Wow, reserected from nearly two years ago.
Appleseedgunsmith, nice die. Looks great.
Well, to update a little, I sold my Grizzly 10", and bought a Atlas 10" QC54. About a 1954 model. The little lathe runs like a clock.
The Grizzly wouldn't turn down slow enough to suit me. It had "change gears" which I didn't care for. And didn't have enough different speeds.
So, I haven't made a whole lot of items. I still do use 7/8 x 14 bolts for some of my items. I have learned to cut threads. Not a bunch of them, but good ones. I turned a sleeve and threaded it on the inside 7/8 x 14 to hold and center my threaded stock (bolts) when making my dies. I must say, I WAS very proud of my internal threads on the piece when finished.
The first set of dies I made were for making 45 acp shot loads. I used an old article from the NRA for the specs. They turned out very nice, and worked great.
My last venture was to make a sizer die to size down the Lyman 525 Sabot slug, so I could use the slug in wads with thicker petals. The sizer works just fine. The side walls are thin, but it does the job very well.
Been sluffin off on the machining, but still looking forward to keep on learnin.
Regards
Jack
Last edited by littlejack; 11-26-2014 at 01:05 AM.
My grizzly has the change gears too. What a pain! Maybe someday......
I just got thru reading this thread again and what I noticed is the lack of real heat treating information.
Since it is the day before Thanksgiving and I'm bored I will relate some of my knowledge on this subject. I have done a considerable amount of heat treating using materials such as 4130-40, O1, A2, D2, and a few others probably nobody here has heard of. I have also done much heat treating or more properly, "Case Hardening /Carburizing" of parts made from 12L14 and other soft steels. I like this process as you can make good looking parts out of easy to machine materials and then case harden them to be just as good as parts made from other materials that are harder to cope with.
First; all materials have a Tensile strength. usually measured in Pounds per Square Inch or PSI. All materials also have a "Machinability Rating" which is calculated in percentages of the machinability of 1018 Cold Rolled Steel which is the established Bench Mark or Standard. 1018 CRS also has a Tensile strength of 60,000psi.
1018 CRS cannot be heat treated to increase it's TS simply because it doesn't contain enough carbon 0.18% (IE: the last two digits of the series number denote the carbon content.) As the carbon content increases the ability to harden increases and the level (Rockwell Hardness Scale C or Rc) the material will harden to,,, increases. IE 1040 will achieve around Rc 52-55, 1060 will go Rc 57-58. 1095 will go to Rc 63 and that's why they make files out of it. However it is very brittle at that level and the reasons are two fold. One is because it lacks Alloying Materials which enhance toughness, and the other is that it has not been Tempered. Unfortunately just tempering it won't get you much as the other materials aren't there.
This is where Alloy Steels come in and the most common of them is the 4000 series which is Chrome Molybdenum Alloy Steels. There are many others and a trip to the Earl M. Jorgenson Website will bring you up to speed. all have specific desirable properties and are used in applications which exploit those properties.
When it comes to the actual heat treatment of any given material there is a certain process for that given alloy.
The basic rule of thumb is the material has to be heated to it's "Specific Hardening Temperature" and soaked there for a period of time. That period of time insures that the all of the material "sees" the hardening temperature.
The Rule is,,, 2 Hours at Temp for every 1" of thickness. That means if you have a 1" cube of O1 tool steel you will soak it for 2 hours at 1450F and then immediately quench it in room temp oil to achieve its full hardness. this will take about 3 hours as the material has to come up to temp before you can soak it at that temp.
There are few fine points which everyone needs to understand.
First; if you set your furnace at 1450 F your part will never reach 1450 F. This is because the part can only absorb a percentage of the heat available thru all three methods of heat transfer, and none of them are 100% efficient. So you heat the furnace to 1500-1550 F and the parts will achieve their complete hardening temp. You are now in the "range" so to speak.
Second; the medium that is used for quenching has to do with the rate heat must be extracted from the material to insure the desired grain structure in the end. Water is the fastest, Oil is next and then Air Quenching which is the slowest. Each material has it's own needed rate of cooling.
If the process is done correctly the end result is a part that is hardened to the maximum level for that material.
Next the part must be Tempered or "pulled back" to the desired finish hardness. In this part of the process the material is heated again to a lower temperature and held there again for a period of time and then removed and allowed to cool in air. The tempering temp is usually between 400 and 1000F and typically the higher the temp the further the material is pulled back. In a Tool Steel like A2 that goes off at 1750+F and 63 Rc that typical tempering cycle will be to raise the temp to say 700 F, soak it for 2 hours and then air cool it to yield a final hardness of Rc 56-58.
