I am wondering what the maximum sized (cross section) billet (1085/95 & 15N20 strips) is that one should undertake for drawing out by hand using just anvil (200 lb) and hammer (3 lb)? My intent is to make a twisted core with layered laminated edges. Also, to be traditional, would migration era smiths have worked with similarly small strips and then welded the strips together without a team of strikers?

In my case, the desire to do it this way is mostly driven by lack of appropriate space and budget for a modern air powered hammer. I sought to enroll in a local class for fabrication of a "tire hammer" (uses a spare tire hub as a cam to drive 50 to 75 lb hammers), but there was not enough local enrollment for the class to be held.

As someone who started making pattern weld with a coal forge and hand hammering, I would say that 1 - 1.5 inches wide, 5 inches long, and around 1.5 - 2 inches tall should ge a good starting point.

I don't know if it is historically to combine two billets to increase layer count and size, but I find it much better to work two billets and then weld them together if I need a larger billet. If you are working a huge billet you are going to end up fighting with it and might end up scraping more material and time then if you take your time, work small, and then add on to get the size/layers that you need.

Thanks for the input Michael.
I would like to end up with twisted core strips long enough for a gladius type sword. I realize that these were often stacked with several different thin pieces making up the overall cross section. I don't really mind the center strips losing some carbon over time and working, as I figure that is more true to original than perfect modern pattern welded.

Depending on how many layers you are going for you should be able to get enough material for 2 twisted rods out of one billet that started out the size that I mentioned before, or more, depends on you and your set-up really.

Depending on your skill level, two billets should get you a Gladius type sword.