Hardness Tester

[BABore]

I recently designed and built a few hardness testers that mount in a standard reloading press. They seem to work real well and are accurate and repeatable. I sent off a couple for evaluation including one to Dan, at Mnt. Molds. He posted his results along with some pics.

http://www.mountainmolds.com/phpBB2/viewtopic.php?t=162

[StarMetal]

BABORE

Pretty neat. Looks like you used an automotive valve spring for your spring. I know those are rated in pounds and you can buy them at various rates. Is that what you used?

Joe

[BABore]

Actually it was a Danly die spring. Calibrated the load on a hydraulic press equipped with a digital load cell.

[GregP42]

Actually it was a Danly die spring. Calibrated the load on a hydraulic press equipped with a digital load cell.


BABore,

That is too cool, you going to make them for sale?

Greg

[BABore]

Not quite sure if I am or not. I have a few extra made up though. I'm currently sending a few out for field trials to get some feedback. Maybe a few for bartering. I mainly built them to see if I could and cause I'm a cheap bastage.

[Willbird]

I hacked up an excel spreadsheet to calculate the hardness from ball size, load, and dia of indent.

I guess I need to make up one myself.



Bill

[BlueMoon]

That tester sounds just like what my Lee tester does on a flat place on ingot or bullet. You hold a spring pressure down for 30-60 seconds, in your press, with a rod even with the top of the spring die and look through a magnifyed glass, with a scale on it, to measure the width of the dent. Then look in Lee's chart to find BHN.

Bill

[Buckshot]

.............BABore, very nice. Similar to the one in the Lyman cast bullet manual. Variations on a theme. Your's looks very nicely done. Several years ago I decided I needed a hardness tester and made up one like this:

http://www.fototime.com/F52103C79C7E717/standard.jpg
The above was the prototype. Materials were simple to get. The body was merely a piece of black steel gas pipe. The base was a 7/8-14 bolt with a 1/2" hole bored though it. The bolt head had a step turned in to mount the pipe and then the 2 were welded together, then the hexhead turned round.

A piece of 1/2" drill rod for the piston rod, an aluminum piston and a 7/16" steel ball bearing. The spring came from open stock at Pep boys.

http://www.fototime.com/2AFEBDCA5CFA504/standard.jpg
This is what I ended up making as a prototype for production. I decided turning the bolthead round served no purpose other then appearance. The turned aluminum cap was also dispenced with and a heavy cotter key serves to retain the spring.

The piston carries a pointer extending through the milled slot and there are 2 marks. The lower is 100 lbs and the upper is 150 lbs. I use the 150 lb one to give larger easier to see impressions. Especially in hard alloys.

Lower left in the photo is the mould I made for sampling, using a 1" cast iron pipecap turned smooth inside and faced off, with a simple aluminum sprueplate. The mould handle was cropped out of the photo. On the press in front of the device is a sample casting with the imprints from the BB at 150lbs pressure which allows you to measure several imprints, and not requiring a slug with a large meplat. You can use one by setting it on a piece of steel on the top of the ram. The BB is co-incident with the ram's axis.

To calibrate the device I bought two 1lb bottles of labratory pure lead, cast sample ingots and imprinted them under 150lbs of pressure, using a bathroom scale on the drill press. Not ultimate precision, but close enough.

I'd made up 10 units but never did get around to doing anything with them, as Gussy had come out with his lead hardness tester at that time and I didn't want to interfer with his. I did give one to Deputy Al. They're handy when batching, or to confirm hardness when rendering down WW and other scrap, or wanting a specific hardness for certain loads.

..............Buckshot

[Mel-4857]

Thats great work by both you fellas. Buckshot if you're willing to part with one of your testers I'd gladly pay. I know it would get lots work up here. Our club up here in Nova Scotia, Canada shoot a lot of cast in Mil surp and others. We share moulds or cast for each other. I know the 6.5 mould will be here soon and will get a work out; I have 3 Swedes and I have two friends who have at least another six 6.5's of varying types. It's great to see ingenuity at its best. Mel

[Pop_No_Kick]

Wow ya'll THAT GREAT !!!

Keep it up!!!

chuck

[GregP42]

BABore,

Hahaha, I know all about cheap, just ask my x-wife! If I had the tools I think I might be able to make one, after maybe a month or two of messing them up.
If you do decide to sell one let me know, I think it would be a good tool to have.

Greg



Not quite sure if I am or not. I have a few extra made up though. I'm currently sending a few out for field trials to get some feedback. Maybe a few for bartering. I mainly built them to see if I could and cause I'm a cheap bastage.