blade from the edge toward the spine, you want to remove metal from the cutting surface to create a fresh edge with the proper geometry.
We’ve tested many pull-through sharpeners and have yet to find any that we can recommend. The carbide steel pulls metal as it travels the length of the blade instead of taking it away from the edge. With only a little more effort you can get a quality edge with the Lansky.
Stropping a Knife Blade
Remember to strop your knife blade after sharpening. This final step is key to getting the best performance out of your blade. Stropping removes the excess metal from the burr and polishes the edge. A rough edge may feel sharper to your thumb, but that is just the weak metal pieces from the burr and they are gone after the first cut. A polished edge is truly sharp.
You don’t need a fancy strop, the backside of a leather belt works fine. Simply lay it flat on a table or counter top so it stays flat. The stropping motion is opposite the honing motion. You want to hold the knife blade at the same angle and draw it back across the leather (going forward would cut the leather and now you need a new strop).
Alternate sides and strop your knife 6-7 times per side and then rinse your blade with warm water and wipe clean to dry it. Give your blade a final protective coating and you are done.
How to Sharpen Serrated Blades
The Lansky Universal system comes with a hone for serrated blades. Draw the hone only along the beveled edge until you form a burr on the edge. You can feel the burr by pulling your thumb from the flat side of the blade. If you don’t have a burr you need to continue sharpening with the hone.
If you don’t have a hone you can also pick up a small round diamond file to sharpen the serrations. Because each groove needs to be sharpened separately we find this method easier for serrated blades that have different size and shape teeth. Here is our favorite diamond file on Amazon, the reversible rod works on almost any serrated blade.
Finish sharpening by stropping just like with a straight blade.
How to Sharpen Multi Tool Scissors
Don’t sharpen scissors until you’ve had some success and confidence sharpening knife blades. Scissors are less forgiving of mistakes and you need to match the original factory angle precisely.
To verify you are using the right sharpening angle use the Sharpie trick. Color the beveled edge of the scissors you are sharpening with Sharpie and then make 2-3 passes with the hone. Look at the blade edge to see if you need to make any adjustments, you want to see fresh steel at the very edge of the blade. If the edge is still black then you need to increase your sharpening angle.
The most critical aspect with sharpening scissors is to keep a completely flat straight edge. Any waviness will lower the cutting effectiveness of the scissors or they may not cut at all.