whisler
02-04-2019, 01:36 PM
I have started using the pencil hardness method for checking my alloy since determining that my 9 mm needs about 13 BHN alloy to avoid leading, at least with my powder of choice. I was a paint chemist and am quite familiar with how the test is performed as it is a common test in that industry.
I decided to water quench some wheel weights to use, and sized withing 24 hours through a Lee sizer die, since I had read that they will harden quickly and become hard to size. After 1 week, 2 weeks, and 3 weeks the boolits were only checking 13 BHN. I thought this was strange since I knew the alloy was wheel weights because I processed them about 2 months before. I chalked it up to use of recycled lead for wheel weights and wasn't too concerned because I only needed 13 BHN any way.
About 3 weeks later, I checked the boolits again and they now check 20 BHN. I didn't think it took 6 weeks for water quenched hardness to kick in. I got the hardness that I expected but in 6 weeks not a matter of days. Anyone have any idea what's going on here?
Edit to add: These were all clip-on wheel weights and were water quenched from the mold. Pot temperature was approximately 725 deg.
I decided to water quench some wheel weights to use, and sized withing 24 hours through a Lee sizer die, since I had read that they will harden quickly and become hard to size. After 1 week, 2 weeks, and 3 weeks the boolits were only checking 13 BHN. I thought this was strange since I knew the alloy was wheel weights because I processed them about 2 months before. I chalked it up to use of recycled lead for wheel weights and wasn't too concerned because I only needed 13 BHN any way.
About 3 weeks later, I checked the boolits again and they now check 20 BHN. I didn't think it took 6 weeks for water quenched hardness to kick in. I got the hardness that I expected but in 6 weeks not a matter of days. Anyone have any idea what's going on here?
Edit to add: These were all clip-on wheel weights and were water quenched from the mold. Pot temperature was approximately 725 deg.