Please note: There are specific and well established processes for heat treating every material that can be done, and the predicted range of hardness (usually 2 points) will be there unless there are discrepancies in the material itself. IE you are making a run of grade 8 bolts out of 4140 Cromo Steel which are to be hardened to 150K psi. They come out at 120K psi. Because the material you thought you used actually was something else. IE: you get to start over and this is why we require Certifications with all materials. So we know what we got and if we didn't get it then someone else gets to pay!
A few more tidbits of info.
Any time you heat steel of any kind beyond about 1400 F you get a scale build up on the exterior. This is known as "Carbon Precipitation" or plainly, the carbon is coming out of the alloy due to the presence of heat and oxygen.
At the low end of the scale this is no big deal and we will simply bead blast the parts and be done with it. However when we get into the Tool Steels like A2 which goes off at 1750F and D2 which goes off at 1950F, and there are some that go off at 2150F,,, These materials are literally white hot and if oxygen is present they will burn!
To eliminate this problem these materials must be heated in either a Vacuum Furnace or a furnace that is being purged with Inert Gas such as Argon. Parts processed in this manner come out clean and have no scale build up of any kind and have not lost any of their carbon content,,, they also look bitchin' !
I hope this exhaustive blurb has helped some of you understand this thing called "Heat Treating" a little better. There are certainly many variations to these processes, however the entire subject is pretty much as I have laid it out above.
Happy Thanksgiving 2014!
Randy
"It's not how well you do what you know how to do,,,It's how well you do what you DON'T know how to do!"
www.buchananprecisionmachine.com
Randy, thank you and I'm glad you were bored yesterday.
I don't do a lot of heat treating but every bit of information helps.
Never realized the last two digits of the series number denote the carbon content, good to know.
Thanks again.
"An armed society is a polite society" R.A. Heinlein 1907 - 1988
That is very useful info Randy.
I just recently got a lathe and have learned that threading isn't as difficult as I thought it would be. No all thread or bolts for me.
It is a good to know we have people like Randy, Keith, and a few others who can give us this sort of information. Thanks guys.
You will learn far more at the casting, loading, and shooting bench than you ever will at a computer bench.
Randy, very good post, but I must politely take issue with two points.
1. I thought that machinability rating was based on using B1112 steel, not 1018. But I think 1018 probably has about 100% machinability rating so I doubt it makes much difference which material you use as a comparison.
2. I keep a magnet near our heat treat furnace, and as soon as any steel is fully austenitized (changed to a crystal structure that is a Face Centered Cubic which is nonmagnetic) then it is ready to quench. I have heard the "two hours per inch" rule but only on when used on highly alloyed steels such as some tool steels. The problem I've found with thick sections is cooling them fast enough, not so much on heating them. I find that once a material is fully austenitized then any further soaking just makes for a coarser grain structure and a lot more scale.
By the way, I use stainless steel foil tool wrap when I have parts that I don't want to get scaly. Really handy but be careful, every time I use it I end up cutting myself somehow.
We all have different life experiences, you won't go wrong following Randy's advice.
Thanks to the experienced from me also.
About the only tempering and/or hardening I have done was the making of some shop tools in my trade (welder/fabricator).
After listening to the "old hands" (advice from my dad) in the shops, I learned about some of the processes.
"Listening" was the best advice I ever got in life. Dad was right.
Anyway, to you "old hands" much obliged.
Happy Thanksgiving to everyone.
Regards
Jack
Wow! I really enjoy reading the great info provided in this topic!
I am a hobby machinist and have had only the high school shop level of back round. .....40 + years ago.
I have WWII era small shop equipment and really enjoy making useful items and reloading equipment and gun parts as well as lining old barrels. Tho my father was in the trade before WWII then the Navy gun factory in DC during WWII and then again for many more years after the war, he did not have time nor me the willingness to learn when I had a chance when I was young and at home.
Now, I have his modest home shop tools set up and I am learning as I go.
Info like this is great! Keep it coming! Lots to learn!
-Michael Rix
PS - if you have a lathe, cutting 7/8 - 14 die threads is cake and just jump in and learn...
