What kind of steel in the frame? kz750 E1 1980

Hi I just noticed that I have a frame tube that is bent on my bike.
(probably took a turn whit the side stand down)
Anyway it is the tube going under the engine where the side stand attaches.
(I wish I had took some pictures of it)
Anyway the piece of steel where the side stand attaches is rotated upwards (I belive this should going straight out from the frame horizontally not pointing upwards.
They have rasied the pedals on this bike and the shifter as well and still I hit the side stand mount while downshifting.
and because of the piece of shit shifter linkage (probably home built) I have to lift my foot of the pedal to upshift.

And the frame tube I belive are supposed to be dead straight in this area have a nice curvature to it (side stand pushed in slightly)
that bugs the hell out of me.

The thing is I don't have a clue of what kind of steel is used on these old bikes.
and since I have a little to many years practice whit different metals I'm not one to take chances.
(some alloys are just fucked up,)

So I wonder do anyone know what alloy of steel the frame is built from?
For example will it tolerate being heated to cherry red and straighten ?
(some alloys will lose nearly all of it structural strength doing something like that)
or will it in fact harden and be like a piece of glass afterwards?

Will it tolerate being straighten while cold or will it crack?

And furthermore, since one tube is already bent and I'm planning on tearing down the bike completely after this season I would like to check the frame for straightness how would I do this whitout a frame jig?
what are the measurements I should take and what should they be?
and how much tolerance for error?

Best regards H

Someone more knowlegeble than my self will certainly chime in, but I am pretty sure I remember reading here somewhere that they are made of plain mild steel.

Always heard it is mild steel.... whatever that is.

Mild steel = low carbon steel
Tool steel = high carbon steel, ( drill bits, taps, etc...)

Ultra low carbon steel = anything from china :woohoo:

.

Mild steel/1053 /glorified water piping . :laugh:

PLUMMEN wrote: Mild steel/1053 /glorified water piping . :laugh:

Ive heard of people using the black water pipe for frame work.

If I ever saw anybody using actual water pipe for frame mods Id want to stay back 1/2 a mile from them while they were riding. :laugh:

ASTM A 53 stell pipe. AKA black stell pipe. It comes in different thickness. .. most common are sch 20 or 40.

I don't know for a fact what kind of steel is used, but I'd bet you money it's not water pipe quality.

Auto chassis typically use two different grades of steel, depending on the location of the component. Highly stressed sections use "high strength steel" and lesser parts don't. I suspect the low grade steel is something like SAE 1018, and the high strength is 4130. This is just a guess though. 4130 is commonly denoted chrome moly steel, and not overly expensive. Considering all the labor involved with switching out frame sections I'd splurge and spend the extra $10 and get the better steel material.