How to sharpen a 440A fixed blade?

D

duller

Joined
Apr 14, 2007
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242
Hi

I'm about to sharpen a good sized fixed blade made of 440A stainless steel for the first time using an EdgePro Apex.

The blade is tempered to 50-55RC.

I've practiced on a few inexpensive knives.

Are there any tricks or tips I should know besides the basics of matching the angle and starting coarse and working towards the finer grits?

440A doesn't seem to be too popular in the forum post.

Why?
 
duller said:
Hi

I'm about to sharpen a good sized fixed blade made of 440A stainless steel for the first time using an EdgePro Apex.

The blade is tempered to 50-55RC.

I've practiced on a few inexpensive knives.

Are there any tricks or tips I should know besides the basics of matching the angle and starting coarse and working towards the finer grits?

440A doesn't seem to be too popular in the forum post.

Why?
Click to expand...

For folders there are a lot of steels that hold an edge better. Edge holding is usually a premium quality in a folder.
For fixed blades there are carbon steels that hold an edge better and are easier to resharpen.
A lot of 440A gets a poor heat treat because it is often used on inexpensive knives. So a lot of folks have only tried poorly heat treated 440A and develop an overly poor opinion of it. Kershaw uses a lot of 440A and you don't see complaints about their knives. They do a good heat treat on the stuff.

I think 440A is a reasonable choice for a large folder if a stainless blade is required or desired. 440A has pretty good corrosion resistance.

======================================================
I don't use an Apex, but it is recommended that you use tape to protect the blade from being scratched.

From the Edgepro website: http://edgeproinc.com/Instructions.htm

❏SHARPENING WITHOUT SCRATCHING THE BLADE ( For Polished or Engraved Knives ).​


■ Cover both sides of the blade with “ Long Mask” ( Blue Painters Tape , available at any hardware store ). Trim off the excess tape with a knife. Then trim the tape off the Edge Bevel so it won’t gum up the Stone.​
 
if you want it to be more of a sharp knife than a chopper 15-20 seems to be a decent angle for both sides. 440A is the lower end of the 440 steels. It does have high corrosion resistance though.
 
My edgepro will but a nice edge on 440a pretty fast, kind of a soft steel. Easy to sharpen, hard to keep sharp. I agree 15-20 is a nice medium. If you want more of a slicer, a couple passes at a different angle is all it takes.
 
If it's a veggie or meat slicer with no contact with bones, I've had good experience with 15 to 18 degrees per side, but have not tried going more acute with 440A.

Buzz
 
I've reprofiled some of my kitchen knives in 420 to 15 degrees per side, but they are used for vegetables and meat only, not bones or other relatively rough cutting. 50 to 55 is a pretty large range for hardness. Thats one of the reasons it has a poor reputation, as already mentioned. It frequently gets used in cheap knives and has a corresponding cheap heat treatment. You could start with lower angles and work your way up until the edge stops taking damage, or go the other way and start at 20-25 degrees and go down until the edge starts taking damage, the microbevel back to the last edge that didnt have damage. This is quite time consuming, taking several sharpenings, but it can be done over a season of use, and at the end you will have the best cutting edge that doesnt take damage for the uses and manner of use for your purposes. If the hardness is as low as you say, you might consider a file as a first step, if you have damage to remove or a lot of rebeveling to do, reducing from say a 25 degree angle on each side to a 20 or 15 degree angle per side.
 
I have a survival knife bought in the 80s made by Marto in Spain. It has a hollow knife handle and it's called the Explora knife. It is in 440A rc 54, looks very nice and comes with a lot of small survival stuff. The features on the knive are quite innovative. I was just wondering how well this knife is rated.

Thanks.
 
knarfeng said:
Kershaw uses a lot of 440A and you don't see complaints about their knives.
Kershaw is presently switching to 13C26 because it's oh so much better as it takes and holds a terrific edge. After all, they make razor blades out of 13C26.

From Kershaw representative:

13C26 Changeover Born On Dates

--------------------------------------------------------------------------------

As most of you may now know, we are in the very tough process of changing over all of our knife blades that utilize 440A over to Sandvik 13C26.

The way we have decided to identify the change in steel will be by the "born on date" (these dates are engraved on every blade). The starting point for this modification are blades that are marked "July 07" will be 13C26 steel, any knife born prior is 440A.

The following knives marked with July 07 will now be 13C26 steel:

*Leek (1660, 1660ST, 1660CKT, 1600CKTST, 1660BR, 1660BB, 1660Trout, 1660VIB, 1660VIBST)

*Centofonte/Onion's (1610, 1615)

*Mini Mojito

*Baby Boa

*Blackout (1550, 1550ST)

*Whirlwind (1560, 1560ST, 1560RMEF)

*Blur (1670SG10, 1670RD, 1670RDST, 1670TBLKST, 1670BLK, 1670BLKST, 1675RDST, 1675BLKST)

Thanks for the patience with all of this.


To insure that there is no confusion, the Speed Bump, Cyclone's, Need's Work, JYD's, Groove's, ET's, and Storm's have always been produced with 13C26.
__________________
Thomas
Kershaw Knives
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Click to expand...
 
How dull is this knife and are you happy with the acuteness of the original edge? If it is just a little dull and you were happy with the original edge geometry then I would just follow the basic EdgePro Apex instructions. To match your original angle paint the edge bevel with a black felt tip marker. Try and guesstimate the angle that matches the old honing bevel and do a few honing strokes. Look for a bright strip showing where the honing removed the black from the edge. If the black is removed only at the very edge your honing angle is too high. Try moving your hone angle lower, paint the edge again and repeat until you start removing the ink along most of the old honing bevel. If you start out with the ink getting removed at the top of the bevel (the side of the bevel away from the apex of the edge) you will want to adjust your honing angle higher until you match.

Commonly large fixed blade knives with 440A blades are ground to a much higher (more obtuse) angle than you want for good performance. For example you might find that none of your Apex angles is high enough to match the original bevel. In that case you should reduce the angle. It might take an extremely long time to do that with an EdgePro. If the blade is only 50-55RC hard (that is extremely soft) you could reduce the angle by filing the blade freehand. That is what I would do with a machete and your blade is about that soft. I use a long smooth bastard file for the purpose. I would target a final honing angle in the 15 to 20 degree per side range. I would finish it with the EdgePro.
 
Thanks. The blade is still factory fresh. It will shave hair on my forearm w/ a little work, just not as easily as my Spyderco will. So I was thinking of making it Spydie scary sharp.

You bring up a good point. Being there is a fairly decent edge on it already, what grit should the first pass be?

This knife has a slightly curved clip point. I'm not sure how to sharpen it as the EdgePro stones may be too wide. I guess I won't know till I try.

I also don't know how hard to press down on the EdgePro. On my practice knives a fairly light touch seemed natural.

BTW, I don't think I've got a steady enough hand to hand bevel anything.
 
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