I suspect that your manually intensive process is way more of the problem than the bolt material.
I have machined thousands of bolts for all kinds of products and tooling in my early manufacturing career as a machinist. I spent about 10 thousand hours running mostly turning machines of all type and did not run into noticeable hard spots in any material except when machining 4140 in areas where it had been welded.
I also ran into hard material when a dull drill work hardened a piece of 300 series stainless steel. But that is not a fault of anyone but the machinist.
It was rare to run into what you describe in quality bolts. Do yourself a favor and buy a lathe. You will enjoy your metal projects a whole lot more.
EDG
If the material itself is low carbon steel it would be possible to add coal to the surface so that it is possible to harden it afterwards. If there is no need for fancy case hardening one could put the parts and coal dust to forexample piece of cast iron or steel pipe that is possible to close air tight.
After that heat it up to 1600F and keep it there for several hours. After that drop the parts to water for quenching.
Not the quickest way but works if there is no other options.
S
Pritty handy if one wants to DIY forexample swaging dies. Just needs to drill the holes for core swage and core seat dies, polish them and make punches.
Pointing die requires little bit more work as one needs some kind of reamer that shapes the cavity according to the required shape. D reamers are relatively easy to make and works in manual lathes expecially if the roughing is done forexample by stepdrilling the cavity beforehand.
Forexample Midway has plenty of options starting from blank to different kind of predrilled blanks.
In predrilled you already have hole in it so it is easy to open it up with bigger drill or reamer if nesessary.
As the blanks are under 30 bucks a piece the complete 3 die set would cost under 100 bucks.
Of course there is the work included, but one could always say: "I MADE IT!"
S
PS. Almost forget to mention that in Midways page they give instructions for heat treatment also. That steel was very simple to harden.
Last edited by seppos; 12-29-2016 at 07:15 PM.
Ruffstuff has exelent selection of rod end plugs and nuts that fits the 7/8 14 threads.
Cuts the needed work with the die making.
http://www.ruffstuffspecialties.com/catalog/78REPARTS.html
S
The problem with the regular threaded rods are, that the are made from cold draw steel. This is to the reason that it is cheaper and easier to work with. Most of the threads are made by rolling. That requires considerable amount of force, and is harder for the tools so mostly it is easier to use softer cold rolled steel.
With harder steels it is common to make the thread by cutting.
How to tell difference is it cut or rolled thread?
The pic above tells the difference: in rolled one the upper edge is square, as it is made by the side of cutting tool. With rolled thread, the edge is round, as it is formed by the pre shaped forming mandrel.
As the material is inferior in the cold draw steel, the rolling is also better as it changes the grain structure of the steel. This applys to the thread but does not change the steel deeper.
As the low carbon cold draw steel would not harden or harden only little, if one wants to harden the surface it should be case hardened or nitrited. In the process the surface could be transformed from.. lets say 30 HRC to 60 HRC. From the surface one can not say if the steel is 4140 or low carbon, as the surface in both steels could be brought to same hardness with the same treatment.
Cost of such treatment is not very much. Normally they charge by the weight. There might be minimum amount that they treat, but sometimes they take smaller parts to treatment with small price so that they could fill the patch and start prosessing. It is economical to have the oven full instead of treating small patches.
S
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 |