1018 steel polepieces

[marcfrom]

1215 cold roll steel is the correct vintage choice for slugs. It is also the logical steel choice for use with an automatic screw machine which is how slugs were made. Screws were made with a cold header screw machine and alloys as low as 1006 were used and several others with higher carbon contents. I tested several vintage screws and and got several different alloys, none of which were 1022, 12L14 or 1215 for screws.

I'm pretty sure Gibson bought screws made to order not off the shelf. Although they probably did not specify the steel given the variation in vintage screw lab results.

Interesting!

I use 1215 slugs.
You said you found 1006 but did you find 1010, 1018 ?