I can watch this over and over - Making Chain

[AntarcticPilot]

These video clips have been around for some time now so may not be totally representative of current production. I am informed that most Chinese chain manufacturing equipment today is German, installed recently and maintained by German technicians. I think the reason that Chinese chain was so good in my latest destructive testing exercise is that it is made from a construction steel, of which there is a vast amount in China, as opposed to the minimum specification dead mild steel that is perhaps quite difficult to source.

I find it intriguing that when the weld current is applied it chooses to form an arc at the joint rather than go around the wire and short out the supply!

The plasma in arcs has a very low resistance, so once the arc is struck the long way round through the link will be the high resistance route. This, by the way, is why incandescent light bulbs have a fuse built into them: when they go phut the arc along the path of the vaporised filament can draw very high currents.

And I think I saw that there was a sort of wedge introduced into the joint that was withdrawn as the weld proceeds; presumably as that is withdrawn the arc is struck. That's what I guessed when I wondered the same thing as Vyv! But I have no experience of welding, so I am just guessing.

 

[Bru]

Hah, all that faffing about with little stuff and tichy machines, this is how it used to be done

[video=youtube;k_LA_R4ifYk]http://www.youtube.com/watch?feature=player_detailpage&v=k_LA_R4ifYk[/video]

 

[Leighb]

That is pretty amazing, the skill involved with up to 6 blokes all swinging sledgehammers in a confined space is extraordinary. It is easy to forget how things used to be made not so very long ago. I expect H & S would have some things to say. The heat, noise and fumes must have been appalling.

 

[Bru]

That is pretty amazing, the skill involved with up to 6 blokes all swinging sledgehammers in a confined space is extraordinary. It is easy to forget how things used to be made not so very long ago. I expect H & S would have some things to say. The heat, noise and fumes must have been appalling.

The physical effort involved is astonishing, those guys must've been made of iron themselves to keep that up for a whole shift in those conditions!

 

[peterandjeanette]

In my early days at a heat treatment factory it was my job to harden the chain. Your initial video shows a chain made from carbon steel being induction hardened then tempered.
The early chain was all mild steel therefore we had to induce carbon to case harden the chain. This was done in a bath of molten cyanide at 900 degrees C. It was then lifted from the molten cyanide by a rope hoist, run along a gantry to the water quench tank and dropped in. One hell of a bang as it quenched. Great fun. Scared the hell out of any visitor.
Believe it or not, my factory still uses molten cyanide for case hardening.

 

[LittleShip]

The physical effort involved is astonishing, those guys must've been made of iron themselves to keep that up for a whole shift in those conditions!

I just wonder what their calorie intake for the day would be, using that amount of energy each working day

Tom.

 

[Roberto]

Hah, all that faffing about with little stuff and tichy machines, this is how it used to be done

"...where a gang of men without counterpart in the country..."


you bet

 

[vyv_cox]

The physical effort involved is astonishing, those guys must've been made of iron themselves to keep that up for a whole shift in those conditions!

Around 15 years ago I was working in Oman, where a new swimming pool was being constructed at the company recreation establishment. The old pool was heavily built in concrete, which was being broken up by hand for fear that pneumatic drills and other powered equipment would damage the nearby buildings. I recall returning there for lunch one day, to see a ring of about ten men in suits and hard hats watching one Indian guy with a big sledgehammer banging away at the concrete. He was tiny, about 5 ft tall and only about 8 stone by the look of him but he kept hammering away for almost the whole half hour I was there. Quite awe-inspiring.

 

[Sandro]

The hand forging video is wonderful. Our young people can't imagine how certain jobs were, a few decades, not centuries ago.
From one end to the other one. Similar work in quite different scale. In the London Tower Weapons Museum medieval coats are exhibited made of mild steel cloth, consisting of tens of thousands of very small links (rings), each threaded with two others, each one was welded after threading. What I can't understand is how the link could be kept hot whilst welding, being so small.
Moreover, one link every so many is marked with the logo of the manufacturer, all on a wire of about 1.5 - 2 millimeters.