Hapstone Premium CBN back plate for Kadet pro stone holder?

huntyukon · Jan 17, 2024

Hey folks,

I’m thinking about trying the Hapstone Premium CBN stones. Mainly as a more cost effective alternative to Venev metallic or Poltova. It looks like those stones still have the square ended backing plate. The stone holder of my Kadet pro already has the groove on one side, so that any EP form factor stones fit really well. Would the square ended stones still connect as securely?
I understand that “back in the day” all the Tsprof models fit those better, but as securely as the new upgraded version holder?

Thanks for letting me pick your brains again, guys.

Mr.Wizard · Jan 17, 2024

I am seeing beveled ends on the Hapstone USA product page.

Another Shepherd · Jan 17, 2024

Hapstone CBN stones, both regular and premium, work on TSProf sharpeners.

TSProf stones fit Hapstone sharpeners, but the TSProf stones are too thin to work well with the Hapstone stone holders.

huntyukon · Jan 17, 2024

Thanks so much for clearing that up, guys. Do any of you have experience with them?

Another Shepherd · Jan 17, 2024

huntyukon said:
Do any of you have experience with them?

I do not have lots of identical blades to do controlled testing with, but my impressions are that Hapstone Premium CBNs are excellent for mirror polishing, Poltava CBNs are excellent for reprofiling, and TSProf diamonds are somewhere in the middle. I have not used Venev because of the somewhat higher maintenance that is recommended for them.

I hope that one of these days, 777 Edge will show up and offer his opinions.

DeadboxHero · Jan 17, 2024

Another Shepherd said:
I do not have lots of identical blades to do controlled testing with, but my impressions are that Hapstone Premium CBNs are excellent for mirror polishing, Poltava CBNs are excellent for reprofiling, and TSProf diamonds are somewhere in the middle. I have not used Venev because of the somewhat higher maintenance that is recommended for them.

I hope that one of these days, 777 Edge will show up and offer his opinions.

The Hapstone premium cBN and the Poltava metallic bonded cBN are the same.

They are both metallic bonded.

They are both made in Ukraine.

They are both made by Poltava.

Another Shepherd · Jan 18, 2024

DeadboxHero said:
The Hapstone premium cBN and the Poltava metallic bonded cBN are the same.

They are both metallic bonded.

They are both made in Ukraine.

They are both made by Poltava.

They look different. The Hapstones are shinier.
They feel different. The Hapstones are smoother.
They sound different. The Hapstones are quieter.
A Poltava premium CBN 120 cuts faster than a Hapstone premium CBN 120, 80, or 50.
The Poltava premium CBN stones are 2mm thick, not counting the backing plate.
The Hapstone premium CBN stones are 3mm thick, not counting the backing plate.

Gritomatic descriptions:
Poltava "Metal bonded CBN stones utilize copper-tin alloy bonding for high endurance and low wearing rate.
Hapstone "Premium CBN utilizes advanced hybrid metal-organic binder - composite of traditional copper-tin alloy and polymer components."

DeadboxHero · Jan 18, 2024

Another Shepherd said:
They look different.
They feel different.
They sound different.

How the stones are dressed makes a big difference.

Another Shepherd said:
A Poltava premium CBN 120 cuts faster than a Hapstone premium CBN 50.

That's true even if you use a Hapstone Premium cBN 150 and a Poltava Metallic bonded 50.

There's more going on then meets the eye.

Another Shepherd said:
Gritomatic descriptions:
Poltava "Metal bonded CBN stones utilize copper-tin alloy bonding for high endurance and low wearing rate.
Hapstone "Premium CBN utilizes advanced hybrid metal-organic binder - composite of traditional copper-tin alloy and polymer components."

The scratch pattern and function are the same along with the maintenance and dressing.

DeadboxHero · Jan 18, 2024

Stones under 300x magnification

https://imgur.com/uFgY3eS

Hapstone Premium cBN 100/80um

https://imgur.com/6ydAxVJ

Poltava Metallic bonded cBN 125/100um

Mr.Wizard · Jan 18, 2024

DeadboxHero said:
That's true even if you use a Hapstone Premium cBN 150 and a Poltava Metallic bonded 50.

There's more going on then meets the eye.

You mean the #150 is faster? Studies I have read show a point below which coarser is no faster, or only very slightly faster, but I do not recall one where the speed actually reversed. This sounds like a problem with the #50 stones.

DeadboxHero · Jan 18, 2024

Mr.Wizard said:
You mean the #150 is faster? Studies I have read show a point below which coarser is no faster, or only very slightly faster, but I do not recall one where the speed actually reversed. This sounds like a problem with the #50 stones.

Paul,
That is correct for sharpening stones, it seems to be 125-80um (~100-150grit) is the cut off.

Anything coarser seems to be slower for hand powered sharpening.

It's not just the size of the abrasive but also the abrasive volume and the sharpness of the abrasive grains that factor in for the cutting speed performance.

We don't generate the force and speed required to fracture the larger grains to "self sharpen" them in use for proper function. You'll even notice this as the stone will slide rather than cut in comparison.