Originally Posted By: Bman
"Brass is well done in both pictures, put in the scrap pile."
There is nothing wrong with ANY of the brass on this thread.
The difference on color is due to the difference in fuel gas (propane or natural gas, or other), and the mix of air to fuel gas. Very colorful brass comes from torches that have an excess of air - almost colorless brass comes from torches that have an excess of fuel and are somewhat air deficient.
Here is some interesting data that will dispel some of the wives tales (passed on by the know-nothings) about annealing.
Data on brass...
Physical Properties
Density 0.308 lb/in³
Mechanical Properties
Hardness, Rockwell B 91
Hardness, HR30T 77
Tensile Strength, Ultimate 94300 psi
Elongation at Break 3.00 % In 50 mm
Fatigue Strength 23200 psi
Machinability 30 % UNS C36000 (free-cutting brass) = 100%
Shear Modulus 5800 ksi
Shear Strength 47900 psi
Thermal Properties
Specific Heat Capacity 0.0896 BTU/lb-°F
Thermal Conductivity 120 W/m-K
Melting Point 1680 - 1750 °F
Processing Properties
Annealing Temperature 797 - 1380 °F
Hot-Working Temperature 1340 - 1560 °F
NOTE THE ANNEALING TEMPERATURE!!!!
Now here is something on what things look like at what temperature...
Color °F
Faint Red 930
Blood Red 1075
Dark Cherry 1175
Medium Cherry 1275
Cherry 1375
Bright Cherry 1450
So... when you see the neck and shoulder become full cherry red, you are still inside of the annealing zone, and if you DO NOT see red, you might not have reached the annealing temperature, and all you've done is put pretty colors on your case necks.
So, this is not "my opinion" about the temperature - this is standard metallurgy science.
People that tell you that you have ruined your cases if you exceed 475, have no idea of what they are talking about - at 475, all you have done is waste propane.
I keep the lights low - a florescent on, 10 feet behind me, no light at the annealing place. Then I heat the cases until I see the necks and maybe the shoulder turn read, but not "bright red", then I drop it on a crumpled piece of aluminum foil to cool.
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