Chill Wills
as for heat treating, well, there are "upper critical", "lower critical", "tempering", and "annealing" temperatures that are remarkably consistent across the spectrum of low-medium carbon steels and alloy steels. upper critical = normalising = 1655*F plus or minus 10*, at which steel becomes non-magnetic and loses planar molecular orientation, "austenizes", and taking on an enlarged grain state. lower critical = stress relief = 850-1150*F depending on whether cast or rolled/forged (higher temps with worked steel), at which internal residual stress related to heat treatment or machining relief may be nullified. tempering = 200-1000*F, depending on desired ductility and hardness, with longer periods at higher temps resulting in extensive grain refinement which means lower hardness, with greater ductility annealing = second tempering for the purpose of reducing hardness for some specific purpose steels cannot be hardened without first pushing them into an austenizing grain enlargement stage (1655*F). quenching them in this state preserves the large grain state, leaving the steel hard and abrasion resistant, but brittle. tempering is all about grain refinement, which reduces grain size (allowing abrasion to increase), while increasing the bond surface co-efficient by increasing the total grain boundary surface within a specific volume of steel, so adding ductility and toughness.
Keith:: I am familiar with SS foil and have the scars to prove it. I did my Knife Blades using it and it worked fine for A2 at 1750-1800F My blades made from 154CM which goes off at 2150F had to be done in a vacuum furnace simply because the high temp burned the foil up! I was somewhat disappointed as my blades burned down with the foil.
Those blades had to be drawn back twice at 1000F to get the desired result of 62 Rc. Kind a bear to sharpen but they hold an edge forever. I have been using one as a deburring tool on my lathes for 25 years. it has only been sharpened once.
There is a lot more to Heat Treating than contained in my blurb above, but the basics are pretty much there.
Oh,,, and it's OK to disagree with me. I have found that anyone who thinks they really know what's going on, is probably full of,,, it. Myself included.
Randy
"It's not how well you do what you know how to do,,,It's how well you do what you DON'T know how to do!"
www.buchananprecisionmachine.com
I dont do much heat treating. My compression plug was easily hard enough already for my use. Made a floating expander ball for my 375 jdj and had to harden it. Just heated with a torch and tried a magnet on it til it wouldn't stick. Dropped in water. Glass hard!
FrankG:
Now thats something I hadn't thought of. Great idea.
Jack
I have been making dies from 7/8-14 threaded rod.
I got my first 6' in 2012 and my second this year, so I am using 3 feet/year
http://www.use-enco.com/1/1/26034-oi...-319-7908.html
It says 1010 to 1020 depending on rod diameter.
I often wish it were 12L14.
50CB? now that's hilarious. sublimely sarcastic, i assume.
Consider getting (local or mail order) a supply of hex and round steel in 12L14 alloy. It is a soft steel but do not let that fool you. For most of our needs it is plenty hard. Its value is in its ability to machine easily and produce a good finish.
Even used for case or bullet sizing dies, I doubt you will wear it out in your lifetime. And for some of us older guys that is not saying much !
Get some hex stock in 1/2" or 5/8" and then too some in 7/8" or one inch. I will post later why that is useful. Pros on this forum and long time machinists on here probably laugh at our novice ways but they have more experience and often more/better tooling and equipment. Any good advice is always helpful! BUT, some of the fun is figuring out how make something with what you have and/or making something you need that is not easily available.
Chill Wills
It's worth checking flea bay for 12L14 remnants. I got a large USPS flat rate box full of screw machine rems in 12L14 in 3-5" lengths that will probably last me a life time, and it was a fraction of the cost of virgin stock. Those short lengths are useless to a business, but perfect for home shop use.
I've made dies and inserts with round tops, knurled and with two milled flats for a wrench. On rare occasions something happens and I need to remove the die and on the knurled or plain round parts I end up with slip-jaw pliers scars on them. Factory dies too. The Hex stock in 12L14 steel is a simple fix for this.
The first pic is the hex stock in the lathe being turned down.
The second pic is the finished expander with only enough hex left to get a wrench on if ever needed.
This replaces a Redding expander in a three die set. The 38-56 Winchester. The old rifles of the vintage really were 38's with basically .380" barrel. Bullets in the .379, .380 or .381" diameter shoot well if the bore is in any kind of shape.
The expander that came with this .371 flared to .378" then + That will ruin a good cast bullet measuring .381"
The black expander above was replaced with the larger hex head expander and accuracy is great now.
-Michael
Chill Wills
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |