Full Transcript:
What’s up guys?!?!?! It’s Michael with Michael Talks Metal back for some more alloy steel talks today!!! 4140 is on the docket so sit down buckle up and get comfortable! Cause we’re off!
Next up in our new series on aircraft quality alloy steels is 4140. Like all 41xx series alloys, Chromium and Molybdenum are key to its performance. With a nominal carbon content of point 40 %, it is capable of higher strength and hardness than 4130. It can be heat treated to a hardness up to 50 Rc in sections 1/2 inch or less.
It is available in all common product forms.
Chemical Composition for 4140
| Chemical Composition | 4140 | |
|---|---|---|
| Element | Min % | Max % |
| Carbon | .38 | .43 |
| Manganese | .75 | 1.00 |
| Phosphorus | .025 | |
| Sulfur | .025 | |
| Silicon | .15 | .35 |
| Chromium | .80 | 1.10 |
| Nickel | .25 | |
| Molybdenum | .15 | .25 |
| Copper | 0.35 |
Small variations in these chemistry requirements exist in some specifications.
Typical End Quench Hardenability (EQH):
50 Rc @ 5/16″
44 Rc @ 9/16″
Typical Heat Treatment Temperatures:
Normalize 1600 – 1700 deg F
Austenitize 1525 – 1600 deg F
Temper 700 – 1300 deg F
We have several specs today so here goes with the more common specifications for 4140……
| Specification | Product Form | Quality | Melt | Condition |
|---|---|---|---|---|
| AMS 6349 | Bars | 2301 | VD | Normalized |
| AMS 6382 | Bars, Forgings, Rings | 2301 | VD | Annealed |
| AMS 6529 | Bars | 2304 | VD | Normalized |
| AMS-S-5626 | Bars, Forgings | 2301 | VD | See Spec – Various |
| MIL-S-5626 | Bars, Forgings | 2301 | VD | See Spec – Various |
| AMS 6395 | Sheet, Strip, Plate | 2301 | VD | See Spec – Various |
| AMS 6381 | Mechanical Tubing | 2301 | VD | See Spec |
AMS-S-5626 is the current replacement for the former military MIL-S-5626
As always, details in specifications and part requirements can alter what we have shown you here today. So for the 95th time – I won’t forget to tell you toooooo Check the Specs… Twice! This is Michael with Michael Talks Metal. Thanks for watching and if you stuck around till now, and haven’t subscribed, please click here. If you missed last weeks video, click here. Michlin Metals is a supplier and distributor of 4140 check the website for more info www.michlinmetals.com. Thanks for watching, I will see you next Thursday 10am. I’m out!
