Brass annealing hardness - scratch test?

[Zeneffect]

I got around to replacing my induction wand with another unit (supposedly 100w stronger, quick disconnect for coils, faster fans, same fan on/off issue as previous version)

Long story short, I have gone through the testing process and everything is setup. What i don't know is a numerical value associated with parts of the brass.

I dont have $1000 for the ames hand held unit. A leeb tester is not appropriate for such thin walls. I don't have the money for an ultrasonic either so I have been thinking about this and options for sub $100 are limited to DIY exclusively. A webster w-20b is $279 from China. Leeb with DL probe is about the same cost.

I had thoughts about making an indenter and measuring intention width with a loupe while using virgin lapua brass as a control group....

This lead me to https://matweb.com/search/PropertySearch.aspx

Materials database which I can search materials by properties. This got me to thinking... is a scratch test possible?

Since AMP documented vickers hardness of fresh, work hardened, and re-annealed, we know the appropriate hardness range to target in the search... basically 100-140.

Shouldn't I be able to make a scratch test based on the database? I see some stuff I know I have laying around in the garage like 6061, oxygen free pure copper, etc.

[Zeneffect]

Looking into what the cost of appropriate load cell costs... I have an arbor press. Diamond indenter is $30.. I have a loupe with scale. Hmm. Might get scientific about this.

[grayfox]

Seems it would be hard to beat the approach of getting the brass to the right temperature range, then pull the heat off. Annealing's biggest and easiest determinant is temperature... like using the tempilac sticks/paste.
The guy who made the timer/induction wand setup seems like the most straightforward approach.
I have all the parts but haven't gotten around to setting it all up.
So I guess admittedly I'm speaking without any field experience. there is that...

[Zeneffect]

Im focusing on the end result to ensure the time is correct. I need to devise a way to measure... so far the bill of materials in every iteration of making a repeatable test with solid results equals or exceeds a webster w-20b. I might just bite the bullet so to speak and eat the cost. It will be worth it I think.. usually when I find that I can measure, I can get better results in the long run. Having tooling to measure will allow me to optimize coil structure, annealing time, etc.

*edit*

ordered a w-20b. turns out... you can save a few bucks by understanding that Webster can also be pronounced "Wechsler" and some sellers might sell it under that name. $212 shipped... all just to test how hard brass is. Given the discount, once i'm set I'll split up the cost with a couple of local reloading buddies.

FYI... ordered the chineseum version. For intents and purposes so long as the scale works, and is repeatable thats all that really matters. it doesnt need to correlate with any real vickers or rockewell numbers... it just needs to spit out a value for virgin brass that can be used as a baseline.

[jasper2408]

ordered a w-20b.

You needed the W-20. The 20b has an opening size of 8mm from the probe to the rod which is too far and won't touch the brass as the neck metal is not thick enough. I ordered the w-20 which has 6mm for the opening size and then had to grind the 10mm rod down on 3 sides to fit my 223 cases. The fellow that I got the idea from on Utube had to grind down the rod also.

The first Starline necks I tested were 13 new and once I resized them or turned them they went to 17. To get the fired case neck back to 12 took 3.6sec on my Benchsource annealer using both torches.

I got the below chart off Amazon so you can see the different opening sizes on each tester.

https://

[Klem]

Not trying to be silly but if you're going to that much effort to investigate proxies for end results, you could just determine the best induction settings by the end result itself.

Separate a few batches of cases and see which temp gives you the most reloads, and/or smallest groups.

[Zeneffect]

Not trying to be silly but if you're going to that much effort to investigate proxies for end results, you could just determine the best induction settings by the end result itself.

Separate a few batches of cases and see which temp gives you the most reloads, and/or smallest groups.

