Intake Manifold Thread + Chip Control RFQ Checklist: Sensor Bosses, Ports, Deburr, Cleanliness, and Gauges

# Intake Manifold Thread + Chip Control RFQ Checklist: Sensor Bosses, Ports, Deburr, Cleanliness, and Gauges

Intake manifold programs can fail even when the casting “looks fine” because thread and cleanliness details were never defined in the RFQ. One supplier quotes basic machining, another assumes extra deburr and wash, and neither assumption is visible until assembly has leaks, stripped threads, or contamination problems.

This checklist helps you write a quoteable intake manifold RFQ that makes thread requirements and chip control explicit.

Useful Bohua routes:

• •Intake manifold quote route
• •Truck intake manifold product example
• •Runner/core + cleanliness checklist
• •Flange flatness + port machining checklist
• •Structured RFQ upload

1) List every threaded interface (and what it seals)

In the RFQ, list thread groups such as:

• •sensor bosses (MAP, temperature, pressure, knock, etc.)
• •vacuum ports and barbed fittings
• •coolant-related or EGR-related ports (if present on your design)
• •mounting holes that are part of assembly sealing

For each, state whether it is:

• •a sealed thread interface (sealing compound, gasket, O-ring, or tapered thread)
• •a non-sealing fastener thread (torque only)

2) Thread specification must be complete

Do not stop at “M__”. Specify:

• •thread standard and designation (example: M__ x __, or BSP/NPT if applicable)
• •class / tolerance (if applicable for your standard)
• •depth / minimum full thread engagement
• •any coating or surface treatment that affects threads
• •whether the thread is formed, cut, rolled, or insert-based (if relevant)

If you are unsure, ask suppliers to confirm the standard + class from the drawing and list it back in the quote assumptions.

3) Define inspection method and gage evidence

Ask suppliers to state how they verify threads:

• •plug gage / ring gage type and class
• •go/no-go rule
• •sampling plan for threads (per-part vs per-lot)
• •how damaged threads are dispositioned (scrap vs rework)

If threads are a launch risk, request a first-article record including:

• •gage result summary by thread feature group
• •photos of representative thread features (optional, when useful)

4) Deburr + edge-break expectation (avoid silent variation)

Thread and port failures are often burr failures.

In the RFQ, specify:

• •deburr requirement (edge break / “no sharp edges”)
• •whether port edges are deburred before cleaning
• •whether internal burrs are permitted (usually no)

If you have a known limit (example: max burr height), include it. If not, require “no loose burrs or chips after final cleaning” and ask for supplier proposed deburr method.

5) Chip control and internal cleanliness (what “clean” means)

For intake manifolds, internal chips can cause downstream failures.

In the RFQ, define:

• •whether internal passages must be cleaned after machining (yes/no)
• •whether a wash process is required (and whether drying is required)
• •how parts are protected after cleaning (caps/plugs, sealed bags, separators)
• •whether you require a cleanliness check (visual, swab test, or buyer spec)

If you do not have a formal cleanliness spec, require a supplier proposal and document it as part of the quote assumptions.

6) Packaging rules matter for “clean parts”

If you need clean parts, add packaging requirements:

• •caps/plugs on ports
• •separators so faces and bosses are not damaged in transit
• •corrosion protection (if required)
• •labeling with lot and revision traceability

Copy-paste RFQ starter (threads + chip control)

> Intake manifold thread + cleanliness RFQ (copy-paste)

> Files: 2D PDF rev __ ; STEP __ ; machining scope note __

> Thread features: list each interface group + designation + sealing method __

> Thread acceptance: class/tolerance __ ; min depth __ ; gage method __ ; sampling __

> Deburr: edge break requirement __ ; internal burrs allowed yes/no __

> Cleanliness: wash required yes/no __ ; drying required yes/no __ ; chip-free internal passages yes/no __ ; caps/plugs required yes/no __

> Packaging: caps/plugs __ ; separators __ ; labeling/traceability __

> Inspection records requested: layout __ ; CMM __ ; thread gage summary __ ; cleanliness evidence (if any) __

> Quantity + schedule: sample __ ; annual volume __ ; target timing __ ; destination __

Submit a structured intake manifold RFQ

• •Open intake manifold quote route
• •Upload via Request Quote