Identifying tubing from Frame Weight

[GrubbyJohn]

Does anyone know the difference % wise of frames made from Accles & Pollack Cro Mo, Reynolds HM, Reynolds 531 plain, & Reynolds 531 butted, or cheap seamed carbon steel please.
Trying to establish as to whether you can identify what type of tubing might have been used on old 50's,60's frames when there are no markings left ?

Are there any other ways of identifying them other than a tame metallurgist !
Many Thanks

 

[keithglos]

Re:

Most butted 531 frames from the 50s /70s had a seat tube 20/23 g. With outside diameter of 1 1/8 inches, this makes the saddle pillar/seat pin now 27.2mm diam.

Some top Italian frames had a sleeve inside the seat lug making inside diam 26.4. With this you would never get a stuck seat pin.

So you can calculate tubing guage from inside diameter.

Keith