dgfoster
Diamond
- Joined
- Jun 14, 2008
- Location
- Bellingham, WA
Gard,
Your punch and measure the divot idea is used on some commercial hardness testers. If I were going to try to shop-make such a device to get a rough idea of hardness, I’d start with one of those spring-loaded center punches. It would provide a pretty repeatable impact. You’d need to experiment with the cone shape of the end. I’d start with a 120 included angle. Use one of those 5 dollar 45x pocket microscopes to measure the crater. I think you could distinguish Rc10 from 25 and 25 from 45 etc pretty reliably if you worked at it. I use both Leeb and Wilson testers and can see relative indentation sizes differences with the naked eye. Magnification and a fine scale will give you some ball park info. If you do this, post results here.
Send me coupons of samples and I will do more formal tests for you gratis to help you get started.
Denis
Your punch and measure the divot idea is used on some commercial hardness testers. If I were going to try to shop-make such a device to get a rough idea of hardness, I’d start with one of those spring-loaded center punches. It would provide a pretty repeatable impact. You’d need to experiment with the cone shape of the end. I’d start with a 120 included angle. Use one of those 5 dollar 45x pocket microscopes to measure the crater. I think you could distinguish Rc10 from 25 and 25 from 45 etc pretty reliably if you worked at it. I use both Leeb and Wilson testers and can see relative indentation sizes differences with the naked eye. Magnification and a fine scale will give you some ball park info. If you do this, post results here.
Send me coupons of samples and I will do more formal tests for you gratis to help you get started.
Denis