pencil testing question

[twc1964]

Ok, i know there's a sticky on this but i really did not find what I'm looking for. I've got the correct pencils so when i test whst reaction sm i looking for? will it be a peeling of the lead? also, do i just hold the pencil upright and scrstch? hmmm

[bangerjim]

The thread on pencil test explains it. Test has been used of decades by the paint industry.

You pull the pencil lead across the sample like you are writing. If it digs in or leaves a mark, sample is softer than pencil.......go to next softer pencil. If no mark or indent, sample is harder than pencil lead.....go to next hardness pencil and do it all over again. When you find a pencil that barely leaves a indent or mark, that is the range of hardness.

You DID get the chart of pencils vs. hardness, right?

There are so many outside variables in this method it is not really that accurate.

It is nothing more than a SWAG, but it will get you in the ballpark on hardness. And that is what you are after.

bangerjim

[RogerDat]

As the sticky states - pencil point sanded off so the lead is a cylinder. Hold at 45 degree angle with edge of cylinder shaped point against lead.

[twc1964]

Ok guys, read it again and found the info. finished testing my ingots and a batch of ingots i bought from retired navy. those little ingots are really hard! test says mono. they ring when u tap em on a hard surface. guess i now know how to harden some of my soft stuff lol