I've never seen this asked before:

What metal are the body shells made of?

I want to say aluminium, as it wears to silver where the bottom plate is removed 100's of times. It could be magnesium too, I guess.

I took a graduate level corrosion course years back, but don't use it much, hence the ignorance. If the body shell material, as a result of normal wear or maintenance, comes into metal-to-metal contact with zinc or brass top and/or plates how much of a galvanic current is going to be generated? And if this area gets moist from the environment, which will corrode faster (sacrificial anode).

-- chris chen (chrischen@msn.com), March 20, 2002

Answers

Sorry, I tried hitting the stop button to make corrections; I see they went through anyway. Please Delete Tony; it lokks awful.

-- chris chen (chrischen@msn.com), March 20, 2002.

See the various topics in the nemeng.com/leica faq.

Generally speaking, the latter M4-P's and all production run M6s are made from Zinc Alloy. The M3, M2, M4-2, v.early M4-Ps, and M7s are made from brass.

-- Andrew Nemeth (azn@nemeng.com), March 20, 2002.

Andrew,

I love your site. But the question is about the body shell, not the top or bottom plate.

-- chris chen (chrischen@msn.com), March 20, 2002.

All the M body shells have been made the same way, a hard-drawn aluminium alloy shell encasing a die-cast chassis. Apart from the late M4-P's and all M6's (excluding M6J and painted M6 specials) all top plates were brass. ALL M baseplates are brass. The M7 has seen the return to brass top plates.

-- Giles Poilu (giles@monpoilu.icom43.net), March 20, 2002.

Chris, for more on this subject try and get hold of a copy of "A History of the 35mm Still Camera" by Roger Hicks, it's a fascinating book and goes into great detail on the evolution and construction of the Leica amongst others.

Some of the most gratifying text is the comparison of materials used, typically:

"Let us now look at the materials and connectors used for flash mechanisms. Although some of the lesser makes got away with copper and brass, almost all the better ones used some sort of precious metal plating, usually gold, to guard against oxidation of contacts. Leitz, of course , went one better and used solid platinum - iridium (!) in the M2 and possibly M3, solid 80 per cent gold elswhere."

Judging by the M4-P sync. problems maybe they forgot about this then!

-- (giles@monpoilu.icom43.net), March 20, 2002.

Good point - because you spoke of external wear I had mistakenly assumed you meant the outer casing, not the interior frame.

The interior frame is alumninium alloy. What type, I don't know. Don't know the likelihood of the frame corroding either (although I suspect it wouldn't as it is too protected with clading or paint).

-- Andrew Nemeth (azn@nemeng.com), March 20, 2002.

Actually - I asked a Leica rep today and SHE said the main casing (the heavy flattened metal 'tube" that's covered with vulcanite/vinyl and holds the shutter box and film inside it) is steel.

FWIW.

-- Andy Piper (apidens@denver.infi.net), March 22, 2002.

So, Chris, what's the corrosion potential . . .

. . . if it's aluminum

. . . or if it's steel.

No corrosion noted on my M2 after 40 years (brass top plate).

-- Bob Fleischman (RFXMAIL@prodigy.net), March 22, 2002.