Machining in Tenths

[mdenz3]

The only thing that I can add to this discussion is about the metals used.

4140 is not tool steel. If you want tool steel that won't distort or leave much scale, you need to use A2. Another good one (my opinion) is 50100, it comes mostly in bar stock. It's not listed as tool steel but, it's what most ball bearings are made of. Neither are easy to machine like 4140 but, will last MUCH longer. The top end tool steel for this application would be D2 but, it's harder to work with than either of the above. P20 tool steel (for injection and rubber mold work) is similar to 4140 but, is not for this type application.

There are others TOOL STEELS but, I haven't worked with them. For hardess and wear resistance you need at least .80% carbon content.

Frank

I do a fair bit of work on D2, and have never had any real trouble. You can't beat it for wear resistance and holding size during heat treating (though it will have to be professionally done in a vacuum furnace). Personally I wouldn't make dies out of anything else.

[M-Tecs]

You can’t go wrong with D2 or D3. For extreme wear resistance I like Carpenter's Hampden® No. 610® (D2) Tool Steel.

http://www.cartech.com/toolsteelspow...432&terms=*d2*

http://www.matweb.com/search/datashe...0978b56266bde1

http://www.suppliersonline.com/propertypages/D3.asp

http://www.matweb.com/search/datashe...9c908dc11154e6

[Red River Rick]

Brian:

What can one say.........looks like you have everything WELL under control!

I see some very nice products. They look well made, and not whacked out in the back shed with a drill press and a file. Reviews have been positive as well, so you must be doing something right.

I have a few items I'd like to discuss/share, but I'll do that in a PM.

Question: When you check your dies for hardness, after heat treating, do you use the "Concrete Floor" method?


RRR

"Don't Melt..............Squeeze"

[BT Sniper]

LOL Good to hear from you Rick. Wish I could send some bullets your way. If you ever make it down to a US address let me know.

BT

[MBTcustom]

Once you get your head screwed on strait, machining in tenths is no harder than thousandths. It definitely takes more skill, but once you get the hang of it its NBD. Machining big stuff that weighs several hundred/thousand pounds is the same way.
What's hard is working in a job shop where you might go months doing +-.005 parts that you can hold in your hand, and then one day you have to make a super precision +.0001-.0000 part and you have to shift gears real quick and dont screw up. In my present day job, I work with tight tolerances all the time. It becomes very important to maintain a consistent temperature throughout the fabrication and assembly process, because a change of 5 degrees can through your part out of tolerance.

[BT Sniper]

Yep lots of factors to take into consideration and I am happy to maintain a bullet within +.0005 - .0000 of nominal bullet diameter.

BT

[MBTcustom]

I'm sure you already know this, but diamond lapping compound makes short work of long lapping jobs.
It sure is cool when you get things going your way!

[mdenz3]

If anyone of you hobbyists are interested I have four WNMG 432 style inserts for free.
They are from an old promotion and I'll never use them for production so I'll offer them up for anyone who can use them.
Pic here: http://i.imgur.com/WDmKY.jpg

PM me if you want them.

[Rangefinder]

Brian---all of my machining right now IS on a drill press with a file, so to speak---I set up my wood shop, haven't had time or money to even address the metals side of it yet. Got plenty of know-how Dad was a master machinist for Westinghouse Corp once upon a time and his shop was my daycare, but currently it's like trying to paint the Mona Lisa with an Ace Hardware brand paint roller. SO, that being said, YOU ARE NOT ALLOWED to get burned out before I gather enough change from my couch to get the dies from you on an ever-growing list! For fair warning, it could take a while to complete my list . We both may be bald by then...

[BT Sniper]

I've got to much $ and inventory invested to get burnt out. I got enough work with all the inventory for probably better then 3-4 years worth of work to keep me busy.

BT