• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.
  • Some users may still have issues remaining logged into the forum. Please delete old bookmarks. If you are still having issues, go to the Site Issues forum here and let us know EXACTLY what you clicked on before the login issue arose, so we can try to track it down. We are working on this, and appreciate your patience. Thank you.

[4]

Testing Hardness

January Project of the Month [3]
[10] Like what you see?
Click here to donate to this forum and upgrade your account!

wawoodman

himself, himself
H-M Supporter-Premium Member
Joined
Mar 19, 2011
Messages
920
Likes
689
#1
I'm about to try hardening some small parts with cherry red and a torch, since I don't think I can do the furnace thing. So after I'm done, I would like to check the hardness.

I certainly am not going to go for a Rockwell tester. I saw these on the Bay: http://www.ebay.com/itm/TSUBOSAN-Ha...986884?hash=item3600c29804:g:w78AAOSwo3pWgobw

Has anyone used them?

On the other hand, do I need them at all? Will a simple file tell me (more or less) all I have to know?

Happy new year, y'all!
 

4gsr

HM Shop Superintendent
Staff member
H-M Supporter - Sustaining Member
Joined
Aug 8, 2011
Messages
4,847
Likes
3,126
#2
They work! As long as you don't use them as a saw as I've seen in my past. Just work with the hardest one first. If it cuts, go down one hardness and try again. Chances are it will be hard. But what you have to watch for is, sometimes the surface will be soft for a few thousandths deep. This is called carbon diffusion of the surface when heated in open air. But with a acetylene torch the carbon given off will create an carbon atmosphere around your part as long as the flame is present.

Oh, you can use a file, but if the file is harder than your part it will cut. Some files can be up to around 65-67 HRC. But the heat treat files work quite good. I have a set I snagged off of eBay years back here some where. Where did I put them?
 

bfd

H-M Supporter - Premium Member
H-M Supporter-Premium Member
Joined
Sep 9, 2016
Messages
373
Likes
208
#4
I saw somewhere in toolland a set of files for hardness testing these files had a range if hardnesses and if it cut the metal then the metal is not that hard. b ut maybe I'm just dreaming bill
 

BGHansen

H-M Supporter - Premium Member
H-M Supporter-Premium Member
Joined
Nov 23, 2014
Messages
792
Likes
1,895
#5
Grizzly has(had?) them for around $60. I recall picking a set up off eBay (new) for around $40. I've never used them so can't speak to their (or my) accuracy. I didn't find them on Grizzly's web site, here's a typical eBay listing for similar files.

Bruce

upload_2017-1-5_15-1-15.png
 

4gsr

HM Shop Superintendent
Staff member
H-M Supporter - Sustaining Member
Joined
Aug 8, 2011
Messages
4,847
Likes
3,126
#6
You can test them against a couple of Wilson hardness test blocks or with something with a known hardness. You won't get it down very close, but within +/-5 Rockwell points on the C scale.
 

chips&more

Active User
Active Member
Joined
Mar 19, 2014
Messages
2,168
Likes
1,515
#7
Never tried the files? I do have an Ames hardness tester (pic). Works great! Only drawback is it’s limited to the size of your test samples. But I have not had that problem yet. The only problem I have had is I can’t remember how to use it. It has a certain order of things to do when using it. And I can never remember them! So I have to look at the instructions each time I use it!...Dave
rctester.jpg
 

Hawkeye

Active User
H-M Supporter-Premium Member
Joined
Jun 17, 2011
Messages
1,789
Likes
463
#8
I just got a set of those same ones a couple of weeks ago. Surprised me on a few things I had assumed were harder. I'm glad I got them.
 
[6]
[5] [7]