Welding cold/hot rolled steel

[Syncmanatl]

Made an S shape tool rest for a wood lathe, in a mini paint can forge from some 5/8 rod. Not enough material for the post. I am trying to buy a small 5/8 piece from metal center, but not sure which to buy, [hot/cold rolled] or if it even makes a difference welding to some unknown steel.

[ThomasPowers]

What did the spark test say your carbon content was?   Hot rolled or cold rolled does not address the ALLOY  which is what can mess things up in welding.

[John McPherson]

Cold rolled just means cleaner starting material, normally only used for projects where the finish matters. 

If you are going to forge it, you ruin the cold rolled finish as soon as you stick it in the forge and get it hot.

If you are going to arc weld hot rolled, cleaning the mill scale from the 1/2" or so that you are actually going to weld should only take a few minutes at most.

[Syncmanatl]

Apologies. A bit more info. I bought a 5/8 rod from metal supermarket, and made the wood lathe T tool rest. Made the S piece a lot later, and couldn't remember if it was hot or cold rolled that I had bought.  Now they asking me what type, and just need to know if it makes a difference when it comes to welding? I have access to a cheapie wire welder in a shared maker space. The tools are for the lathe at the space.  BTW I spent more time grinding than welding, but got it done eventually.

 

https://wiki.themakerstation.com/Main_Page

[Goods]

For general purposes hot rolled will work just fine and is welded everyday in fab shops.

David

[Irondragon Forge ClayWorks]

Welcome aboard... I always recommend reading this to get the best out of the forum.  READ THIS FIRST   It is full of tips like editing your profile to show your location and may help in staying off the moderators radar.

[arftist]

Cold rolled, which is actually cold finished can be welded to hot rolled with no problem whatsoever. 

Cold rolled is more resistant to bending but more importantly it is sized very accurately. 

If it is sold as 5/8 it will measure exactly .625 which is pronounced 625 thousandths.

It is because of this accuracy that the cold rolled piece will work better (fit better.)

It isn't just about finish, it is about fit and finish.

[Frazer]

I know it's an older thread, but since it's popped up I'll add to Arftist's statement. As a result, cold rolled costs more. If you would like to transform your CR steel into HR quick, fast, in a hurry, toss it in the forge