CM marked bullet guides

[Frank Smith]

The Boak memo is dated February 25, 1942.

Thanks much, Bob. Appreciate the quick reply.

Your tools were more likely Amola steel that WRA also used because it was pushed on them as a substitute.

Most tool makers used the "National Emergency" (also called "War Department") steels that metallurgists at AISI, from industry, and the WPB created in collaboration with each other as a result of the WPB cutting chromium and molybdenum content at <0.6%. These were AISI 86XX, 87XX, and 92XX triple alloys that used <0.4% nickel, chrome, and molybdenum. (Some makers, most notably Herbrand, actually forged-in the AISI numbers on their wrenches. Others went with the more generic "Alloy" or no markings at alll.) Other mfgrs used manganese steels (AISI 13XX). And others just perfected carbon steels.

Amola was developed by metallurgists at Chrysler and was being touted as something of a wonder metal. It was also a chrome/moly alloy but with different proportions. Chrysler made a lot of car springs out of it, even featured it in some magazine ads.

Do you have any technical references for Amola, Bob? I've been unable to find anything definitive that provides its chemical composition or AISI grade number. What is your source for identifying it as a chrome-moly steel? If it was indeed a chrome-moly, it had to be a low-chrome chrome-moly, which is AISI 4118, 4120, or 4121, which all had <0.6% chromium content. I have been unable to determine when those grades were created. If I can link them to Amola, that would be a big breakthrough for us, as Ford and Willys documentation both refers to "Chrome-Molybdenum" steel well into 1943, which has confused us, since we know that the WPB restricted high-grade Chrome-Moly (AISI 41XX) after January 1, 1942. Anything you could point me to that provided Amola's formula would be much appreciated, Bob.

[Frank Smith]

Quick additional comment: The one puzzling thing about the Boak memo is the implication that the "#3115" steel on order was a substitute for the chrome-moly. AISI 3115 steel is low-chrome (.55%) but high nickel (>1%). Nickel was also capped at <0.6%, so I can't figure out how AISI 3115 nickel-chrome steel is a substitute for AISI 41XX chrome-moly steel. Unless WRA had an A-10 or higher priority rating from the ORD. But if they had that, getting and using chrome-moly steel shouldn't have been a problem. So I'm still puzzled.

[Bob Seijas]

Tony Pucci solved the CM mystery and wrote it up in the Winter 2006 GCA Journal. He had both CM and A-marked WRA parts analyzed to confirm it. In the Fall 2010 Journal Bruce Canfield expanded on it from the Pugsley files, including this:
Amola was a relatively low cost steel that was extremely competitive in price with various other types of alloy steels and had greater availability at the time. Despite its comparatively low price, Amola was a high quality steel with a very fine grain that required no imported alloys. The Chrysler Corporation developed Amola steel and used it extensively in the manufacture of its Dodge and Plymouth line of automobiles, including the top of the line “Airflow” models...

I hope you can read the details in this photo of the analysis.

[Frank Smith]

Thanks much, Bob! No problem reading it with the 'expand to normal size' feature. I'm assuming the part made with Amola steel is the #3-C bullet guide marked with an "A." (Incidentally, Fairmount made wrenches marked with an "A", and we've assumed it was Alloy. Might have to relook.) That is an odd composition. A moly-chrome with very low chrome content. I don't think there is an AISI/SAE grade that matches it precisely. Something lower than AISI/SAE 4021, which is the grade of the unmarked #4-D moly-alloy bullet guide.

Can you give me some approximate date ranges for the parts that were tested? Did WRA stop using the nickel-chrome-moly sight base and the chrome-moly aperture, clip latch, and hammer? If so, when? And what did they replace them with? Amola steel for those parts as well? Or was the Amola and the moly-alloy steel only used to replace the #2-B chrome-moly bullet guide?

[Bob Seijas]

I don't recall the dates, but CM and A parts were only used until they could get the normal steel. The WRA mavens on the board can give you chapter and verse. WRA clearly had some left over when they finally got the regular steel, because we see them again at the very end of production when they were sweeping the floor to use everything up.

[Redleg]

Since I am prominent in the older posts, I am now playing the musical themes to the Twilight Zone and the X files; the truth is out there now.

I am also quite convinced that Continental Machine and Alcoa had no part in the A and CM stampings, nor did aliens provide the steel , no matter what Childress and Psoupolokoupolous say on NatGeo.

Reading those old Chrysler Ads featuring Amola steel for their auto springs, is entertaining.