Trouble sharpening M4 on Sharpmaker

R

rc51kid

Joined
Dec 7, 2009
Messages
170
I amnusing a Sharpmaker MK2 to try to sharpen mt M4 Bugout and having a little trouble. I can get a ok edge on it but i feel like i am just working it a lot and not getting the edge i would expect. It was reasonable sharp when i started. No damage or anything.

I did my wifes Benchmade 530 in S30V. A few passes of each grit left a fine bur each side with each grit.Very fine. After the fine grit i stropped it a bit and it is razor sharp. Took about 5 min total. Maybe 3 passes with each grit.i just cant get the same results with the M4. Also the blade shape on the Bugout has more belly to it. So maybe that is making it harder?

Any advice?
 
Yeah, for anything with 3% or more vanadium, the ceramic rods of the SM will struggle to fully refine the carbides at the apex. Diamond (or CBN) makes a whole world of difference with steels like these. Results on an already fully apexed & refined edge can look pretty good at first, after a few passes on ceramic. But over time, continued use of only the ceramic will tend to burnish the edge more than refine it, and the edge will become rounded and slick. Then cutting performance will noticeably degrade.

For simple burr removal after the edge is fully apexed and refined, a few very light passes on the ceramic rods can do OK with these steels. Otherwise, stick with diamond or CBN for the best results.
 
Last edited:
The Sharpmaker is an ok tool, not something I would recommend for actual sharpening though. Very small stones and the ceramic abrasive is rather slow. You are also limited to how much pressure can be applied which slows the process considerably. As stated, M4 is a very wear resistant and hard steel.

Another limiting factor is the factory edge. Most put way too much stock in a factory edge when in reality most factory edges are pretty bad. Put that edge on a wide flat stone at a consistent angle and you will likely find more high/low spots and inconsistent angles than the rocky mountains.
 
Jason B. said:
The Sharpmaker is an ok tool, not something I would recommend for actual sharpening though. Very small stones and the ceramic abrasive is rather slow. You are also limited to how much pressure can be applied which slows the process considerably. As stated, M4 is a very wear resistant and hard steel.
Click to expand...
Yeah, it will help maintain and edge but to actual do serious sharpening it's not the right tool for the job.
 
Just a FYI, based on my recent experience learning how to sharpen 15v on diamond plates. It seems that the DMT plates I started using left a really toothy edge, even the extra fine plate. Give the plates some time to break-in, for lack of a better term. I was actually going to go back S30v blade steel in the same knife model because of my trouble with 15v. Now that the plates are broken in and I use a “VERY LIGHT” touch when I am sharpening on diamond plates; now I am getting very good results. There was definitely a learning curve for me going to diamond plates and a super steel.
Good luck and don’t give up.
 
You must log in or register to reply here.
Back
Top