Checklist · Threads & fittings
Custom Threaded Fittings: RFQ Checklist for OEM Buyers
A comparable quotation starts with the same drawing revision, material specification, quantity, critical acceptance features and delivery scope for every supplier. Identify the thread family explicitly. BSP, NPT and metric connections should never be inferred from an approximate measured diameter.

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The custom threaded fittings decision
Identify the thread family explicitly. BSP, NPT and metric connections should never be inferred from an approximate measured diameter.
This guidance concerns adapters, connectors and drawing-defined hydraulic or pneumatic interfaces. For this subject, turned and threaded fittings are made to a reviewed specification; connection pressure ratings and sealing suitability require buyer-defined validation. The quotation and approval plan should reflect the actual component rather than a general claim about precision manufacturing.
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Define the order before requesting a price
Identify the part number, PDF revision and matching STEP or IGES model. If the model and drawing disagree, resolve the difference before suppliers program the part. Include sample quantity, batch quantity and annual demand separately; each can imply a different setup and stock purchasing decision.
State the material grade and condition, inspection documents, permitted substitutions, final surface condition and destination. Distinguish an engineering target date from an agreed shipment date. A request for a price without these inputs often produces offers with different exclusions rather than genuinely different value.
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Turn assumptions into written quote questions
Ask which features need clarification, which processes are included, and what requires separate confirmation. Have each supplier identify tooling, fixture, material, inspection and packing assumptions. Send the same clarification to every bidder so the comparison remains fair.
List mandatory requirements separately from preferences. If a requirement is provisional, mark it as such and ask for the cost or schedule implication. Keep an approved version of the request with the final quotation so later drawing changes do not silently become part of the original price.

Illustrative machining and inspection imagery. - 03 / 05
Decision record for the purchasing file
Subject: Custom Threaded Fittings. Decision: A comparable quotation starts with the same drawing revision, material specification, quantity, critical acceptance features and delivery scope for every supplier. Part-specific question: Identify the thread family explicitly. BSP, NPT and metric connections should never be inferred from an approximate measured diameter. Write the supplier's response beside that question and have the authorised engineer approve any change affecting the mating interface. Keep unresolved items visible rather than treating a received quotation as evidence that all technical requirements have been accepted.
Record the material decision using this criterion: alloy, corrosion environment and any restricted-substance requirement must be stated. Record the feature review against thread family, taper or parallel form, seating faces, cross-holes and the remaining wall section. Finally, record the agreed verification method for thread and sealing features by confirmed methods, with bore and wall-related checks tied to the drawing. These three entries connect the commercial offer to the physical component the buyer intends to accept. If any answer changes after the quote, confirm the effect on price, inspection and delivery before releasing the purchase order.
Use a simple outcome for each entry: accepted as specified, clarification required or engineer-approved alternative. Name the drawing revision and approval reference in the purchasing record. Do not mark a provisional suggestion as accepted until the responsible person has reviewed it. This leaves a clear basis for comparing the first delivered sample with the offer and for deciding what must be repeated on the next batch.
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Part-specific review before release
Material review: alloy, corrosion environment and any restricted-substance requirement must be stated. State the agreed designation and required evidence in the purchase specification. Where service performance depends on the material, the design authority must confirm suitability rather than delegating that decision to a generic machining quotation.
Geometry review: focus on thread family, taper or parallel form, seating faces, cross-holes and the remaining wall section. Inspection should address thread and sealing features by confirmed methods, with bore and wall-related checks tied to the drawing. Resolve any feature outside the confirmed measurement scope before ordering, and use the same drawing interpretation for the sample, production report and receiving checks.
Delivery protection: thread protection and clean internal bores with no loose packing contamination. Identify the part and revision on the delivered batch. Damage, a material mix-up or an unclear report can prevent an otherwise dimensionally acceptable part from entering the assembly.

Illustrative machining and inspection imagery. - 05 / 05
Send a drawing for a scoped quotation
For a review of custom threaded fittings, include thread standard and size, mating connector, sealing mechanism, fluid and required component checks. Upload a dimensioned PDF with its revision and a matching STEP or IGES model when available. Add sample and batch quantities, required documents and the delivery destination so the offer can separate technical scope from logistics.
Precision Machining India holds ISO 9001:2015 and uses LMW, Jyoti and Ace Micromatics turning centres, a 3-axis Ace Micromatics FANUC VMC and Mitutoyo inspection instruments. This does not imply AS9100, ISO 13485 or 5-axis capability. Any additional process or specialised test must be reviewed and confirmed separately. Request an NDA before sharing confidential drawings when needed, then use the quotation form to begin the part-specific discussion.
Frequently asked questions
Get a quote in 24hWhat should an RFQ for custom threaded fittings include?
A comparable quotation starts with the same drawing revision, material specification, quantity, critical acceptance features and delivery scope for every supplier. Identify the thread family explicitly. BSP, NPT and metric connections should never be inferred from an approximate measured diameter.
What information is needed to review my custom threaded fittings part?
Provide thread standard and size, mating connector, sealing mechanism, fluid and required component checks, the controlled PDF drawing, matching model, material designation, quantities and delivery destination. Capability and pricing are confirmed against the actual part.
Does machining approval establish final application suitability?
No. Drawing conformity and machining scope must be distinguished from buyer-defined assembly, service and regulatory approval. Confirm alloy, corrosion environment and any restricted-substance requirement must be stated and any required testing before release.
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Everything below is machined in the same Pune plant to the same ISO 9001:2015 system. Follow whichever is closest to the part you are sourcing.
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Upload STEP, IGES or PDF files. NDA available on request. Quoting: Custom Threaded Fittings: RFQ Checklist for OEM Buyers.