A builder’s crowbar and a carpenter’s pick are tamei. Tent pegs and surveyors’ pegs are tamei. A chain of surveyors is tamei. [But a chain] used for wood is tahor. A chain of a large bucket [is tamei up to] four handbreadths, and [a chain] of a small one [is tamei up to] ten [handbreadths.] A stand of blacksmiths is tamei. A saw whose teeth one set into the [door] space is tamei. [But if] one turned it upside down, it is tahor. All covers are tahor except that of a boiler.