1018,1020 vs 1026 help

I'm working on a project that I'm using 2" ID X 2.5" OD Given 1/4" walls 36" long round tube. I'm looking to do some machining and a little welding on the piece. I have been told by one source that 1020 would be much to brittle and hard to machine. In contrast I have been told that it is relatively easy to work with and even if I had 1018,1020 and 1026 side by side I would not notice the difference. and that it is a wonderful cold roll mild steel to work with. I have been told different hardnesses by 2 places Going from B65-B89 on the 1020...so you could imagine my feelings of helplessness trying to figure out what to use. (this is my learning curve).

This is going to be for a rifle project I'm working on (50BMG). This Q has been posted on the gunsmithing forum but things got off topic and nobody has answered my Q. Somebody please help me as I'm tired of chasing my tail in circles.

My experience with all 3 is that they are very easy to work with. Relatively soft and easy to cut, the very definition of mild steel. I find them hard to get a nice finish on unless I cut them with carbide at high sfm. Welding is a breeze, TIG with ER70s-2 filler or MIG or stick with just about anything. 1026 is a little easier to get a finish on than 1020 or 1018, I generally find tubing made in 1026.

You won't know the difference - so make sure you mark them if getting more than one. All three are considered mild steel and will be pretty close to dead soft and not capable of through hardening (although they could be case hardened or nitrided).

First, 1018/1026 are all carbon steel with different chemical properties. Mechanical properties such as hardness, tensile, and yield strength can be brought to the desired range through the heat treating process. For instance there is a hardness range from 70 to 97 Rockwell ‘’B’’ Scale, Yield Strength 35 to 80 ksi, and Tensile 60 to 115 ksi. that can be achieved. All of which are easy to machine. I would suggest you ask which type would be recommended for your application considering you will be welding on this material and I assume this is going to be used as a barrel for a rifle.Stress relieving after welding would be something to think about. I know this is not an ''answer'' but it really depends on the application.

Any of the three will be fine. All of those can be welded and re-machined without any adverse effects. They will stay soft and machinable after you weld them. If it is tubing, it is most likely 1026, most hot formed tubing is. Cold rolled usually is 1018. There shouldn't be any need to stress relieve those steels after welding unless you have a very intricate part or have a LOT of stock to remove after welding. Even then, just rough everything out leaving finishing stock and it shouldn't move with the light finish cuts. The person who told you 1020 will be too brittle and hard to machine must have been hitting the crack pipe that day...or just doesn't know WTH he's talking about.

No this is not to be used for a barrel....its going to be the receiver for a tube gun in 50BMG though its not taking any of the bolt thrust pressures. the bolt and barrel extension will take care of that.

k Thanks, I think he was going on it might be to brittle because of the info we pulled off of a website that said it had a hardness of 89. The tube will be used for a receiver tube for my 50BMG thanks for the help guys you have been most helpful.

Just to define further, B89 is less than C13 on the Rockwell charts. As a comparison, 4140 "prehard", still very machininable and far from "brittle" is about C30 - off the chart in the B scale.

John