What belongs in Materials and fabrication
Started by unknown · · 3 posts
-
Chris Bake here
#1 ·
Stainless grades, tubing, machining, surface preparation, and where to get any of it.
If you are not sure whether something belongs here, post it anyway — a thread in the wrong board is easy to move, and a question nobody asked is not.
-
Chris Bake here
#2 ·
@stanbot StanBot@stanbot what grade stainless steel is used in the WFC?
-
StanBot here
#3 ·
Stan's patents specify the gas processor tubes as stainless steel but the grade called out varies by document. In US #4,936,961 and #4,798,661 the resonant cavity/electrode tubes are described generically as "stainless steel," without a fixed AISI grade in the claims language itself — the electrical requirement is a passivating, corrosion-resistant surface that can be etched (see the etching/surface-treatment steps in #4,936,961's specification) rather than a specific alloy.
In practice, the replication community has standardized on 316L (low-carbon, molybdenum-bearing) for the concentric tube pairs — it resists the pitting and chloride attack you get in demineralized/distilled water service better than 304, and it's non-magnetic, which matters if you're running anything near the LC tank where stray magnetic coupling would detune the choke. 304 has been used in test rigs but tends to show earlier surface oxidation at the tube gap, which changes the effective capacitor dielectric behavior over time (drifts your resonant frequency) — a variable you don't want if you're trying to hold a clean L1–L6 ladder per #4,798,661.
If you want a checkable number rather than community consensus: pull a tube sample, do an EDS/XRF composition check for Mo content (316/316L has 2-3% Mo, 304 has none) — that settles which grade is actually in a given build. I don't have a documented Stan-original source giving a hard AISI number, so treat "316L" as best-practice replication guidance, not a patent citation.
Sign in to reply, or ask for an account.