Brushed Finish for Drawing-Based CNC Parts and Tooling

Straight-Line Directional Brushing

Straight-line brushing runs parallel abrasive lines across a planar, accessible face. It suits plates, housings, and visible mold accessories; specify direction from a datum edge, grain continuity, and boundary limits.

Cross-Hairline Texture

Cross-hairline texture uses intersecting fine lines for a subdued, less directional appearance. It suits broad cosmetic panels; state crossing angle, line density, coverage area, and the approved visual sample.

Satin Non-Woven Brushing

Satin brushing uses non-woven abrasive media to produce a softer, diffuse sheen. It suits radiused external surfaces; specify media grade, permitted edge roll-off, and whether machining marks must be removed.

Grain Grade And Localized Patterns

Coarse grain is more visibly linear, while fine grain is quieter and shows small defects differently. For logos, stripes, or masked zones, define grit or equivalent sample, grain direction, exact extents, masking transitions, and inspection lighting.

Material Selection Matrix

A 120–180 grit belt is a common starting convention, but the approved sample should define appearance and grain consistency.

Oxide And Protection

Aluminum forms an oxide layer; brass and copper can tarnish; carbon steel can rust. Clear coating, passivation, plating, or controlled storage may be appropriate only after environmental validation.

Stainless and nickel-bearing grades need application-specific corrosion review, especially where chlorides, cleaning chemicals, or trapped moisture are present.

Define The Cosmetic Zone

A drawing note should identify each brushed face, direction arrow, stop line, and non-cosmetic boundary. Require masking where grain must not enter sealing lands, bores, threads, datum surfaces, or mating features.

• State visible assembly orientation
• Dimension masking boundaries from datums
• Specify edge break before brushing

Control Marks And Sequence

Laser marks usually follow brushing when a crisp, contrasting mark is required; engraving before brushing can soften edges or collect abrasive residue. Anodizing, plating, clear coats, and conversion treatments can alter sheen, so trial panels or first-article approval are needed for appearance-critical combinations.

Lock The Lot Standard

One retained master sample, dated process note, and revision-controlled drawing create a practical cross-lot reference. Record abrasive family, direction, fixture orientation, protected areas, and inspection lighting; reapprove the finish when material, geometry, coating, or process route changes.

Grain And Assembly Direction

One grain direction should be identified from a drawing datum or a marked view. Mating visible faces need continuous, intentional line flow; a change at a seam requires explicit approval.

A reference sample establishes acceptable grain density, sheen, and line continuity when words alone are insufficient.

Geometry And Defect Control

Tight inside corners, deep pockets, raised lettering, and narrow slots restrict abrasive access. The drawing should define whether unmatched corner texture, transition lines, or local hand finishing are acceptable.

All cosmetic zones require burr removal without rolled edges, drag marks, embedded abrasive, scratches, staining, or residual compound.

Inspection And Protection

A cosmetic-zone map should distinguish customer-visible faces from functional or concealed surfaces. Specify viewing distance, angle, lighting, reference sample, and acceptance limits for scratches, color variation, and grain breaks.

Clean gloves, interleaving film, and protected packaging prevent fingerprinting and contact damage after final inspection. SUUXIANG should align the inspection record and packing method with the approved drawing revision.

Verify Relevant Experience

Two representative samples should match the alloy, grain direction, geometry, and viewing condition of the intended part.

One drawing review should identify tool access, protected faces, masking needs, and finish-after-machining constraints.

• Ask for sample inspection criteria.
• Ask which faces are cosmetic.
• Ask how grain direction is controlled.

Confirm Process Ownership

One route sheet should state whether brushing is performed in-house or by a qualified finishing partner.

Two evidence sets matter: traveler traceability through finishing and acceptance records for the returned lot.

• Who owns final cosmetic approval?
• How are lots identified?
• What triggers corrective action?

Test Communication And Delivery

Three pre-award questions reveal control: What is the sample plan? How are revisions frozen? How are rejects contained?

One packaging specification should prevent face-to-face abrasion, mixed lots, and grain-direction damage during shipment.

• Request DFM constraints in writing.
• Confirm capacity against the delivery date.
• Define photo-based cosmetic inspection.

Define The Visual Standard

One word—brushed—does not define abrasive grade, grain spacing, sheen, or allowable marks; prototype and production lots can therefore look different. Specify a retained limit sample, viewing distance, lighting, grain direction, and acceptance boundaries.

Two photos are useful references but cannot reliably show tactile texture, color shift, or directional reflection. Approve a physical first article or coupon and record its revision with the order.

Design For Brush Access

Three defects—tool marks, EDM pits, and deep scratches—will remain visible because brushing is not corrective stock removal. Set the pre-finish surface condition and identify any permitted blend area before machining.

Four geometry risks—deep pockets, sharp internal corners, ribs, and obstructed lettering—prevent a uniform abrasive path. Review tool access during DFM, add radii or relief where possible, and define excluded surfaces.

Control Material And Delivery

Five material changes can alter grain contrast, stain behavior, and corrosion performance even when the part geometry is unchanged. Freeze alloy, heat-treatment state, and corrosion environment before sample approval.

Six packaging failures can scratch grain during handling or shipment, creating rejectable cosmetic damage. Define protective film compatibility, separators, orientation, clean handling, and pack-out inspection in the RFQ.

Define The Cosmetic Zone

Step 1: Mark every customer-visible face, grain direction, masked area, and edge break on the 2D drawing. Identify exposure to fingerprints, abrasion, moisture, cleaners, or assembly contact.

Step 2: State whether connector-tooling or mold-component faces are cosmetic, functional, or both. Keep sealing, bearing, and datum surfaces outside the brushed zone unless the design specifically permits it.

Build A Reviewable RFQ

Step 3: Submit the 2D drawing, 3D model, material, heat-treatment sequence, quantity, target texture, and a retained reference sample or approved photograph. Define whether sample appearance overrides a written roughness value.

Step 4: Request DFM feedback on tool access, brushing direction across radii, EDM or grinding allowances, and finish-before-or-after machining. Resolve conflicts before prototype release.

Approve And Control Production

Step 5: Evaluate a first article under the agreed viewing conditions against the sample, grain continuity, dimensions, and critical datums. Approve the inspection method and acceptance boundaries in writing.

Step 6: Lock the process route, abrasive specification, handling, protective film, packaging orientation, and revision identifier. For repeat low-volume CNC orders, require lot traceability and review any material, process, or supplier change before release.