Is this cast iron or cast steel?

[Turbo]

It's the top ring of the rack & pinion for lifting the table on a Meddings pillar drill. It is cracked through where the black marker is & I want to repair it. The rod of the rack attaches where the hole is & it pushes on the table, the ring is there to stop the rack bowing away from the column.

I'm thinking that cast iron wouldn't have the tensile strength for this item so it must be cast steel? That means I can tig weld it? If its cast iron I'll braze it using oxy propane.

I've a clamp ring on a Qualters & Smith drill & it is broken too.

I'd like to fix this one too, so any advice appreciated.

Of course if anyone has a spare clamp ring for a 70mm dia column drill I'd be very interested in it.

 

[Agroshield]

Small triangular file feels different on cast iron vs. steel. Braze it as that method works for both materials and sidesteps the problem. If you can see the fracture surface, that can give you some clues. Relieve the sharp internal corners with a needle file before reassembly. I am leaning towards it being cast iron as steel does not fail like that.

On the Q&S, make a new one - CNC plasma the blank, holesaw the middle, bore it out, tapping drill, clearance drill, counterbore and thread. Slit with junior hacksaw. Put a piece of gasket material in the slot on reassembly to stop overtightening (which has likely caused the first failure). You could make it a simple D-shape out of plate. Finish the hole first and then cut as close to the outside lines with a grinder, and refine the shape. A deep counterbore would allow you to use the same capscrew.

 

[brightspark]

give it a grind and if the sparks are a dull red its cast iron

 

[Brad93]

Cast iron that will be

 

[gordon stephenson]

Certainly would expect it to be cast iron, As above do a small spark test. We had one break on a much bigger radial arm drill, Around 12" bore and 12"high, Only satisfactory repair was Metalock stitching, Worked a treat is still going strong,

 

[Turbo]

Thanks to all for your replies.
I'll treat it as cast iron & I've started a new thread on brazing it.
https://www.mig-welding.co.uk/forum/threads/how-would-you-braze-this.117133/