I have noticed some variability due to environmental factors. Though the end goal is to increase accuracy and extend brass life I'd rather determine the annealing by a repeatable hardness value then track times by ambient temps (which can range from 40f to 110f) cold days require more time obviously... I could probably mitigate this by switching to a plastic loading tray as it won't act like a giant cold heat sink like my aluminum one does.... then again it won't act like a giant aluminum heat sink and I'll have to change the time anyways... which means I'd have to figure out the timing again.. and my method is a pain in the @$$ using 120fps video capture (to determine time to silver flash)

Regarding w-20 vs w-20b



Notice the minimum dimension of .6mm is maintained with both. Anvil size changes otherwise same unit. Calibration requires pressing the probe into the anvil and adjusting the scale to 20, so dimensionally it has to work otherwise it would be impossible to calibrate.

Same mods will need to be done. Need to clearence the plunger/indenter. Need to grind down anvil on 3 sides if I want to use it for 5.56 (though far less... .25 left and right, .5mm bottom is 10 min of hand work with a file)

Current anneal time for lapua brass is 1.52s in 60-70f using induction. 6 coils, about 2mm air gap between case and coils.

[jasper2408]

All of the Chinese W models come with a hardened metal sleeve that fits over the anvil so that you can use that to calibrate to save the anvil from damage, even though you can use the anvil to calibrate on the w-20, which is only 6mm in the opening. I think the w-20a comes with a sleeve also but not sure.

On the w-20 and w-20b they use the same indenter cylinder housing length so on the 20b, with the longer 8mm spacing in the opening, the indenter isn't long enough and will not touch the anvil without the calibration sleeve slipped over the anvil. It will test .6 thick metal without the sleeve but not be long enough and come down far enough down to test case necks as they are not => .6. That is why it won't work.

I hope you are lucky and get a brand that uses the bare anvil to calibrate on the w-20b then you will be good to go.

I saw this info on a video but I can't find it now or I would post it.

This why I bought the w-20 instead of the w-20b.

[Zeneffect]

All of the Chinese W models come with a hardened metal sleeve that fits over the anvil so that you can use that to calibrate to save the anvil from damage, even though you can use the anvil to calibrate on the w-20, which is only 6mm in the opening. I think the w-20a comes with a sleeve also but not sure.

On the w-20 and w-20b they use the same indenter cylinder housing length so on the 20b, with the longer 8mm spacing in the opening, the indenter isn't long enough and will not touch the anvil without the calibration sleeve slipped over the anvil. It will test .6 thick metal without the sleeve but not be long enough and come down far enough down to test case necks as they are not => .6. That is why it won't work.

I hope you are lucky and get a brand that uses the bare anvil to calibrate on the w-20b then you will be good to go.

I saw this info on a video but I can't find it now or I would post it.

This why I bought the w-20 instead of the w-20b.

I saw models with a sleeve as well. I targeted ones specifically without one though making an anvil isnt exactly rocket science. None is included in the materials list, or mentioned in instructions anywhere, or can be seen in the pictures of "what you get" or laid out in the case. Maybe/probably I'll get lucky. To me it looks like only the 20a would need a sleeve since it has to be physically different with a 10mm anvil but a 13mm max opening.

[Zeneffect]

Arrived today



No anvil sleeve, probe comes down to the 6mm anvil fully just fine.

[jasper2408]

Looks good. You are good to go now.

[Zeneffect]

Yep, already taking off the nose to clearence cases. Initial testing shows... I am a touch harder than factory annealed. Not bad, not great... could do better.

And done. Nose is trimmed, anvil is shaved on 3 sides to fit 223case mouth. One of the few tools you can take a grinder to and increase its value.

[jasper2408]

One of the few tools you can take a grinder to and increase its value.

If you really want to up the value stick a piece of duct tape on it.

[Zeneffect]

Oh the wonderous wonders of checking your steps. Tools can be awesome or terrible.

In this case, awesome

So.....

Fired brass reads 17. My annealed brass reads 14. Virgin lapua reads 15.

Typically I decap, clean, resize, anneal, then partial resize again by running through the expander ball/mandrel only. The above values gave me the info needed to see what that last step is doing. It still work hardens slightly and brings the reading up to 15, exactly the same as lapua virgin brass which would explain the near infinite life I've been seeing.

Just food for thought, that $200 saved me easily that much money in range time/fees, ammo, etc finding out using long running data.