Full Length Sizer Boring

[Bullet bumper]

Remember you can buy A2 in drill rod, and that puts you ahead of the game from the start. Before buying any, I'd check to see if my heat treater was setup to do air hardening steels. Most are. I used to have an in with a major heat treater that could do it all in vacume furnaces, and he'd do my high speed steels for a six pack of beer if I wasn't in a big hurry (never are). A die just dosn't have to rockwell at 62 contary to popular beliefe. Even 55rc will do nicely.

I almost always setup with a standard type cobalt drill to get a hole thru it with a spray mist coolant setup. Then I cleaned up the drilled hole with a carbide boring bar. After that (believe it or not) I went in there with a four flute core drill to get the bore within about .025". Cleaned it up once more and reamed it. I'm sure there are better ways, but that always worked well for me.
gary

Finding someone who stocks drill rod is not that easy over here . If they have to get it in special for me they will charge an arm and a leg . Australia is a consumer wilderness compared to the US . However I will ask around .
You are right about hardness . It does not have to be 62 RC or anything like it to give good service for home use .
I can drill Bohler K110 D2 with HSS drills but it has to have flood coolant and go slow . If you heat it up your finished . Turns real good with cheap C4 grade inserts but again keep it cool .

 

[Bullet bumper]

Hey guys,

This is one heck of a conversation. I have no idea of what you are talking about regarding types of steel etc. but. . .

How in the heck is a pointing die made? What kind of a tool or process is used to get the ogive and point. I'd really like to understand more about that.

Regards,
Roy

I have not actually made a point forming die yet , made core seater's and swagers as they are the easy ones.
However I can give you a rough idea .
Turn the ogive and diameter you want onto a shaft of tool steel a certain amount under finished bullet diameter . Using a ball turner . Then mill it to a half reamer and heat treat . You would make two or three just in case . Then using the same settings turn up some brass lapps.
starting under size and working up to the bullet diameter
Then you have to turn up the blank . I would just turn it straight and square to start with as you don't want to waste threading the outside in case you screw up the cavity .
Step drill the basic cavity , then ream it to shape and under size . Then lapp the cavity out until it is approaching finished bullet size but still with meat left to lapp out after heat treating .
Then finish turning and threading the outside .
After heat treating continue lapping.

The hard part is getting the smooth finish to come up just as the correct finish diameter is produced. The advantage of the home hobbyist is that you have way more time to get it right than the pro's . So you can lapp a lot longer on the fine grit to preserve the finish waiting for the right diameter.
If you only have one lathe you may have to remove the die from the chuck and lapp in a fixture as you may need the lathe to make extra brass lapps.


I have a lot to learn myself but that's a rough guide.

 

[royinidaho]

Bullet Bumper,

Thanks,

I guess there just ain't no free lunch. . . . as usual. . .

 

[Trickymissfit]

Finding someone who stocks drill rod is not that easy over here . If they have to get it in special for me they will charge an arm and a leg . Australia is a consumer wilderness compared to the US . However I will ask around .
You are right about hardness . It does not have to be 62 RC or anything like it to give good service for home use .
I can drill Bohler K110 D2 with HSS drills but it has to have flood coolant and go slow . If you heat it up your finished . Turns real good with cheap C4 grade inserts but again keep it cool .

I was thinking about D2 last night and the gist of the thread. Found an old Carpenter Steel manual laying about, and gave it a look thru. They felt that D2 would have been a good forming die (generic). Machinability is down from some of the others, but typical for tough air hardening steels. Regarded as one of the worst steels to grind (I never had any problems). But the same manual rated Stentor (they called it out as an O-2, but think it's closer to most O-1's) better for forming dies and machining. Now I have not cut Stentor in eons, but from what I can remember it cut just about as good as 8620. You don't get much better than that! One thing to remember about a lot of oil quench steels is that the quench process almost never ends with them. Put the parts in a freezer for as many months as you can stand, or better yet have them cryo'd. I always put tools I was building for myself in a deep freeze for about a month or even longer (-40f degrees).

Bohler is a company, I've never been around. But if you drop them a note asking for the heat treat data, they'll usually supply it. What your after is the draw process to get the blanks back down to about 52-55rc. My data shows 1100f degrees for a 50rc or slightly harder. This seems low to me, but they for sure know more than I do. The cool down process will take most of the day and can be tricky
gary

 

[SidecarFlip]

Not at all into home heat treat. Too many reputable atmospheric treaters around here. Atmospheric Anealing is who I use.

They run most of the valve train components for the automakers. Buy the cheapest drawing quality (100X AKDQ) material and controlled atmosphere treat it to the specification required. You can literally take junk and make a silk purse. It's all in the process.

I would think that Starrett AH, WH or OH drill rod would be available in Oz. As an aside, Global Industrial offers metric and SAE OH, AH and WH rod and they sell internationally. Brand wise, not sure of the orign.

I make a line of specialty AGD indicator extension rods for gaging the timing of a diesel engine (to get to the piston crown through the injector port). I sell them to technicians in the trade. I HT them in the shop and oil quench but they are small diameter and easy to treat.

 

[Bullet bumper]

Not at all into home heat treat. Too many reputable atmospheric treaters around here. Atmospheric Anealing is who I use.

They run most of the valve train components for the automakers. Buy the cheapest drawing quality (100X AKDQ) material and controlled atmosphere treat it to the specification required. You can literally take junk and make a silk purse. It's all in the process.

I would think that Starrett AH, WH or OH drill rod would be available in Oz. As an aside, Global Industrial offers metric and SAE OH, AH and WH rod and they sell internationally. Brand wise, not sure of the orign.

I make a line of specialty AGD indicator extension rods for gaging the timing of a diesel engine (to get to the piston crown through the injector port). I sell them to technicians in the trade. I HT them in the shop and oil quench but they are small diameter and easy to treat.

