Mid-year tailpipe extensions; magnetic or not?

[Gary B.]

Are there any owners of mid-year cars out there whose cars have the original tailpipe extension? The JG says these are stainless steel and hence I thought would be non-magnetic. I bought some vintage NOS GM extensions, part # 3819573, which I assume are the correct parts (they came in vintage GM boxes and they have the stamped part number and the weld seam), but it turns out they are magnetic. I can't say if they are very magnetic or only somewhat magentic, but a magnet sticks. Can someone with original tailpipe extensions check with a magnet and tell me if original mid-year tailpipe extensions are at all magnetic?

Thanks in advance,

Gary

[Ed D.]

Re: Mid-year tailpipe extensions; magnetic or not?

For what it's worth.... I just took off the old muffler system that was on my car. The car has 65k original miles. The second owner says he bought the car in 1970 with that system on. The tail pipe extensions do hold a magnet. ...Ed

[Joe R.]

Re: Mid-year tailpipe extensions; magnetic or not?

Gary,

If you get a horseshoe magnet close to them, it will jerk the pipe right off the Vette.

They are not a very high grade of stainless.

Regards,

JR

[Gary B.]

Ed, J.Ray: Hmm... Very interesting; How to judge?

Ed, J. Ray,

If the tailpipe extensions are stainless, but nonetheless magnetic, what do people base their assessment on when judging? Presence of the weld seam?

Regarding the stamped part number, I seem to recall a posting thread not too long ago in which several people said that original extensions do not have a stamped part number, while GM service replacement parts do?

Do the ones on your cars have the part number stamped into the extension, near the forward end?

Thanks,

Gary

[Ed D.]

Re: Ed, J.Ray: Hmm... Very interesting; How to jud

Gary... I looked for a part number and could not find one. They are back on the car, so it is possible I could have missed it. I do know that the nice stainless exhaust tips that came from Allen's exhaust are not nearly as magnetic as the old ones. When I put on the new Allen exhaust system I decided to put on the old exhaust tips for nostalgia .... even though they are not nearly as nice as Allens!

[Gary B.]

Less magnetic alloys

Ed,

I'm wondering if the dogma that stainless is completely non-magnetic has led to the repro sources using a less magnetic alloy of stainless in order to satisfy customer who think that the originals were totally non-magnetic.

Gary

[Joe R.]

Re: Exhaust Extensions & Part Numbers

Gary,

I have several original sets of Exhaust Extensions that I have removed from Vettes for the last 40 or so years. Not one original I have removed have a part number on them.

All extensions in the box from Chevrolet have the part numbers stamped on them where the clamps should be.

Regards,

JR

[Ed D.]

Re: Less magnetic alloys

Gary ... I went out and pulled the exhaust tip off the car. No part number and like J.Ray mentioned very magnetic. The Allens exhaust tip has just the very slightest magnetic pull.(just slightly more then my stainless refrig.)..Ed

[Len Rayca]

Re: Mid-year tailpipe extensions; magnetic or not?

Gary: There are ywo type of stainless, Austenitic ans Martensitic. The Martensitic type of stainless is magnetic and probably the type used on the extensions.

[Gary B.]

J.Ray; no numbers, but a weld seam?

J.Ray,

Do your originals show the weld seam? I'm trying to figure out what I should be looking for when judging.

Gary

[Joe R.]

Re: J.Ray; no numbers, but a weld seam?

Gary,

Yes, there is a weld seam and it is directly on the bottom on each and every set of old extentions I have. About 4 pairs and they are exactly the same.

Regards,

JR

[Ed D.]

Re: J.Ray; no numbers, but a weld seam?

Gary... I agree with J.Ray ... a seam on the bottom. ..Ed

[Gary B.]

Len, do you know the stainless series?

Len,

Do you know what series of stainless the exhaust tips are? Are they the 430 series like some of the ignition shielding?

Gary

[Len Rayca]

Re: Len, do you know the stainless series?

Gary: First i apologize for the typos in my previous response. Second, I am sorry but I do not know if they are made of the same stainless as the shielding.

[Mike M.]

Re: Len, do you know the stainless series?

Gary,
430 Stainless Steel and generally all of the 400 series of stainless steels are martensitec family of SS and in the old days refered to as "chrome - iron". They are a combination of carbon steel with Chromium added in a range of 11.5 to 15% (plus approx. 2% other metals). Therefore the material will be magnetic as it is mostly carbon steel. The 300 series stainless steels (austenitic) contail steel, chromium and nickel. The total content of steel in 300 series will run between 30 to 40% and for the most part is non-magnetic. Some of the cheaper types (301/302) can test magnetic (usually slightly), but type 304 (in the old days referred to as "18-8" for the percent Cr and Ni contained) and higher numbers usually will not test magnetic. Don't know if this helps and what I have stated is VERY general, but is typical for the type materials mentioned. I do not know what types of SS are used for what purpose on Corvettes. For the most part, 300 series is more mallible than 400 series and is used for more intricately shaped items made from thin sheets. 400 series is harder and can be hardened for high quality cutlery. 300 series does not make good knives.
Mike