18th/19th century lathes

A newbie with a couple of queries.
Can someone suggest a source,I'm wondering how feed rods and leadscrews were cut in the early development of metal working lathes 18/19th century.
How does one cut a regular thread on a yard long bar of wrought iron? How did Maundsley cut his tapered master for his screw cutting lathe?

Feed rods would have been cut on a planer.

"English & American Tool Builders" by Joseph Wickham Rowe discusses the development of the feed screw by a number of methods. Starting at page 39 at English and American tool builders

One imagines in reality it would not be unlike generation of a plane surface on one using two other planer surfaces. Each worked against the other in a sort of "round robin" of scraping/grinding/matching. Or for the lead screw working two screws together to make a third - although in the case of the lead screw it might be using one screw to in turn refine the other two.

Joe in NH

Here is an article on hand chasing threads. Google Books

If you use the forum search on this forum and search for Maudslay or Whitowrth there are a number of older threads that looked into early lathes and threading .

Here are some of them

https://www.practicalmachinist.com/...ory/very-old-lathe-114230/?highlight=Maudslay

https://www.practicalmachinist.com/...thread-manufacture-270065/?highlight=Maudslay

https://www.practicalmachinist.com/...ine-tools-close-up-271737/?highlight=Maudslay

https://www.practicalmachinist.com/...reads-17th-century-248731/?highlight=Maudslay

Some of the pictures may no longer be available or links may not work but may give you some ideas.

Regards,

Jim

Most certainly not wrought iron. By the 1760s they were casting steel in England. Things like a presicion screw thread would been next to impossible to make without some decent steel. Was
It Huntsman who invented the process?

MrStretch said:

Most certainly not wrought iron. By the 1760s they were casting steel in England. Things like a presicion screw thread would been next to impossible to make without some decent steel. Was
It Huntsman who invented the process?

Click to expand...

It is definitely possible to make a precision thread in wrought iron and it would be more likely that most lead screws would have been wrought iron at least up until the 1850's. I have seen wrought iron fasteners and parts made into the 1890's and one large part of an engine made of wrought in 1913. I have also threaded wrought iron and I had no problems with it.

MrStretch said:

Most certainly not wrought iron. By the 1760s they were casting steel in England. Things like a precision screw thread would been next to impossible to make without some decent steel. Was
It Huntsman who invented the process?

Click to expand...

The Huntsman process made crucible steel. Many items were marked "cast steel" but this was reference to the process by which it was made, not to casting shapes. That doesn't come along until much later. Prior to the Huntsman process the English imported steel from Germany and India. The Indian steel, called Wootz, was highly regarded and much of the English-made steel was marketed as wootz - the presumption being the the imported stuff was better. Huntsman kept very close control over his process...when the Swedish industrial spy R.R. Amgerstein toured England in the 1750s the Huntsman works was one of the few places that refused him admittance. Angerstein was an official of the Swedish iron mining association. He was in Britain to study the iron industry, presumably with the goal of selling them more Swedish iron. British iron was only suitable for nails and other simple purposes. For anything that required higher grades of material Russian, Swedish and Spanish iron was used.

Huntsman's big advance was to melt the iron with carbon in a sealed crucible using mineral coal as a fuel. The most that could be made in any one melt was about 40 lbs. Until coke was developed, coal was not suitable for smelting iron. Charcoal was used but by the middle of the 18th century most of the forests had been cut down and it was getting very expensive...I think that all of the early, big screws were made of wrought iron. Huntsman's steel was largely used for small, precise items like gun locks and springs.

Many thanks Jim, oh what a merry chase!

Don't know how I missed this gem thanks a million.
Being pig ignorant of lathe development and versatility I was flummoxed by Maudsley's master screw.
The step forward to producing iron feed rods{for want of proper term,the long threaded thingummy that guides the cutter whatsit}for use in a metal turning lathe rather than the system used for wood turning.
Cutting a thread by hand on a metal blank using a fixed guide seemed nightmarish hard.
Apologies for my stumbling style,Im well out of my depth here.

You are asking good questions...and we all had to start somewhere.

Quite a lot of the historical part of this discussion will be new to most of the members of this forum. This may be the largest assemblage of folks with experience in 18th and 19th century machine tools but we are still a small minority in the machinist world. Since there is relatively little published on the subject, a lot of our information comes from experience and reading period literature...it isn't something you can easily "research on the internet."

I've cut a small leadscrew in wrought iron for the compound on an old lathe I have. No name or date-all I know it was 3rd hand in 1890 and had beven on a farm in Shildon. Anyway,the WI cut like a dream. Runs like a dream in a new nut with CI from an old Desoutter dieset!