TP-B1237: #112 Duplex Gear

* This the half nut for the main leadscrew on the TP-1237 lathe *

* This shaft #254 is for the gearbox of the TP-G1237 bench lathe *

* This part #336 is for the saddle of the TP-G1224 bench lathe * has a gear on the end of this shaft to engage with the rack to move the saddle along *