Thread: Thumb test

Hi all,

Could someone describe to me exactly what the "thumb test" is? I did search the forum titles and did not get any results. From the bits and pieces of it being mentioned I am assuming that it is a cutting or slicing movement on the skin of ones thumbprint? (very slight I hope) This being done to feel the edge dig in? Or am I way off here . . .

Emil

Ever so very gingerly draw yuour thumb across (NOT along) the edge and slightly downward and you will feel the cutting fins tickle the pas of your thumb. When it does, it's time to move on to the Hanging Hair test.

X

Originally Posted by xman

Ever so very gingerly draw yuour thumb across (NOT along) the edge and slightly downward and you will feel the cutting fins tickle the pas of your thumb. When it does, it's time to move on to the Hanging Hair test.

X

If you have any neuropathy in your fingers...DON'T do this test.

RT

I thought you "drew the edge over a moistened thumb nail". I'm assuming that means drawing the edge across your thumb nail, as if you were trying to cut it in half perpedicular to the thumb bone.
If it passes it should dig in smoothly? Feeling rough is no good, sticking is no good?
Is this right?

I don't really know much about thumb tests so forgive me, my personal experience is limited. There is a thumb nail test and a thumb test. One inspects the edge quality and the other the sharpness of the blade. Running the blade on an angled thumb nail lets you feel for "dig" and smooth movement, skipping and rough spots are bad. With experience the moistened thumb can detect the sharpness of a blade which has been stropped. Never do the thumbnail test after stropping.

All of this predisposes that you have access at some point to a sharp, well honed razor as a comparitive baseline. Which, given the point of the test is usually absent in the first place.

The thumb test is where you draw your thumb across the blade perpendicular not parallel to it. Running it parallel is dangerous as you may cut yourself. If the blade is sharpe you will feel it really dig in and it feels like it is scratching your skin. A dull blade will not do this. It is really hard to tell someone how it feels until you do it with a sharp blade. Some even wet their thumb and do it this way. If the blade is really sharp it will dig in this way also. I however use my forefinger I seem to have a better feel of things with it than I do with my thumb. It is ones own preference. The fingernail test, on the other hand, which is drawing the edge across the nail very lightly is excellent for telling if a blade has nicks or has a burr or is generally rough. You can also tell to some degree if it is sharp if it digs in somewhat and runs across smooth. Also just letting the edge rest on the nail at an angle one can tell if the blade is sharp as it will not slip off it but will dig in. Also as was mentioned earlier do not do the fingernail test after stropping because the very very thin fin can be ruined.

I really don't understand all the "thumb test" stuff. I tried it a few times and there is no way a thumb is sharp enough to shave with. Even the nail after being freshly clipped is not all that sharp.

I will stick to testing my razor instead and getting it shave ready <g>.


(sorry, I couldn't resist)

Tony

The Thumb Nail Test is done to a water wetted thumnail, across the back of the nail. That test is done in a parallel or cutting fashion, unlike the Thumb Test. You're supposed to feel it digging in to the nail as it cuts along. I find it a very uncomfortable test where I can't quite detect the same level of subtlety as with the Thumb Test so I don't really use it. The only information it gives me is in detecting the sevrity of nicks in a blade.

X

For the life of me I can't feel anything with the thumb test. I must be doing it wrong. I know not parallel to the edge but are we saying draw your thumb from the spine to the edge or from the edge towards the spine?


As for the thumb nail test I don't use it

Rich,
Neither, your thumb/forefinger is raked across only the edge with a slight downward angle. This way if the edge is sharp it will dig into the skin with kind of a scratchy feeling. The sharper the edge the more it will dig into the skin. Try it with a dull razor and then with a sharp razor and you can tell what I am talking about. Of course the real test is shaving with the razor, this only gives you a clue what you are doing with the edge while you are honing it. Some, after getting it to drag really well on your thumb, will do the hanging hair test. My hair, I guess, is so light that I rarely get it to cut because it moves out of the way of the edge so easily that it won't cut.

Hope this helps,