prec - prog
- precession
- precession angle
- prechamber
- precious metal
- precipitant
- precipitating agent
- precipitation hardening
- precipitation tank
- precision
- precision alloy
- precision balance
- precision casting
- precision forging
- precision grinding
- precision instrument
- precision lathe
- precision level
- precision machine tool
- precision measurement
- precision parts
- precision square
- precision straight edge
- precision tool
- precombustion chamber
- precombustion chamber engine
- precompression
- precooler
- prediction
- preevacuation pump
- prefilter
- preheater
- preheating
- preheating furnace
- preliminary treatment
- preload
- preloaded bearing
- premachining
- premature ignition
- preselection of tools
- preselective control
