Solid stock to heavy wall pipe?

[blunosr]

Hi, I'm making a fencing attachment and for the spike I'm using very heavy wall (7/16) pipe, and a pin that I got at the junkyard, which I think probably came out of a bulldozer. The pipe is 2 and 3/8" OD so you can have some sense of scale. The pin (now the point) is extremely hard, I had to use a titanium cutter. The pipe is also very hard, but I was able to drill and tap two holes in it (just barely). This is all from oil and gas industry stuff, so good materials.

I plan to put two grade 8 bolts in to hold the point in place in the event that the weld breaks.

So, my question is do I need to pre-heat this before welding, and if so, how hot? The point is solid steel.

Also, I have 1/8 - 6010, and 5/32 - Shield-Arc Hyp+ 7010 rods. Which would you recommend? Is there a better rod to use?

How many amps?

Thanks for any advice,

Troy

 

[cowski]

use the 1/8 6010 for the first pass then cap it with 7018.no preheat necessary.

 

[Groo]

might it be worth beveling the pipe too?

 

[Raspy]

If that pin is high carbon steel and you are putting some kind of load on it, I'd weld it with 309/316 stainless. That will make sure it's not brittle and it won't crack. No set screw needed. With items like that you can't go wrong with stainless.

 

[KWentling]

You absolutely need to preheat carbon steel. The heat affected zone will be very hard and brittle with no or insufficient preheat. At least 450 F. E7018 would be good.

Kim