This a taper plug of the type used for railway boiler fusible plug holes. Almost new this taper plug is marked on the end as follows: 1 5/16", 1 in 12 taper, 12TPI, also 26 (or 28) RW although I don't know what this stands for
Replacement Tap for Cat. No. 627-20, 2-Pack, High-Quality Tap Set.
M&STL RR MINNEAPOLIS & ST. LOUIS RAILROAD STEAMFITTER BOILERMAKERS PIPE WRENCH
6 assorted Boilermakers Langley F201
1936 LMS Royal Scot Taper Boiler Locomotive Railway Technical Drawing Ref T
Taper Fit Brass Burner and Fount Pot Tank for Railroad Lanterns
Alan Gibson - 4mm Spring Buffers NE Taper - 4911
