Can I request a tolerance review or optimization during the quoting process?

Can I Request a Tolerance Review or Optimization During the Quoting Process?

Direct Answer: Request the Review Before the Quote Is Fixed

Yes, you can request a tolerance review or optimization during the quoting process, and the request should be made before price, lead time, and inspection scope are fixed. For an RFQ sent to Neway, the useful question is not simply whether a tolerance is tight. The useful question is which dimensions control fit, sealing, motion, datum transfer, safety, or inspection evidence. Tolerance optimization is not permission to weaken the design or remove drawing intent. The buyer must approve any relaxation, GD&T change, material assumption, surface finish change, or inspection method before the quote becomes a production commitment. For medical-grade titanium or other difficult materials, early review can prevent avoidable tight features from controlling machining, measurement, and lead time. The RFQ should include the latest 2D drawing, 3D model, material grade, heat treatment or stock condition, annual quantity, mating part information, and the dimensions that cannot move.

How the Tolerance Optimization Process Works

Once you submit a 2D/3D drawing and specifications, quoting engineers should evaluate dimensional tolerances alongside material type, datum scheme, surface finish requirements, production quantity, and inspection evidence. If tolerances tighter than ±0.01 mm appear on non-critical features such as cosmetic surfaces, clearance pockets, label areas, or non-mating geometries, the supplier should flag them for discussion rather than silently quoting an expensive route. A useful review groups dimensions into critical, controlled, and general features. Critical features protect fit, sealing, motion, load path, or compliance. Controlled features need repeatability but may not need ultra-tight values. General features can often follow title-block or ISO 2768-style general tolerances when the drawing invokes them correctly. The review should also separate size tolerance from position, flatness, perpendicularity, concentricity, runout, and surface roughness because each item may require a different control method. A bore held to a size limit, for example, is not the same quotation problem as a bore held to position from two datums after anodizing or heat treatment. Ask the supplier to mark the affected features and state what would change if the tolerance is adjusted.

Benefits of Tolerance Optimization

Reviewing tolerances during quoting can improve cost, lead time, manufacturability, and inspection planning, but the benefit comes from feature-level decisions rather than broad tolerance cutting. On an aerospace aluminum component, for example, a bearing bore, dowel hole, or sealing face may stay tight while a pocket wall, logo surface, or external contour uses a looser tolerance. This prevents unnecessary finishing passes and CMM checks on features that do not affect assembly. A practical tolerance review should answer four checks. Does the feature touch another part, carry load, seal fluid, guide motion, or locate a datum? Does the material or wall thickness move after roughing, unclamping, heat treatment, or coating? Can the feature be measured with the requested datum scheme, or does the drawing need a clearer inspection reference? Will a looser value actually reduce setup count, tool choice, finishing pass, inspection method, report format, or approval loop? If nothing changes, the tolerance review may not affect the quote. If one or more checks changes the route, the buyer can approve a controlled optimization instead of paying for precision where the assembly does not use it.

Relevant Manufacturing Services You May Need

● Precision Machining Services are relevant when the drawing contains datum-controlled bores, positional tolerances, fine surface finish requirements, or critical dimensions that need measured evidence. Use this route when the supplier must plan finishing passes, stable workholding, calibrated inspection, and an agreed report format before quotation.

● CNC Machining Prototyping helps test whether the proposed tolerance plan supports fit and function before the drawing is released for low-volume or production batches. A prototype review can show whether thin walls move after unclamping, whether a mating bore needs the tight value, or whether the tolerance can move to a more measurable feature.

● Multi-Axis CNC Machining may reduce setup changes when several critical features need to be held from related datums or reached from compound tool angles. The buyer should confirm whether multi-axis access improves datum consistency or only makes the toolpath convenient, because those are different quotation benefits.

● Superalloy CNC Machining should be discussed early when heat, tool wear, slow cutting, or work hardening can make unnecessary tight tolerances expensive. The review should identify which features truly need tight limits after roughing stress, tool wear, and inspection access are considered.

● One Stop Service is useful when tolerance, finishing, inspection, packaging, and approval timing must be coordinated in the same RFQ. Before approving the quote, ask for a written list of accepted tolerance changes, unchanged critical dimensions, inspection method, and any assumptions that affect price or delivery. Keep that list with the purchase order so quotation optimization does not become an undocumented drawing change later.