badfishgood

I am looking at a vintage Nishiki steel frame bike. I am trying to figure out what kind of steel was used for the frame. The only identifier is a sticker that reads moly-bdenum. I can't find anything on this steel. Anyone have an idea what quality this steel is?

The frame is an olympic royale, made in japan. Thanks.

TimJ

It's chromoly of some sort. I think the whole name for chromo is chromolybdenum so it's chromo. I've been told chromo "starts" at about 4130. That is, for something to be considered chromoly it's basically going to be 4130 chromo steel. I don't know if that's correct, but the frame is most likely a base chromo.

nlerner

"Chromo" is short for chromium molybdenum. Here's a good primer on what the numbers mean: https://www.desperadocycles.com/The_L...bing_page1.htm

Neal

bikingshearer 

It could also conceiveably be a manganese-molybdenum steel alloy, which, if memory serves, is what Reynolds 531 was. I have no clue what the advantages/disadvatages of manganese vs. chromium in steel alloy tubing. All I know is that 531 was the gold standard for a long time and is still good stuff (even though Reynolds isn't making it anymore.) Many builders still used it for fork blades long after the "super steels" had become commonplace.

reverborama

That's a high quality steel. Sheldon has a nice page describing the various materials:

https://www.sheldonbrown.com/frame-materials.html

badfishgood

I see no mention of moly-bdendum on the page you referenced

I am trying to figure out how this steel compares to 531, Tange 1, Tange 2, et cetera.

Bill Kapaun

"I see no mention of moly-bdendum on the page you referenced"

Naybe bekaws it's speled molybdenum?

Actually, I don't see moly mentioned either

Here's a list of steel "numbers"

https://en.wikipedia.org/wiki/AISI_steel_grades

TimJ

AISI steel grades: https://en.wikipedia.org/wiki/AISI_steel_grades

Molybdenum Steels
40xx Mo 0.20% or 0.25%
44xx Mo 0.40% or 0.52%

https://en.wikipedia.org/wiki/Molybdenum

So it's steel with just Molybdenum

old and new

Read what nLerner states as well as TimJ. I have'nt looked at the recomended sight,I don't need to. Your Nishiki, the one that i'm SURE in on e-bay,everything is e-bay related here, is made from Japanse CHRMLY tubing'd main triangle. 4130, Tange, ishi, MIY, 520,531.631 on and on is chromalloy,spell it as you want.One member mentioned Magnese, GOOD point,it's not that,that is a Reynolds TYPE of chromalloy.. It has no chromium,more magnesium instead,as well as silicone,steel etc. Reynelds made 753 'till recently. 753 was the mag. type. Your bike is NOT high tensile,the fork will say 1024,1024 is technically a high-tens. steel. DO bear in mind that the difference between 1024 and 1020 reynolds and CRMLOY is just a few molecules. Nishiki sold that bike for 3 to 4 bills,maybe(probably) more,depending on the year.I road saw, and worked in a store that sold dozens of Nishikis,this co. was involved in Holland and other Euro. nations bfore and after it was in the USA.

OLDYELLR

This is the decal I see on my Nishikis.

"Double butted chrome molybdenum tubing" No idea who manufactured the tubing.

Chrome moly was a widely used high strength alloy steel tubing, not to be confused with Reynolds' 531 manganese molybdenum, but similar.

T-Mar

The only Olympic Royales I've seen were from 1978-1979. They were chromium-molybdenum, plain gauge, main triangles (likely Tange #5 or equivalent) with hi-tensile forks and stays.

poopncow

The manganese allows for heat threatment to a higher tensile strength without getting brittle.

4130 is meaningless, because in normal state it is no better than a good structural steel. The tensile strength after heat threatment is what makes the difference. And that can vary greatly depending on the process employed. The same piece of C'moly can be made to exhibit totally different tensile strenghts and characteristics depending on the heat threatment.

again 4130 is the alloy, after that, it is meaning less