Alarm or big chain

[Blackal]

We used to take lengths of steam pipe, cut V's into them for teeth and get the welders to stellite tip the ends for cutting big holes through brick walls for armoured cables. This was normally before any power had arrived as we were laying it in. (1970s)

They worked very well and normally it was the bit you hit that mushroomed and failed first.

Yeah - it's common for Trawl doors, excavator buckets etc to have a Hardox coating welded onto it, but those items are made from structural steel, which isn't affected so much by the heat input from the weld (some procedures will specify the heat input and the cooling rate)

"Steam" pipe will just be a middle of the road mild steel, of which the properties can't be altered (better or worse) by very much - with the input of heat.

But - chain steel will suffer to a greater or lesser extent by the application of such heat.

Just a thought - I'd be interested to see an impact test of Digger's chain.

Al