Thread: Is this the correct DMT 325 for lapping?

Thank you, I've got it ordered now. I think its time for some pencil grid lines!

it has been recommended to me to have a lapping plate equal or greater in size then the stone you are lapping, maybe for convenience rather than necessity. they make 10x4 lapping plates and most bench stones are no bigger than 8x3. most people settle on the 8x3 plate. if someone has had good success using a smaller plate on a larger stone id love to hear about it, and how do you check if its flat after you are done lapping?

Originally Posted by KillerDr3w

Hi,

I've spotted a rather cheap DMT 325 which I think I'm going to pick up for lapping a set of Naniwa Superstones. Before I buy it, can someone just confirm that this sounds like the right product:

DMT Diamond Whetstone 150mm Plastic Case Blue 325 Grit Coarse
PTDDMTW6CP

Thanks!

kD

I like my 325 grit plate that is 4" X 10" or 101.6mm X 254mm. Mine was like $ 80 US but it saves me tons of time

Originally Posted by Birnando

That is the one I have, and indeed the one most referenced on here as the ideal lapping plate.

When I got mine I didn't even consider getting a lapping plate the same size as the stones I had (3" X 8"). I automatically went 4"X10" and I find it easy to work with. This makes me think now I could've saved myself some money as either plate achieves the same result >.< I think I'd still prefer the 4X10 though.

Originally Posted by ezpz

it has been recommended to me to have a lapping plate equal or greater in size then the stone you are lapping, maybe for convenience rather than necessity. they make 10x4 lapping plates and most bench stones are no bigger than 8x3. most people settle on the 8x3 plate. if someone has had good success using a smaller plate on a larger stone id love to hear about it, and how do you check if its flat after you are done lapping?

If you work the surface even with a bit smaller of a known flat surface like a DMT, the current flat area will hold it flat. All bets are off if you just rub along one edge though lol. you can also do the pencil line thing one last time, and confirm a little bit of even working makes them all disappear nearly at the same time (depending on how you work the stone of course) A big flat plate does make it nice and easy, no worries style, until you feel the suction.

Originally Posted by LameBMX

If you work the surface even with a bit smaller of a known flat surface like a DMT, the current flat area will hold it flat. All bets are off if you just rub along one edge though lol. you can also do the pencil line thing one last time, and confirm a little bit of even working makes them all disappear nearly at the same time (depending on how you work the stone of course) A big flat plate does make it nice and easy, no worries style, until you feel the suction.

Good call.

I think the DMT plates 'break in' with time(not sure what that means but will see I hope as I use mine more). When I first got mine it had a high spot where the diamonds were higher than the rest and I could see scratches in my stones when I was finished. Glen(gssixgun) suggested I take like a screwdriver that was longer than the plate, lay it flat on the plate and run it along to knock down that high spot. I did and it worked like a charm! Thanks again Glen!

When finishing a lapping I use just the pressure of the weight of the stone on the plate(I do mine kinda backwards from how I've seen it in vids where the plate is on top of the stone and I hope this doesn't matter. I can't see why it would but I'm not right all the time). So my hand is just guiding the stone without any downwards force. The diamond plate removes material by scratching it off but in the final process to finish it up I don't want the scratches to be deep thus giving a better surface to hone on. Also, I think I ran into a bit of a break in where maybe a few pieces of diamond broke off and I used too much pressure once and it embedded into the stone and when I honed, I felt it through blade feedback. It was pretty obvious. It lapped out no problem though.

First thing I did with them was putting a khukri to them. It had nicks from putting it blade on blade with a sword, I am sure that would have broke them all in.

You bit of diamond breaking off is why I will probably never try the triangle steps on honing. That just seems like way too much cleaning to make sure the larger grits dont wander into the finer grits. If 1 particle makes the jump, your blade finds it lol.

I have the 6 x 2 DMT. It's made of steel. I find it works good, but I wish I had bought the larger 8" one. I use magnets on the back to use as hand holds, as I don't have a stand to fit it.

Originally Posted by Blberger

quick question: what is the D8C in non abbreviated words so I can look it up on SRD?

Where do I go to learn about all this shtuff? Straightening hones, breaking in hones, etc? Im a virgin to the hone side of things.. Point me in the right direction, wouldya?

XXC Extra Extra Course
XC Extra Course
C Course
F Fine
EF Extra Fine
EEF Extra Extra Fine

The real stats are on their homepage.

D general shorthand for Diasharps, afaik.

The 8 is the plate size, as in 8 Inches.

I got a 2 double sided plate kit, D6XC & D6C and a D6F & D6EF, and my D8EEF I am just missing a D8XXC.

each 6" plate of the kit has 2 grits, eXtra Course & Course. The other has Fine & Extra Fine. The Extra Extra Fine is only available as a 8" single sided plate.

Hope that helps with the vernacular. Visit their website for more information.

Originally Posted by mjsorkin

Many people here use the D8C. It's a 200mm length diamond plate with an uninterrupted surface.

So is the DMT D8C the same thing as the DMT 325?

Or is the D8C the preferred version of the 325?

325 seems to be the grit.

I believe the D stands for their Dia Sharp series, the 8 refers to the size (8X3) and the C refers to the grit of 325. You can get smaller and larger plates in that series too. Info here DMT DiaSharp Bench Stone Models | DMT® - Diamond Machining Technology . Personally I wanted a plate larger than my Naniwas for lapping them so went with the D10C plate. Yea, there is quite a bit of confusion as most everyone refers to the grit, 325, not the size of the plate.

Bob