To hand out tools to their employees. If you needed a tool you went to the tool room/crib and the attendant would give you the tool you needed any you would give the attendant a "tool check" that had a number unique to you stamped on it.
Vintage Baltimore & Ohio Railroad Co. Brass Tool Check Chit Shipping Tag
Antique Brass Tool Check Tag / Token / Fob Western Maryland RR Railway
British Columbia Railway Company B.C.R.C. 1929 Brass Tool Check Tag, BEAUTIFUL!
S.R.M. Brass Tool Check / Works Token No 12 (R4) – Railway/Industrial c.1930s–50
Vintage Brass Time Check Reading Car Shops Reading Co. Reading Railroad Lines
Vintage P&R Philadelphia & Reading Railroad Tool Check Brass Tag