Thread: Lapper Micron Tolerance

It's time for a new lapping plate and I'm at a crossroad. The common $50 lapping plates work, but I've been thinking about stepping up. One of the $380 models boast a +/- 5 micron diamond size tolerance. I spoke to a dealer who said that the surface of your stones is only as uniform and flat as the lapper. Meaning that if the size of the diamonds in the lapper varies more than of my lapper, I'm not taking advantage of the stone I paid for. So, we get down to microns, which is a problem for me, and here's why:

If I was sharpening completely flat blades, I'd be pulling/pushing them flat all the way up through the progressions, and a perfectly flat and uniform surface would be ideal. But I'm not, I'm often sharpening slightly rounded blades (smiles, etc) with a X or rolling-X pattern. With this in mind, just how flat and uniform do my stones really need to be?

I know that uniform flatness is very important when grinding and setting bevels, but when you get up to 10-20k, and start rolling, everything changes. Whats your opinion?

I am in the camp that would rather pay a little more up front. I agree that when you start getting into honing gymnastics that you end up weighing aspect of a hone differently. However, with a good quality lapping plate, you NEVER have to worry about your hones being flat. Eliminating that variable is huge IMO.

I think the more inexperienced you are the bigger deal it is (guess that's why I prefer it )

It's nice to have dead flat stones, but then again, you don't really need them. If you want simplicity and consistency, spent the money. But I've honed razors on stones out of the box, just to see, and been totally fine.

A DMT is plenty flat for me.

Lapping a stone “dead, perfectly” flat is not necessary, smooth is more important. The flatter the stone is, you will use more grit per pass but not necessarily get a “better” bevel or edge.

If the stone is not dead flat, but still smooth the razor will ride on the high spots using less grit, but will still provide a smooth flat bevel and edge.

Paying almost 400 for a lapping plate is over kill that will not provide better result on the edge of the razor. I would rather spend that money in quality finishing stones.

The DMT D8C is hard to beat and has been the gold standard for many homers for a long time. A DMT for most is a lifetime purchase.

A flatter lapping plate will not make a flatter, keener edge. If absolute flatness was critical… strops would have to be perfectly flat also.

What they said

with my rockhounding I lap a lot of hones. I use the 4x10 DMT plates. I have the dia-flat and the 325 that seem to work hard and do a great job. I can't help but be curious what a $380 lapping plate would be.

Originally Posted by Tallm

It's time for a new lapping plate and I'm at a crossroad. The common $50 lapping plates work, but I've been thinking about stepping up. One of the $380 models boast a +/- 5 micron diamond size tolerance. I spoke to a dealer who said that the surface of your stones is only as uniform and flat as the lapper. Meaning that if the size of the diamonds in the lapper varies more than of my lapper, I'm not taking advantage of the stone I paid for. So, we get down to microns,

Sounds like a load of sales bilge to me, they want to sell you $400 lapping plate I am sure they are very good but in real world practical use I honestly don't see what the benefit would be over a DMT costing far less.

As to the tolerance in particle size of a lapping plate, within reason how does it make a difference. It's more important that it's flat

I guess it's upto you but ask yourself if you are going to be able to tell the difference between one lapped on a DMT and one lapped on one that has a +-5 micron particles tolerance ?

I have used the Atoma plates for almost 5 years now and I highly recommend them, they have way less suction than the DMT and the scratches left from the #600 are really fine. You can adjust to make a smoother finish on your stone if you allow the slurry to remain for the final few laps. For polishing my stones and for slurry generation I have worn out #600 Atoma's and these leave my stones with almost invisable scratches. The Atoma cost more than the DMT but the product is better and the base plates are thicker but do not weigh so much because they are milled aluminum and not steel like the DMT.

good luck

Alx

Originally Posted by JimmyWetshaver

Honestly I think you would be very disappointed spending all that money for what I dont not think would afford you any appreciable difference. That is, of course, just my opinion on the matter.

I say this is the best of spirit, but that same statement could be said about pretty much any part of this hobby. As you point out, though, it's different things for different people.

There is a place for tight tolerance lapping plates in the biological research field, but for shaving I think it is a bit of an overkill. Both the DMT and Atoma have worked fine for me for years.