Surface Treatment for Precision Parts — Anodize, Plate, Coat, Protect.
Factorem applies surface treatments — anodizing, chromate, passivation, electroless nickel, and more — as part of the same engineering workflow as machining and fabrication. One team, one quote, one quality pack.
MIL-spec
Standards supported
5–75µm
Anodize thickness range
3–7 days
Finishing lead time
ISO 9001
Certified
Typical Treatment Specs
Common parameters for surface treatment at Factorem. Confirm your specific standard and material with our engineers before ordering.
Anodize Type II Thickness
5–25µm
Per MIL-A-8625 Type II. Clear, colour, and black available. Dyeable.
Anodize Type III (Hard Coat)
25–75µm
Per MIL-A-8625 Type III. Hardness ~400–600 HV. Wear and abrasion resistant.
Chromate (Alodine) Class
1A / 3
MIL-DTL-5541. Class 1A for max corrosion protection; Class 3 for low electrical resistance.
Electroless Nickel Thickness
5–50µm
Per AMS 2404 / ASTM B733. Uniform deposit on all surfaces — suitable for complex geometries.
Passivation Standard
ASTM A380
For stainless steel parts. Removes free iron and improves natural corrosion resistance. ASTM A967 available.
Lead Time (finishing)
3–7 days
When added to a machining or sheet metal order. Standalone finishing orders reviewed on request.
Common Treatments
Treatments we apply regularly — this isn't an exhaustive list. If you have a spec not shown here, share it and we'll confirm.
Anodize — Type II & Type III
- ·Type II: corrosion protection, clear / black / colour dye
- ·Type III hard coat: wear resistance, high-cycle parts
- ·Accounts for ~50% surface growth — flagged in DFM review
Standard: MIL-A-8625 Type II / III
Chromate Conversion (Alodine)
- ·Corrosion protection; electrically conductive (unlike anodize)
- ·Class 1A (max protection) or Class 3 (low resistance)
- ·Thin film — minimal dimensional impact
Standard: MIL-DTL-5541 Class 1A / 3
Electroless Nickel Plating
- ·Uniform deposit on all surfaces, including internal bores
- ·Aluminium, steel, copper alloys
- ·High-phos (corrosion) or mid-phos (general use)
Standard: AMS 2404 / ASTM B733
Passivation
- ·Restores chromium oxide layer; removes surface contamination
- ·No dimensional change
- ·Medical, vacuum, and food-grade applications
Standard: ASTM A380 / A967
Powder Coat & Liquid Paint
- ·Durable decorative finish; RAL colours available
- ·Liquid paint for complex geometries or colour matching
- ·Enclosures, frames, structural panels
Something else?
Bead blast, vibratory deburring, black oxide, gold plating, PTFE, Parylene — and others. If you have a spec, share it. Most treatments not listed here can be sourced through our supplier network.
Don't see what you need?
Unusual alloy, non-standard specification, or a combination of treatments? Our engineers review non-standard finishing requests — most can be accommodated.
Industries & Applications
Surface treatment is applied across all of Factorem's served verticals. Commonly used across these industries — but not limited to them.
Photonics & Optics
Black anodize for stray-light suppression on optical mounts and lens tubes; chromate on aluminium breadboard components for conductivity; bead blast for low-reflectance surfaces
See Photonics page →
Quantum
Electroless nickel on cryogenic mounts for low outgassing; passivation on stainless vacuum components; Class 3 chromate for RF cavity flanges requiring electrical continuity
See Quantum page →
Robotics
Hard anodize (Type III) on high-wear end-effector components; powder coat on mild steel structural frames; anodize on aluminium enclosures and panel components
See Robotics page →
Defense & Aerospace
MIL-spec anodize and chromate on avionics enclosures; passivation on stainless fasteners and brackets; Class 1A chromate on aluminium structural parts — all with full CoC documentation
See Defense page →
Space Tech
Low-outgassing anodize on satellite structural panels; chromate on aluminium attitude control hardware; passivation on stainless propulsion components — vacuum-compatible processes available
See Space Tech page →
Other Applications
Medical device components, semiconductor tooling, cleanroom fixtures, industrial automation parts — if it needs a coating, we can work with you on the right specification.
