12L14 Holee Kowww
- Thread starter alinwa
- Start date
GeneT
Active member
You sure you've got 12L14???
I have not found threads in 12L14 to strip out any more readily than those in mild steel. "What to you is moderate tension" is meaningless and condescending - threads have torque specs. Ignore them at your peril! That said, I've had no problem torquing male or female 12L14 threads to spec. I have certainly not seen any of it moving about "like modeling clay". If I drop a piece on the floor it bounces and clangs like most steel. In fact, aside from machining, or a spark test, I'd be hard pressed to separate it from 1018.
I'm not sure what you have, and it's probably not what I'd make a brake out of in any case, but from your description it's not free-machining steel - it's lead!
GsT
Very interesting.....
Jackie thrives in a world where engineering limits are tested daily. Where welds will rip out by the roots and shafts will twist and warp if not fully stable. I live in a construction atmosphere where if a weld breaks on a dozer you just crank up the heat, buy a couple more bundles of stick and pour more metal into the gap......stability via the brute force approach
Which leads me to my conundrum.
I'm using this 12L14 to make prototype muzzle brakes for a couple big guns. Guns that will break ME if a brake fails.
First thing I notice is that the threaded portions strip out easily. That I'm stripping out 1/4-28 grub screws under what to me is moderate tension. Second thing is that deflection both pushing and pulling is a thing........ this stuff machines like butter and moves about like modeling clay.
Drop a piece on the floor and it dings like lead.
Instead of making these brakes as light as possible I'm tending to leave extra meat in the high-stress areas...... let's hope I'm leaving enough!!
I have not found threads in 12L14 to strip out any more readily than those in mild steel. "What to you is moderate tension" is meaningless and condescending - threads have torque specs. Ignore them at your peril! That said, I've had no problem torquing male or female 12L14 threads to spec. I have certainly not seen any of it moving about "like modeling clay". If I drop a piece on the floor it bounces and clangs like most steel. In fact, aside from machining, or a spark test, I'd be hard pressed to separate it from 1018.
I'm not sure what you have, and it's probably not what I'd make a brake out of in any case, but from your description it's not free-machining steel - it's lead!
GsT
well I bought a 244lb stick of it from Pacific Machinery and Tool Steel so I HOPE it's the right stuff
.......powderbrake
Member
12L14 has a yield strength of 60,000 psi. It is just "mild steel", but we tapped all sorts of holes in it, and never had a problem with customers stripping threads.
It was our go to material (primarily for it's free machining properties and its magnetic properties), and we used it for shafts, rotors, brake stators. Nothing of these required high material strength. Many of our units were steel or ductile iron castings, or 17-4 investment castings for load cells, but we tried to use 12L14 as much as possible.
It was our go to material (primarily for it's free machining properties and its magnetic properties), and we used it for shafts, rotors, brake stators. Nothing of these required high material strength. Many of our units were steel or ductile iron castings, or 17-4 investment castings for load cells, but we tried to use 12L14 as much as possible.
jackie schmidt
New member
Leaded steels are simply steels that have lead added at at the pour. The lead literally gets between the individual molecules of the parent metal. This is what gives these steels their free machining quality as the lead acts as an internal lubricant.
The major drawback is ductility suffers. One of the key factors in determining a particular steels ductility is the actual cleanliness of the steel at the molecular level.
In Leaded steels, and some high sulphurized steels, the lead or sulphur literally gets between the molecules of steel, not as a chemical bond or alloying agent, but as a simple mechanical bond.
This is fine in applications where ductility is not a major issue. Leaded steels are rarely recommended in applications where the parts will be subjected to shock loads while under stress.
The major drawback is ductility suffers. One of the key factors in determining a particular steels ductility is the actual cleanliness of the steel at the molecular level.
In Leaded steels, and some high sulphurized steels, the lead or sulphur literally gets between the molecules of steel, not as a chemical bond or alloying agent, but as a simple mechanical bond.
This is fine in applications where ductility is not a major issue. Leaded steels are rarely recommended in applications where the parts will be subjected to shock loads while under stress.
Watch out for the Rust though!
Hey guys, I work with a lot of 12L14 and other alloys in my shop and love how easy it is to machine as well. BUT, do be sure to finish the surfaces afterward. It will rust over very quickly with any moisture/humidity. I find a cold blue treatment keeps the rust at bay pretty well. Unlike the other alloys in my rack, I don't have to worry reading labels on the 12L14 stock, it is always the brown pieces haha!
Hey guys, I work with a lot of 12L14 and other alloys in my shop and love how easy it is to machine as well. BUT, do be sure to finish the surfaces afterward. It will rust over very quickly with any moisture/humidity. I find a cold blue treatment keeps the rust at bay pretty well. Unlike the other alloys in my rack, I don't have to worry reading labels on the 12L14 stock, it is always the brown pieces haha!
So True!
I just got my order of horseshoe nails from the brown truck yesterday...... be rust-bluing me some Leadloy