Some annealing explained

[jackieschmidt]

Thanks. Great video. I watched all 43:32 of it. I will own a Webster Hardness Tester one of these days.

Agree with both points. I did finally watch the video and think that although it's a "new" hardness scale to try and make sense of (he mentioned the difficulties and problematic nature of conversion to another scale) it does provide some level of pre and post hardness measure. at a bare minimum it can give some level of assurance on whether or not it annealed to some degree. It's a good next step to move along the conversation and create some sort of comparison to pre and post annealing states. I think everyone is is tired of the same old arguments

I have no doubt that there will be more testing in the community and it will offer someone a boutique opportunity to machine and sell a range of caliber specific pilots for the tool!

Let the testing begin!

^^^^^^
At the very least the guy in the video has come up with his own method of testing the brass to see if the annealing did indeed soften the brass back to his standard, which for his purposes is a new Lapua case.

He did mention the fact that some target shooters that load single shot simply use such a small amount of resizing the neck that all the tension does is keep the bullet in place under the usual handling of it. I do this with my 30BR.

Of course, this is impractical for any application where the rounds are Fed from a magazine and are subjected to the inertia of recoil.

 

[rox]

I just bought one of the cheap versions of the tool from Amazon. To test it I cut-down a .308 case at the body/shoulder junction, so it would fit over the stock mandrel. I found I was able to distinguish between a multiple-times-fired case before and after a crude anneal on a gas stove.

We then set about reducing the mandrel size. The mandrel came out easily with heat applied. Our plan was to reduce it to .22, so we started on the lathe to remove the bulk of the material (it is hard!) then finished on a precision grinder.

Unfortunately the reduction was too much for the limited stroke of the tool. Gauge pins should be arriving for the second attempt any day now. This time we'll stick to around .300. We may try an offset mandrel to support smaller sizes after that. I suspect we may need to take a little material off the indenter cylinder to avoid interfering with the neck.

 

[Webster]

Thanks for very informative posts.

I was wondering whether a point indenter is necessary for a very thin wall as in a case wall. Why not use a spherical or elliptical indenter? Since any permanent indent in a material is evidence of a force beyond the elastic limit of the material and plastic flow.

I don't think it is in the ASTM Spec but I believe I read somewhere that the metal thickness should be at least 10 times the depth of the indent. ASTM spec states that there must not be any brinneling marks on the back side of the sample. A brinneling mark is a shiny spot on the back side from microscopic level metal flow from the load on the indenter.

I don't feel like rereading the article, but the mandrel that's inserted into the neck must be a cylinder close to the i.d. of the neck for support. Judging by the size of the spring on the Webster tester I would think the load on the indenter may be to high for a piece of brass 0.0125" thick. What's the depth of the indent compared to the total indenter point? Is it bottoming out on the large flat behind the point.?

 

[6MMsteve]

calibration test blocks for ductile iron for Hardness tester at work in the lab where about 3/8 in thick and cost around $300 per block think they was 2.5x2.5 or 2x2, never used one, I just done hardness test on castings, when they was complaining about tool wear, in which usually it was coolant out of spec, nozzle direction, or atomization or dirty table beds. and I have used the 316 scale with the brinkman flashlight and crosshair scaled then used the lit to find the diameter of the strike which the ref called the hardness

 

[JJC]

Nice article on full annealing cartridge brass and the metallography involved. https://vacaero.com/information-res...rmation-and-annealing-of-cartridge-brass.html

Papers/ presentations on Vickers hardness testing. George Vandervoort has many articles on metallography. http://www.georgevandervoort.com/category/metallography/page/6/

A repeatable process is probably more important than the actual values as long as you don’t full anneal the case head when stress relieving / annealing.
Lots of articles out there in the heat treat world on the Vac Aero website under the Resources tab , by Dan Herring, Vandervoort and Dan Kay.
JC

 

[jackieschmidt]

The AMP people seemed to do a thorough research on annealing cartridge brass as part of the development of their induction annealer.

Induction Annealing Brass | Our Research | AMP

View the latest articles from AMP Annealing. Get tips and tricks from our R&D. Here we upload articles to provide your the best possible information on innovations in the annealing process.

www.ampannealing.com

Their findings are not conjecture. Granted, they are selling a product, but part of a good marketing profile is the ability to show data to customers.

 

[mikecr]

Keep drinkin the kool-aid

 

[Webster]

Keep drinkin the kool-aid

How many 1000 post and replies do we need every year on annealing. What's it take to end it?

 

[mikecr]

I've been following gun forums from their inception(late 80s), and I've yet to see a loop hit true resolution and take a set. But once in a while someone says something sincerely different, that get's you thinking.
With that, it's all worth it right there.

 

[justinp61]

Interesting video.