parting line: meaning, definition, pronunciation and examples
C1/C2 – Technical / SpecialisedFormal, Technical (Manufacturing, Engineering, Foundry work), Occasionally used figuratively in formal contexts.
Quick answer
What does “parting line” mean?
The visible line on the surface of a moulded or cast object where two halves of the mould meet.
Audio
Pronunciation
Definition
Meaning and Definition
The visible line on the surface of a moulded or cast object where two halves of the mould meet; a seam or mark left by this junction.
1. (Manufacturing/Engineering) The boundary line on a manufactured part where mould sections separate. 2. (Figurative/General) A line of division, separation, or demarcation between two things or states.
Dialectal Variation
British vs American Usage
Differences
No significant difference in core meaning. 'Parting line' is the standard term in both regions for moulding and casting. US technical manuals may occasionally use 'parting line' interchangeably with 'flash line' where excess material escapes the mould.
Connotations
Neutral and purely descriptive in technical contexts. In figurative use, it may carry a slightly negative connotation of an artificial or undesirable boundary.
Frequency
Common term within specific industries (toolmaking, plastic injection moulding, die-casting) in both regions. Very low frequency in everyday language.
Grammar
How to Use “parting line” in a Sentence
The [NOUN] has a visible parting line.The [TOOL/MOULD] was designed to [VERB: place/hide/minimise] the parting line.[VERB: Polish/Grind] the parting line to improve the finish.Vocabulary
Collocations
Examples
Examples of “parting line” in a Sentence
noun
British English
- The quality inspector rejected the batch due to a prominent parting line on the bezel.
- The engineer explained how the parting line affects the draft angle.
American English
- The design needs to relocate the parting line to reduce post-machining.
- Parting line flash is a common defect in high-pressure die casting.
Usage
Meaning in Context
Business
Used in manufacturing procurement or quality control discussions: 'The supplier must ensure the parting line is not visible on the final consumer product.'
Academic
Used in engineering, materials science, or design papers: 'The study analysed the effect of different gate locations relative to the parting line on weld line formation.'
Everyday
Extremely rare. Might be used figuratively by a careful speaker: 'The new road acted as a parting line between the old and new neighbourhoods.'
Technical
Core usage. Refers to the planned separation surface of a mould. Critical for tool design, part ejection, and finishing processes.
Vocabulary
Synonyms of “parting line”
Strong
Neutral
Weak
Vocabulary
Antonyms of “parting line”
Watch out
Common Mistakes When Using “parting line”
- Using 'parting line' to describe a hair parting (use 'part' or 'hair parting').
- Confusing 'parting line' with 'flash' (flash is the excess material *on* the parting line).
- Using it as a general synonym for 'border' in non-technical writing.
FAQ
Frequently Asked Questions
In manufacturing, they are closely related but distinct. The parting line is the *planned* junction of the mould halves. A 'seam' often refers to the *resulting line or ridge* on the finished part, which is the physical manifestation of the parting line.
Yes, but it's uncommon and usually figurative, leveraging its technical meaning to describe a clear line of division (e.g., 'a parting line between belief and skepticism'). In everyday speech, 'dividing line' or 'boundary' are more natural.
It's a thin, unwanted web of material that escapes from the mould cavity along the parting line due to mould wear or excessive injection pressure. It must be removed in a secondary operation called 'deflashing'.
The pronunciation is straightforward: PAR-ting (with a clear 't') + LINE. The stress is on the first syllable of 'parting'. In connected speech, the 'g' in 'parting' often elides into the 'l' of 'line'.
The visible line on the surface of a moulded or cast object where two halves of the mould meet.
Parting line is usually formal, technical (manufacturing, engineering, foundry work), occasionally used figuratively in formal contexts. in register.
Phrases
Idioms & Phrases
- “(Figurative) The policy created a sharp parting line between the two communities.”
- “(Technical) The flash is trimmed from the parting line.”
Learning
Memory Aids
Mnemonic
Think of a PARTing of ways: the two mould halves PART company along the PARTING LINE, leaving their mark behind.
Conceptual Metaphor
SEPARATION IS A VISIBLE LINE. A PROCESS OF DIVISION LEAVES A TRACE.
Practice
Quiz
What is the primary concern with a poorly designed parting line in manufacturing?