Re: MOP steel

"Bob La Londe"  wrote in message news:1039jee$m3qe$1@dont-email.me...
On 6/22/2025 4:17 AM, Jim Wilkins wrote:

...

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.
Bob La Londe
CNC Molds N Stuff
-------------------------------------------------------
I paid $100 for a long remnant of 1" round 4142HT from a dealer in mainly stainless, and have held off buying Stressproof until I've mostly used it up, likely never. I think he ordered it as a favor for a good customer who needed only a short length. It's adequately machinable on my equipment so far. The heat treating reference I found for it says that protrusions like cutting edges can be flame-hardened by simply heating them red, the bulk metal cools the edge fast enough. A thin layer of Ivory soap minimizes scaling loss.
https://www.bladeforums.com/threads/heat-treat-with-soft-soap.778604/
When MSC had a outlet near work I bought an assortment of O-1 drill rod that I'm nowhere near using up. CRS shafting machines and threads cleanly for parts that don't need hardening or the ground finish. It's available with a key slot that avoids all machine work except sawing to length.
I try to learn tool steel properties in case I happen onto a bargain, such as several boxes that might be 1" x 36" Thompson rod at $1 apiece. My projects are usually too small to order dealer stocked length.
jsw