Before You Send
Design Considerations
Four things worth checking before you finalise your drawing. Our DFM review covers these — but flagging them upfront saves time.
Account for coating buildup
Anodize and plating add material — Type II adds ~5–25µm per surface, Type III up to 38µm, EN up to 50µm. Machine tight-tolerance features to pre-treatment dims. Specify post-treatment dimensions on your drawing; we'll work back from there.
Mask critical surfaces
Threads, precision bores, and sealing faces can be masked to stay in machined condition. Note them on your drawing (e.g. "mask M5 holes"). Our DFM review flags anything that likely needs masking.
Surface finish follows the substrate
Coatings don't hide machining marks. Decorative anodize or bright plating needs Ra 0.8µm or better as-machined. Specify finish on your drawing and we'll confirm suitability.
Alloy matters
6061 and 7075 anodize well. 2024 varies. Cast alloys typically can't hard-anodize to a cosmetic standard. Call out your alloy on the drawing — we'll advise if there are any process constraints.
Something not on this list? Send your drawing and we'll review it →
How a Finishing Order Works
Specify Treatment on Your Drawing
Include finish specification (e.g. "Anodize per MIL-A-8625 Type III, 25µm, black"), alloy, and any masking requirements. Upload with your STEP or DXF file.
DFM Review — Finish & Pre-Treatment Dimensions
Our engineer confirms treatment compatibility, flags tight-tolerance features that need masking or adjusted pre-treat dimensions, and confirms alloy suitability for the specified process.
Confirm Quote & Specification
Fixed-price quote covering machining + finishing as a single order. Confirm treatment standard, class, colour, and masking requirements before production starts.
Machine → Pre-Treat → Coat → Inspect
Parts are machined to pre-treatment dimensions, pre-treated (clean, etch, activate), then treated to spec. Coating thickness and appearance checked before release. First articles inspected against your drawing.
Documentation & Delivery
Certificate of Conformance to the treatment standard on every order. Coating thickness test reports and process certifications available on request. Tracked shipment with full handover pack.
Surface Treatment FAQ
We offer anodizing (Type II and Type III hard coat), chromate conversion (Alodine/Iridite), electroless nickel plating, passivation, powder coating, liquid paint, bead blasting, and vibratory deburring. Most machined or sheet metal orders can be finished in the same workflow. Contact us if you need a process not listed — most can be sourced through our supplier network.
Type II (sulphuric anodize) produces a thin oxide layer (5–25µm) suitable for general corrosion resistance and dyeing. Type III (hard anodize) produces a thicker, harder layer (25–75µm) with higher wear resistance, used for sliding surfaces, wear pads, and high-cycle parts. Type III affects tight-tolerance features more significantly — our DFM review flags these before processing.
Yes. The anodize layer grows into and out of the aluminium surface roughly 50/50. Type II adds approximately 5–25µm per surface; Type III adds 12–38µm per surface. Tight-tolerance bores, threads, and mating features need to account for this. Specify critical features on your drawing and we'll advise on pre-anodize dimensions.
Yes. Threaded holes, precision bores, and sealing surfaces can be masked before anodizing or plating to maintain dimensions. Specify masking requirements on your drawing or in your order notes. Our DFM review will flag critical features and confirm the masking strategy before processing.
Chromate conversion coating (MIL-DTL-5541) is applied to aluminium alloys. It provides corrosion protection and a conductive surface — unlike anodizing, chromate does not significantly affect electrical conductivity. Class 1A is for maximum corrosion protection; Class 3 is for parts requiring low electrical resistance. Both are available.
Standard documentation includes a Certificate of Conformance to the specified standard (e.g. MIL-A-8625 for anodize, MIL-DTL-5541 for chromate, ASTM A380 for passivation). Coating thickness test reports and process certifications are available on request. Full quality documentation pack available for aerospace and defense programs.
Ready to Finish Your Parts?
Upload your drawing with a finish specification for a combined machining + treatment quote — or talk to an engineer first about your requirements.
DFM review within 24 hours · Fixed-price quote · Certificate of Conformance on every order
