Thread: Is It Necessary To Use Figure 8's When Lapping?

When using a DMT 325 to lap or clean a Naniwa SS, is it necessary to use figure 8's, or will a back and forth motion work as well?

I use all of them but always end with the 8's also you want to spin the target Stone/Hone occasionally, that whole objective is eveness so the more rotations and pattern changes you do, the more likely you will get a nice smooth even result IME

Unless you are applying precise and even pressure throughout your lapping process, it is a great idea to do what Glen mentioned. Spinning the stone as well as a combination of 'strokes', circles in both directions, ups and downs, lefts and rights, ending with figure 8's will give the best result without giving yourself carpal tunnel syndrome.

My handidness dictates that I can use all types of strokes on lapping but figure 8? No my brain doesn't do figure 8's But I do reverse the stone a lot and do mostly ovals and circles. works great for me any way. IMHO only!!

tinkersd

When you lap anything,be it stones,lathe bits,all cutting tools,A Figure 8 pattern should always be used,is a standard used by all machinists.
The idea being, even if the lapping plate is not 100% flat,you will get a 100% coverage

I just did my first lapping yesterday and wondered the same thing. On the norton 4k, 8's were ok and easy. On the 8k 8's were difficult to keep going. I did 8's, back and forth, and circles. I figure if you mix it up and do a bunch a different methods it will be fine.

Yeah, I think the thing is to make sure that you're not just repeating the same pattern over and over as that will exaggerate any unevenness in pressure. By mixing it up, your odds of getting an evenly flattened surface should be pretty good.

lots of great input here from trustworthy members!! I am happy someone asked this question because it was always in the back of my mind as well. thanks for the info everyone!

One thing to remember which has kind of been mentioned already is even pressure. Long strokes off the end of the stone can promote uneven pressure unless you have an educated hand. My habit is to use very short strokes regardless of pattern when using a diamond plate but YMMV as usual.

Some diamond plates will also bend slightly, if you want to be sure to get your hone flat put the diamond plate om a flat surface and your stone on top.