Posted by Drew Hause on May 21, 2019, 4:16 pm, in reply to "Re: hinge pins"
c. 1890 Hunter Arms Fulton “Transition” L.C. Smith Hammerless and 1909 L.C. Smith No. 00 were both were non-standard but similar to Bessemer Resulphurized (very high Sulphur) AISI 1109 Low (.09 & .12%) Carbon Steel.
Plans & Specifications of the L.C. Smith Shotgun by William S. Brophy contains an undated but likely post-1913 Materials Specification chart indicating “AISI 1020 Carbon Steel” for the frame.