# CNC Machined Jigs & Fixtures

> A useful jig or fixture constrains the workpiece from its functional datums without over-constraining it, provides tool and gauge access, and makes wear items replaceable. FabVector can machine baseplates, nests, locators and clamp components, but the RFQ must define the process step and the repeatability the fixture must support.

- HTML page: https://fabvector.com/custom-cnc-parts/cnc-machined-jigs-fixtures (Portuguese: https://fabvector.com/pt/custom-cnc-parts/cnc-machined-jigs-fixtures)
- Quote: https://fabvector.com/quote

## Typical applications

- Machining and drilling fixtures
- CMM and inspection nests
- Assembly and bonding fixtures
- End-of-line gauges and test stands

## Recommended manufacturing route

1. Translate the part datum reference frame into locators, supports and clamps.
2. Separate stable base structure from replaceable wear and changeover components.
3. Machine locating features in a common setup and add hardened inserts where required.
4. Verify fixture coordinates with a master part, gauge or CMM routine defined by the RFQ.

## Drawing and RFQ controls

| Control | Guidance |
|---|---|
| Datum strategy | Use the part drawing datum scheme and avoid clamping across uncontrolled casting or molded surfaces. |
| Access | Leave clearance for cutters, probes, fasteners, chip removal and operator hands. |
| Wear items | Make pins, bushings and contact pads replaceable without re-machining the base. |
| Repeatability proof | Define how many load/unload cycles and which characteristics will be measured. |

## Recommended materials

- [aluminum-mic-6](https://fabvector.com/md/materials/aluminum-mic-6): Stable machined baseplates and inspection nests.
- [aluminum-6061](https://fabvector.com/md/materials/aluminum-6061): Lightweight general fixture structures and change parts.
- [alloy-steel-4140](https://fabvector.com/md/materials/alloy-steel-4140): Loaded or wear-resistant locators and clamp components.
- [pom-delrin](https://fabvector.com/md/materials/pom-delrin): Non-marring nests and replaceable contact pads.

## Manufacturing processes

- [cnc-milling](https://fabvector.com/md/services/cnc-milling)
- [cnc-turning](https://fabvector.com/md/services/cnc-turning)
- [surface-grinding](https://fabvector.com/md/services/surface-grinding)
- [prototype-machining](https://fabvector.com/md/services/prototype-machining)

## Compatible finishes

- [hardcoat-anodizing-type-iii](https://fabvector.com/md/finishes/hardcoat-anodizing-type-iii)
- [black-oxide](https://fabvector.com/md/finishes/black-oxide)
- [electroless-nickel-plating](https://fabvector.com/md/finishes/electroless-nickel-plating)

## Inspection scope to define before production

- CMM report for locator positions and base datums
- Repeatability study with an agreed master or sample part
- Fit and function check of pins, bushings, clamps and change parts

## Buyer questions, answered

### What information is needed to quote a custom fixture?

Provide the part model and drawing, the operation performed in the fixture, machine or inspection envelope, datum scheme, clamp preference, loading method, target repeatability and expected production quantity.

### Can fixture design be included?

Engineering support can be reviewed as part of the RFQ, but scope must distinguish build-to-print machining from fixture design, validation and process responsibility.

### How is fixture repeatability validated?

Define a load/unload study using a master or representative part and measure the characteristics the fixture is intended to control. The number of cycles and acceptance limit belong in the RFQ.

### Can hardened drill bushings and locator pins be installed?

Yes when the component standard, fit, orientation and replacement method are specified. Catalog hardware can reduce future maintenance time compared with custom wear components.

## Related engineering guides

- [Semiconductor fixture machining guide](https://fabvector.com/blog/cnc-machining-for-semiconductor-fixtures)
- [Inspection and quality documentation](https://fabvector.com/quality)