Specialty Tooling and Repair-Part Planning

Describe the job the tooling must perform

Start a tooling RFQ with the operation and interfaces. Provide the workpiece model or drawing, machine or assembly interface, expected quantity of uses, access requirements, and any existing tooling that must remain compatible. State whether the supplier is manufacturing a released design or being asked to propose one for customer approval. These are different scopes and should be quoted distinctly.

For a fixture, identify the surfaces or features that establish location. Carr Lane's fixture guidance separates locating the workpiece from clamping it in that location, and discusses supports, chip clearance, and orientation control. A clamp should not be expected to compensate for an undefined locating scheme. [1]

Ask the operator to review the proposed loading sequence. Include practical requirements such as access for fastening, inspection, cleaning, and replacing wear items. A useful review can expose ambiguity before it becomes a machined detail that is expensive to change.

Build around location, support, and access

The familiar 3-2-1 locating arrangement uses three primary supports, two secondary locators, and one tertiary locator for an appropriate workpiece. It is an example of a locating strategy, not a mandatory layout for every shape. Carr Lane also recommends directing clamp forces toward supports and planning for chips around locating surfaces. [1]

Translate that principle into review questions: Which features establish position? Where do the loads enter the workpiece? What keeps an incorrectly oriented part from being loaded? Can chips be removed without dismantling the tool? Can the cutting tool and holder reach the required surfaces throughout the operation?

Consider standard locating and clamping components before specifying every item as custom. Carr Lane describes commercial locators and distinguishes fixed and adjustable arrangements. For the buyer, that suggests a useful maintenance discussion: identify replaceable items, part numbers, and access for replacement. It does not mean a catalog component is automatically suitable for the proposed load or environment. [2]

A worn sample is evidence, not a complete drawing

Reverse engineering can create CAD information from a physical item. Hexagon's description explains this measurement-to-model workflow. A manufacturer's example also illustrates why worn areas and damage may need design interpretation before a replacement model is finalized. Copying the current surface exactly can preserve the wrong condition. [3] [4]

For a repair or replacement part, provide every available source of design intent: original drawings, equipment manuals, mating parts, prior inspection reports, service history, and an explanation of the failure. Mark dimensions that are known requirements separately from dimensions inferred from the sample. Identify whether the goal is like-for-like replacement, restoration to an approved condition, or an authorized redesign.

Do not infer alloy, heat-treatment condition, coating, or critical tolerances from appearance alone. Ask what verification or engineering decisions are necessary to establish the released replacement definition. If a sample is the only information available, make the investigation and approval stages explicit in the scope. Machining should follow an approved definition rather than conceal unresolved assumptions.

Separate urgent work from unresolved requirements

A production stoppage makes fast communication valuable, but urgency does not identify the correct fit or material. Send an initial package with the operating context, photos, available documents, part quantity, required delivery date, and a named technical decision-maker. Ask the supplier to separate what can be quoted immediately from what requires a drawing clarification, measurement, or outside service.

For a small batch, discuss whether the quoted scope includes a first-piece review, a trial fit, retained tooling, spare wear components, and documentation for a repeat order. Decide who supplies mating hardware and who performs functional acceptance. A successful bench measurement and a successful assembly trial answer different questions; state which evidence the order requires.

If the proposed repair changes a released requirement, document approval from the responsible design authority. Do not let an expedient manufacturing suggestion silently become the new design baseline. Preserve the final approved definition so the next replacement does not begin with the same uncertainty.

Define acceptance and handover together

A tooling delivery can include more than the metal item. Agree on the drawing revision, inspection results, purchased-component list, assembly instructions where needed, and the identification used for future reorders. For a fixture, specify the demonstration or trial required for acceptance. For a replacement part, identify the interfaces and characteristics the receiving team must verify.

Where measurement results support acceptance, consider whether the method is fit for the requirement. NIST explains that traceability alone does not establish fitness for purpose; the uncertainty and measurement process matter. The same principle applies whether the work is a large production lot or a single replacement item. [5]

Keep revisions under control after the trial. If a locating pin, clearance, or interface is changed during an approved fit check, update the documentation to match the delivered item. Label proposed changes distinctly until approved. This makes a future repeat order possible without reverse engineering the last repair.

Match the work to the available shop processes

ATM's shop-supplied records list CNC and manual machining, grinding, boring, broaching, honing, and inspection equipment. Its equipment page also identifies tooling, fixturing, and subcontract work as applications for the fleet. These listings support an initial discussion; a specific part still needs review for setup, material, process, and acceptance requirements. [6]

Review ATM's machining processes alongside the equipment register. If the project starts with a drawing, use the tolerance planning guide. If it starts with inspection questions, read how to scope a CMM report. The Machining Knowledge hub connects the remaining topics. A complete RFQ lets the shop respond with a concrete manufacturing plan and clearly identified open questions.