You would be surprised on what is not easily available over here . Sure they can get anythng you want up from Melbourne or down from Brisbane but the costs are excessive. I went some time back to get a 3/8 diameter rod of stainless. They wanted $60 for a meter. I just said , forget it.
Americans would tear their hair out in clumps if they had our consumer nightmare to deal with . If I lived in Sydney or Melbourne the situation would be much better but I don't .
Since we lost our steel mills to overseas the cost of metals has risen sharply.
We dig out iron ore by the millions of tons and send it overseas to turn into steel then pay through the nose to buy steel back , it's moronic.

 

[Trickymissfit]

You would be surprised on what is not easily available over here . Sure they can get anythng you want up from Melbourne or down from Brisbane but the costs are excessive. I went some time back to get a 3/8 diameter rod of stainless. They wanted $60 for a meter. I just said , forget it.
Americans would tear their hair out in clumps if they had our consumer nightmare to deal with . If I lived in Sydney or Melbourne the situation would be much better but I don't .
Since we lost our steel mills to overseas the cost of metals has risen sharply.
We dig out iron ore by the millions of tons and send it overseas to turn into steel then pay through the nose to buy steel back , it's moronic.

for building a forming die, your simply not going to beat Accuralloy from Baldwin. The stuff comes with a 30rc hardness, and takes a nitride process like nothing I've ever used before or after. Plus it's as strong as all get out! I bet Baldwin has a dealer down under, as they are known world wide. Be worth the time to email them!

As for drill rod, I'm with "Flip". You can't get anybetter than Starrett. I had two racks of their drill rod all the way out to 1.25" and 30mm. But I steadilly replaced using it with Accuralloy and Nicralloy from Baldwin. The guys cutting the stuff always said there was a difference. The same can be said of Starrett gauge stock, and trust me I've been stuck with the generic stuff too many times in the past!
gary

 

[Bullet bumper]

for building a forming die, your simply not going to beat Accuralloy from Baldwin. The stuff comes with a 30rc hardness, and takes a nitride process like nothing I've ever used before or after. Plus it's as strong as all get out! I bet Baldwin has a dealer down under, as they are known world wide. Be worth the time to email them!

As for drill rod, I'm with "Flip". You can't get anybetter than Starrett. I had two racks of their drill rod all the way out to 1.25" and 30mm. But I steadilly replaced using it with Accuralloy and Nicralloy from Baldwin. The guys cutting the stuff always said there was a difference. The same can be said of Starrett gauge stock, and trust me I've been stuck with the generic stuff too many times in the past!
gary

As far as I can see from Baldwins info it's similar to 4140 , tha't what they compare it too . they don't have any info on dimentional stability after heat treating so I think I will stick with Bohler K110 for bullet swaging dies as it's a known quantity .

 

[SidecarFlip]

I must comment that dimensional stability as it pertains to commercial heat treatment is entirely in the hands of the heat treater and their competence level. No supplier will guarantee dimensional stability that I know of, however the people I deal with come through consistently with very littel dimensional change.

There will always be a bit, after all you are realigning the structure and it will move.

 

[Bullet bumper]

I must comment that dimensional stability as it pertains to commercial heat treatment is entirely in the hands of the heat treater and their competence level. No supplier will guarantee dimensional stability that I know of, however the people I deal with come through consistently with very littel dimensional change.

There will always be a bit, after all you are realigning the structure and it will move.

Yes and No , Some steels have greater stability than others and as Baldwin does not give any comparisons to other steels I tend to stick with what I know and can get. The very reason that heat treaters don't give any guarantees is the reason I use a steel with a reputation for dimensional stability during heat treating .
It's a whole different ball game for the armature only wanting a small amount of steel compared to shops ordering it by the truck load .
It's a mute point anyway because there is no Baldwin agent that I can find .

 

[Trickymissfit]

As far as I can see from Baldwins info it's similar to 4140 , tha't what they compare it too . they don't have any info on dimentional stability after heat treating so I think I will stick with Bohler K110 for bullet swaging dies as it's a known quantity .

The only brand of steel I felt was more stable than Baldwin was from Timken, and that was the 52xxx bearing steels which are a different animal. Their 4150 (accuralloy) is extremely stable in a nitride process (I used nothing but plasma)
gary

 

[Trickymissfit]

I must comment that dimensional stability as it pertains to commercial heat treatment is entirely in the hands of the heat treater and their competence level. No supplier will guarantee dimensional stability that I know of, however the people I deal with come through consistently with very littel dimensional change.

There will always be a bit, after all you are realigning the structure and it will move.

good point! There is virtually no steel that dosn't change under heat. Some more than others. I've even seen 4xxx series steels change all over the place in a nitirde process. Looking in the Carpenter manual, they do spec the change outs, but I think that's a lot of guess work.

For a heat treat some to get my buisiness, they must be of aircraft quality first. Then I look to see if they can do the exotics, as this gives me an idea what they can and cannot do. I'm lucky as I have two in my area. One is a small shop about ten minutes north of me, but if it's gotta be seriously right I goto one up in Indy. I probably didn't use either one a dozen times as I had access to a state of the art heat treat facility. But I liked the way the one in Indy did air hardening processes best.

You are probably a light year more upto date on steels than I am for the most part. I may have delt with some of crazier exotics but you still ahead of the game here. I honestly think the operator doing the draw process is more imortant than the guy doing the initial heat treating and quench processes (also can be extremely critical). I've had a few jobs trashed by the quench tank alone! The best thing I ever did was to order in a good agitating system to seriously circulate the quench oil. Then I brought in Castrol and a couple others to try different oils. I settled on Castrol by the way.
gary