On 6/22/2025 4:17 AM, Jim Wilkins wrote:
strength of granite is given as up to 45,000 PSI. Single point carbide
tipped chisels are recommended to carve it, carbon steel chisels for
other types of stone dull in seconds on it. The rock drill rod I turned
the jack adapter from is a broken and discarded end with the 3" drill
bit still on. 1/2" carbide buttons worn hemispherical do the cutting/ pulverizing, with compressed air removing the dust.
"Eglin steel can be welded easily" but machinability isn't mentioned.
HSS cuts Grade 8.
My two miracle steels (other than various stainless) are 4140 and 1144.
4140 has an edge on corrosion resistance due to some chromium, but not
enough to be consider stainless.
1144 has a huge edge due to machinability, but it seems to be only made
in hex and round.
4140 is machinable, but tends to work harden unless you take fully
engaged cuts with no rubbing.
4140 is somewhat touchy to weld, but with preheat welds nicely.
1144 tends to hot short when welded. (Crumble or turn granular and
crumble if I understand correctly.)
Both are forgeable, but I'd forge 1144 at the lower end of the forging
range. I have forged 1144 at bright red, but not orange heat with good results.
Both are pretty strong in the annealed state and may be used for many
tough applications. I tend towards 4140QT TGP for precision shafting,
and if its very low corrosion environment, and I need to turn journals
I'll go to 1144.
I tend to use 1144 more than 4140, primarily because its locally
available. I have to order 4140.
Subjectively I would say even in the annealed state 4140 has higher "toughness."
I believe both 4140 (certainly) and 1144 can be heat treated, but I
would check the ** ASM Heat Treater's Guide Companion. 1144 may
require a little more care due to its tendency to hot short.
If I need an easy mid carbon heat treatable I'd probably pick 1045.
** Unfortunately in the predominate abusive rapist mentality that seems
to permeate the tech sector like an incurable virus, the ASM Heat
Treater's Guide Companion APP no longer appears to be available through
the Google owned Play Store. First you are forced to create a password
to approve payments, and then what you want can not be found. I have
not checked F-Droid, but F-Droid seems have little new to offer as of
the last time I checked.
--
Bob La Londe
CNC Molds N Stuff
--
This email has been checked for viruses by AVG antivirus software.
www.avg.com
--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)