Steel types are often mentioned when discussing quality vintage bikes and sometimes modern bikes. The big names in steel are Reynolds out of the UK, True Temper from the USA, Tange from Japan, and Columbus from Italy. Each brand has many different grades of steel.
Reynolds is one of the biggest names in bicycle steel and has a very long history. In 1902 they published their first bicycle tubing catalog. All their steels have a 3-digit number. As the number gets bigger, they will generally have a better strength to weight ratio. There are many other factors in frame design, so the steel doesn’t guarantee a great frame. But if you are shopping for a bike, manufacturers used the better steels for their best bikes.
520 and 525 are cold-worked chrome-moly steel. I believe they are the same, except the 520 is made in Taiwan. These steels have all the same properties as 4130 chromoly steels. This is sort of the bottom of better-quality steels.
531 is a manganese-moly cold-worked steel. It has been used for some mid and most upper-end steel bikes for a long time. Schwinn Paramounts used 531 steel for most of its history up until the 80s.
631 is a seamless cold-worked air-hardened steel.
725 is a heat-treated chrome-moly steel.
853 is a seamless air-hardened heat-treated steel.
931 is a precipitation hardening stainless steel.
953 is maraging stainless steel.
True Temper was the most known US manufacturer of bicycle tubing. I believe these were used for many Trek and Schwinn bikes. In 1990 they were bought by Huffy. They have since been bought by another company and stopped making bicycle tubing in 2017.
S3 Super Strength is super light, super strong, and super ride quality. Ultimate steel tubeset.
OX platinum was their strongest tubeset using aero-space grade air hardened steel.
Versus Heat Treated is heat-treated 4130.
Versus steel is stress relieved 4130.
Supertherm Steel is strong and lightweight for BMX bikes.
Founded in Japan by Yasujiro Tange in 1920, they have a long history of making tubes. Here are some of their tubes I believe listed from the best to the least good, the lightest are at the top:
Prestige Super Lite – high-tech treated double butted tubes for road racing.
Prestige – seamless double butted tubes for track/road racing.
Tange 1 – double butted tube for track/road racing.
Tange 2 – double butted tube for track/road racing/touring.
Tange 3 – double butted tube for heavy duty touring.
Tange 4 – single butted tube for touring.
Tange 5 – plain gauge tube for touring.
Infinity – double butted tube for road.
Tange 900 – double butted tube for road.
Tange 1000 – double butted tube for road.
Founded in Italy by Angelo Luigi Colombo in 1919. For a long time, they were the main competitor of Reynolds in Europe. They are now owned by Cinelli. These guys have had a lot of different tubes so here are a few of them:
SL – Super Leggera double butted OMNICROM alloy. Most famous Columbus tubing that competed with Reynolds 531.
SLX – designed for professional cyclists.
XCr – seamless, stainless performance tubing.
Spirit – triple butted OMNICROM alloy. Cold-drawn seamless tube.
MAX – triple butted OMNICROM alloy. Cold-Drawn seamless tube.
ZONA – all-purpose Hi-Resistance tubing. Triple/double butted 25CRoMo4.
Spirit HSS – high strength shaped.
CROMOR – double and single butted Cromor alloy.
1020 – this is an entry or maybe lower mid-level tubing.
4130 – many bikes will use just the 4130 chromoly labeling. It’s sort of the standard now, this is what Surly uses.
Chromoly – another sort of generic labeling, I believe these are usually some type of 4130. Often spelled differently. Cro-moly. Chrome-moly.