Chevy Connecting Rods - 4340? Use in tools/knives

Molly be damned steel can be a bitch to hammer weld. You've got to overflux it like crazy or you'll get an oxide skin with a fusion temp in the high 5000 degree range that will fool you into thinking that you've got a good weld ... until you put a load on it. Then there's hydrogen embrittlment, a well known but narsty characteristic of moly steels subjected to welding. There are easier car parts to work with, like springs and axles and tranny shafts. Good luck.

Charly

I'll put one through a weld, just to see ... :)

Charly the Bastard Spaketh Thusly:

Sorry to drift *slightly* OT, but what are axles and what are they heat treated to (if at all)? I'll be building a few gongs for high velocity centerfire rifles (.30-06, 7MM,

7.5 Swiss; all at 100,150, and 200 yds) and a lot of them use FMJ mil-surp for plinking. Would this stuff hold up? Standard 1/4" mild steel doesn't last long at all. I think have a source for the gongs themselves, it's the connecting hardware and swing arms I'm looking for. I plan on using leaf spring material (actual springs from a junkyard - probably 5160) as the actual hanger. Any suggestions appreciated, I think there's more knowldge of this in this group than anywhere else.

-- Bill H. [my "reply to" address is real]

Molon Labe!

Metallurgy teacher claimed 4140 (4130 etc) for axles but prob'ly something similar as opposed to being real 4140... is the way it usually goes with automotive stuff. :)

Don't know nuthin about axle's heat treating. :/

You need a real email address to post to rec.guns. (mine's hidden so it won't work)

Also rec.crafts.metalworking has a bunch of gun-gnuts on it. (decided to cross post it there)

Alvin in AZ

For a while, I imagine. Not a very LONG while, but a while...

Typical .30-06 "deer rounds" like Remington's 150 grain "Express" Core-Lokt PSPs will punch 1/4 and 3/8 inch mild steel plate like poking your finger through a piece of wet kleenex out to *AT LEAST* 100 yards that I can speak of from personal experience, and it wouldn't surprise me in the least to learn that they'll do the same at 150+. Use FMJ surplus rounds, and you can figure on it walking through the plate like it isn't there at all at any range that's reasonably practical to be shooting at. (Big surprise, since it's pretty much an armor-piercing round right from the git-go...)

Ditto the typical 7mm Rem. Mag, which I suspect is what you're planning on throwing downrange, but with an even longer effective range. I doubt there's any FMJ mil-surp around for that gun, though...

I have exactly zero personal experience with 7.5 swiss, but I'd bet on it being so close to a .30-06 (AKA 7.62) clone, performance-wise, that the difference is irrelevant for this discussion.

The two I know about personally ('06 and 7mm RM) and almost certainly the swiss as well, are some *SERIOUSLY* "heap-big medicine", suitable for taking anything from gophers (if you don't mind picking them up with a sponge...) to elephants. To get any "heap-bigger", you've pretty much gotta jump into the "Good god, man! That ain't a rifle, it's a man-portable cannon!" range. And let's don't even *THINK* about tring to keep a target from developing a severe case of "hazza-hole-innit-itis" for any length of time if somebody decides to break out with something exotic like a .50 cal! :)

Why am I not even *SLIGHTLY* surprised? Maybe 'cause I've personally punched through a V-8 engine block that someone left laying at about the

70-80 yard mark at the local range with my .30-06 and store-bought 150 grain Core-Lokt rounds on multiple occasions? Betcha the ones you've dealt with look a lot like a swiss cheese in no time flat, huh? :)

For rifle you want to use plate that is 500 brinnell hardness or better. Not cheap, and I know of no common "scrap" source for it. Hangers are an issue. Chain and cable don't last long. Using auto leaf springs as hangers is one I hadn't thought of.

the principle of armour is make the projectile hit the plate at an acute angle

couldn't you just make a 30/60/90 triangle of steel out of something like 4" plate?

everything would just ping off uprange.

And when hit, even a single leaf holds up surprisingly well, even to high velocity 6mm that punch thru mild steel with ease, and resists

30-06 class even better. I think OCS steel is upside of 350 on the hardness scale ** mike **

That's 52hrc.

Cool, now that, I can address. :) I read a book where "OCS" is

44 to 48hrc as a "target hardness" and that's 420 to 460 brinell.

Don't leave out the coil springs and anti-sway bars as being the same stuff as the leaf springs, ok?

210 paces with 52 and 53 grain hollow points from a 22-250 would make a crater in mild steel like what was being described for 30-06, IME. But I have no experience at all, -not hitting;)- the 4"x 6"x 3/4" plate and hitting the chain with that 22-250. :)

Alvin in AZ

don't know about shooting at a leaf spring. You might get an elastic impact where bullet fragments are bounced back at the shooter.

T> > Sorry to drift *slightly* OT, but what are axles and what are they

T-1 works fine for pistol and cast lead rifle, but it doesn't last long under FMJ rifle fire. Hi manganese steel is used in crushers as wear plate. Interesting stuff, soft and kind of gummy to machine, but it impact hardens nicely. No idea how it would hold up under fire. Anybody live near a ship breaking operation or military scrap yard? Armor plate might be available. Some of that stuff is TOUGH.

Cool website ...but what's the composition of those two steels?

A couple years ago worked at getting the composition of T1 (not the tool steel;) and couldn't find a thing. :/

BTW, "heat treated grade 5 carriage bolts" are known in "the bolt trade" as "shaker screen bolts". Been there, bought those. ;)

Alvin in AZ

According to Guy Fawkes :

I'd feel happier about having it angled so the pings went

*down*, into a sand pit.

Enjoy, DoN.

Does that really happen?

I know you can get a 22RF to turn around and "come back at you" when shooting a railroad rail from the side. We heard about that one and

-shooting at an angle- got some bullets to "turn around and come back" sure as heck. Using the "web to base" curve and the "web to head" curve to turn the bullet 90 degrees, twice.

Our test method in an ascii birdseye veiw... :) _ is a piece of rail,

^ is the bullet path... _ us^ricochets

A guy could get to where almost every shot resulted in a "turned around bullet" after a little experimenting.

Alvin in AZ

R, Tom Q.

Cool thanks! :)

Alvin in AZ

T1 holds up just fine to high velocity rounds. Metallic Silhouette targets are usually made of that. about 3/8" I'd guess. My .308 bolt pistol with a 14" barrel will leave little pock marks on the target but nothing on the backside. The more common 7mm x XX doesn't even pock mark it.

The >> T1 plate is often used at the bottom of rock crushers and sifters.

The guys who make em in this area, tell me that stainless steel mig is the way to go. I blew the feet off all the chickens I have using my

357 Herrit, so used some stainless rod, and they seem to be holding up.

I dont remember what the ss alloy was.

As for T1 not holding up..Ill have to beg to differ. Shrug

Gunner

"A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences."

- Proverbs 22:3