Tip size is the primary specification — a number 0 tip cuts thin plate, a number 4 cuts thick plate. Using a tip too small for the thickness produces a slow, ragged cut with heavy dross; too large overheats the plate and widens the kerf. Cutting capacity is set by tip size and oxygen supply, not by the torch body.
Tips are fuel-specific. Acetylene tips have a different orifice design from propane and propylene tips because the flame characteristics differ. Using an acetylene tip on propane gives a poor flame and a rough cut.
Two-piece tips have a separate preheat section and cutting oxygen section, which allows the preheat to be replaced independently. One-piece tips are cheaper but must be replaced as a whole. Tip condition matters — a nicked or burnt tip orifice will produce a wandering cut and must be dressed or replaced.
