Mc 20 Head shroud

[Ronald Cubel]

Have seen both tags on original shrouds, the plate was glued to the shroud not riveted. 4000/400 series stainless is magnetic. ron

[ted johnson]

Steve, I didn't mean to say that the non-magnetic alloys are inferior! It's just that some of the 13-8 PH, 17-4 PH, 15-5 PH alloys, Etc. that are ultra corrosion resistant are magnetic. Some of the very good alloys we commonly use are non-magnetic, even the alloys we used at Sandia for spacecraft.
I, too have never seen a riveted Mc20 label! All mine were sticky-back. It was always the first thing we did- to remove the labels so the shroud looked nicer. This is a fun thread! Ted

[Tom Smith]

Sounds like some of the Mc-20 head shrouds were made from the same stainless they used for outer covers on certain saw mufflers and handle braces etc. The stainless they stamped the triangle point covers from is non-magnetic.

[vince hughes]

Many stainless alloys, some magnetic, some not. Some will actually rust! oh that hurts. I dont know Jack about alloys, but been around the hot rod/hot boat industry too many years, and 2nd hand hear about this stuff. 300/400 series, ones mag, one's not. My theory, Mac tried to get the SS head shroud to shine, or maybe in the interim before the flash chrome top were available? I passed on a very early 20 from a Mac enployee that was all yellow, with sticker, probably nos.(hundred bucks) I think it went to Thurman in Tx., and then to Holland.
if it dont go... chrome it
I dont know JACK,
signed JACK

[Carl Haydt]

Here's a pic of the riveted on tag. The shrouds appear to have been flash chromed as the finish is on the inside of the shroud as well. I think the "whatever McCulloch wanted to use at the time" theory is right on. Actually I'm kinda glad they did this! 45+ years later and those guys are still entertaining us by keeping us guessing on what we have! Carl