Got a CT lead tester. Weird results. Child proof dial indicator?

[Adam10mm]

Let me say I am not mechanically inclined. I know how to read a micrometer and that's it. Worked in a steel mill making steel bars to various diameters.

Got my CT tester today. Got it set up correctly. Tried a few bullets that were 50/50 lino/WW. The lino was known lino, the WW were clipons melted by me.

I got the dial indicator installed like the directions say with about .250" of takeup in the indicator pin. The little dial shows about halfway between 2 and 3 and the big dial shows 50. Then I turned the face to put the zero on the big needle position.

The directions say to put a bullet in, let's call it the bullet area, and turn the screw in until it just touches the bullet. I take this to mean the point at which you can let go of the bullet and it is suspended by the tester.

Then mark where the dial is and turn the screw ONE FULL TURN. The difference between the readings on either side of the full turn is then applied to the chart included and gives a BHN approximation.

Simple enough. Wrong. After the one full turn the big indicator needle move a full revolution or .100". This indicates to me, according to the chart, that the BHN is 32+. I've read that cutting lino with WW should lower the BHN, not increase it.

Am I doing this right? I'm pretty sure I'm reading the dial right. I tested about 8 boolits and got the same results.

[MT Gianni]

Try a couple of Ingots. If CT is casting tree then try reverseing it and test with the point on the nose of the bullet. Try it from the point at which the bullet is firmly suspended in the tester and it will not turn. What is important is doing the same thing every time when you are getting a reading.
When your test matchs a known alloy such as pure lead or pure lino with the estimated hardness on the sheet then your starting tension is the same as the test sheets starting tension. I've never hit 100 with oven quenched on mine. Gianni

[Adam10mm]

I tried a few with the nose both ways, on the pointer and on the flat.

I'll try some more stuff. I have unmelted WW and pure lead pipe I'll try later.

[mtgrs737]

I think what you may be doing wrong is in the set-up of the indicator. When setting the indicator you need to set the 1/4" of travel and then re-set the indicator dial to "0". You are now ready to make your first test. Put the alloy in the tester until it just touches the screw point and then note the pointer position on the screw and give it one full turn in, then read the dial and use the conversion sheet for BHN. Mine works great this way.

[Whaump 'em]

Some wheel weight alloy can be an eye opener, did you water drop those bullets?

[dubber123]

Some wheel weight alloy can be an eye opener, did you water drop those bullets?

Yep, I have gotten up to 30 with simple water dropping. Supposedly oven heat treating can get WW's even higher.

[Adam10mm]

I think what you may be doing wrong is in the set-up of the indicator. When setting the indicator you need to set the 1/4" of travel and then re-set the indicator dial to "0". You are now ready to make your first test. Put the alloy in the tester until it just touches the screw point and then note the pointer position on the screw and give it one full turn in, then read the dial and use the conversion sheet for BHN. Mine works great this way.

I put the indicator on the rod and slid it in until it showed .250" of travel and locked it in. Then I loosened the screw that holds the face and turned the dial so that the needle lined up with the zero on the face. This zeroed out the dial indicator, just as the directions said to.

I did everything you said and still get .100" of travel after one full turn.

I tried to test a raw WW but it was too skinny to get a reading. I tested two air cooled known WW boolits and they did about .083" or about Lyman # 2 hardness. I tested two boolits both nose first and nose away from the pointer and they tested in the .083-.085" window, indicating about Lyman #2 (15BHN) hardness. These have been cast and sitting for over a month.

[38 Super Auto]

I'd also suggest that you check to verify the shaft on the dial indicator and the large spring loaded bolt are lined up.

mtgrs737 makes a good point: make sure the dial indicator is zeroed before you start. The dial moves and can be locked down at zero.

I get very repeatible results on the order of 1 or 2 mils

[Lloyd Smale]

What i do with all my testing Is when i set the bullet in the tester i tighten down the screw untill the dial moves .002 then zero it out. that way i have a very consistant start. If you start the full turn of the crank with a differnt starting pressure evey time you will never get consistant readings. i also long ago threw my chart away. I use the tester to compare my alloys rather then to put a number on them. Even if wws read a 100 i wouldnt care as long as lineotype read 120 ect. It it really bothers you the tester is capable of being calibrated by increasing or decreasing spring tension

[Bret4207]

I do mine just like Lloyd. I was also surprised at the hardness of my "soft" alloy. Try testing fresh cast and then the same sample 2 weeks later. That'll be an eye opener!

[Adam10mm]

Good point Lloyd. I'll have to try that.

[Gussy]

I tested two air cooled known WW boolits and they did about .083" or about Lyman # 2 hardness. I tested two boolits both nose first and nose away from the pointer and they tested in the .083-.085" window, indicating about Lyman #2 (15BHN) hardness. These have been cast and sitting for over a month.


These readings are exactly as they should be (this is one of the alloys used to set the tester up and those are the readings I set it to). I have no idea why your other material reading is odd. I would suggest other alloys be tested and if they are correct, then the mystery alloy may be the problem and not what you thought.
Gus.

[Adam10mm]

Sounds good. I have limited casting time right now but will test other alloys.

[VTDW]

I haven't had any problems using the supplied directions with the CT tester. One thing puzzles me though. The supplied chart doesn't go past 23 Bnh does it? The owner of CT told us in a thread here that he he didn't give info in the chart past 23 Bnh because he doesn't have any. I have a good friend that is sending me a few that read 30 Bnh on his Lee tester so I can take a reading and will know what the CT indicator says in order to read higher Bnh readings with confidence.

Thanks,

Dave

[Adam10mm]

Dial=BHN=alloy

.015-.035=5 Lead
.045-.050=8.5
.053-.056=9 30:1
.062-.065=9.5
.068-.070=10 20:1
.072-.074=11.5 10:1
.074-.076=12.5 new WW
.080-.085=14 1yo WW
.084-.086=15 Lyman #2
.086-.090=22 Linotype
.090-.093=23-25 quenched WW
.093-.095=27-28 mono/stereo
.098+=32+ heat treat

That's what is on my sheet.

[VTDW]

Thanks for going to the trouble to give us the info on your sheet. I am going to make myself a new one right now for sure.

Thanks again and the beer is on me.:drinks:

Dave