Mill Precision

Cut to micron.
Shipped in 48 hours.

Material
6061-T6 Aluminum
Tolerance
±0.001″ / ±0.025mm
Process
5-Axis Simultaneous
Hydraulic Valve Body Assembly — Exploded View
Transparent Process

Watch a hydraulic valve body
go from billet to CMM report.

Seven phases. Every decision visible. This is exactly how your part gets made — fixturing strategy, chip loads, inspection data. Nothing is a black box.

Scroll through each phase
Phase
01/7
01 — Raw Billet6061-T6 · 4.5″ × 3.2″ × 2.8″

Stock arrives pre-inspected.

Mill sources certified 6061-T6 aluminum billet with full material certs. Each bar is measured on receipt — dimensions, hardness, alloy verification via XRF. No surprises in the middle of a run.

Billet weight
2.84 kg
Stock allowance
+3.0mm all faces
Material cert
MTR included
02 — First-Op Roughing

80% of material removed in Op-1.

Aggressive roughing with 0.040″ radial stepover and optimized toolpaths leaves 0.015″ stock on all walls. Chip load is dialed per alloy — no chatter, no recutting. Cycle time: 12 minutes.

Chip load
0.004″/tooth
Stepover
40% cutter dia.
Stock remaining
0.015″ all walls

3/4″ Carbide · 8000 RPM · 180 IPM

03 — Fixture Flip

Fixturing strategy documented, shared.

Custom soft jaws machined in-house hold the part from Op-1 datum features. The 4th axis indexes to hit all five faces in a single setup — no re-clamp error, no datum shift. Fixture drawing included in your job package.

Setup change
< 8 min
Re-clamp error
< 0.0005″
Fixture type
Custom soft jaw

Custom soft jaw · 4th axis index

04 — Finish Pass

Final geometry cut to print.

Finish passes run with 1/4″ ball endmill at 12,000 RPM, 0.0005″ radial depth. Bores are single-point bored to H7 tolerance. Surface finish measured with profilometer — Ra 0.8μm on critical faces.

Surface finish
Ra 0.8μm
Bore tolerance
H7 (+0.000/+0.013mm)
Final stock
0.000″ ± 0.001″

Ra 0.8μm · 0.0005″ stock

05 — Deburr & Edge Break

Every edge touched by hand.

Bench deburr on all accessible edges with 45° chamfer tool and hand stone. Internal bores get a custom deburring tool run through by CNC. No burr escapes. Parts are bagged individually after inspection.

Edge break
0.005″ × 45° all edges
Internal ports
CNC deburr tool
Packaging
Individual VCI bag

0.005″ × 45° · All edges

28.013mm
06 — CMM Inspection

Data, not assurance.

Every first article gets a full CMM report on our Zeiss Contura. 47 features measured. The report ships with your parts as a PDF — nominal, actual, deviation, pass/fail on every callout. No black box.

CMM machine
Zeiss Contura G2
Features measured
47 per part
Report format
FAIR / AS9102 PDF

Zeiss Contura · 100% first article

07 — Ship

48-hour first articles, door to door.

Parts are crated in custom foam, labeled with part number, revision, and material cert reference. CMM report is in the box. FedEx Priority for first articles — you have the part before your next stand-up.

First article lead
48 hours
Production runs
5–15 business days
Packaging
Custom foam crate

FedEx Priority · Crated + labeled

Every procurement engineer's next question:

"How does Mill compare to
what I'm already doing?"

See the comparison
Comparison

Why procurement engineers
choose Mill.

Three decisions every sourcing manager faces. Here's what the choice actually looks like.

Millvs.Overseas Brokers
Overseas Broker
  • 4–8 week lead times, optimistically
  • Quote is a single number, no breakdown
  • DFM feedback arrives after tooling is cut
  • Material certs are generic or missing
  • Inspection: "We checked it"
  • Re-order requires re-quoting from scratch
Mill
  • 48-hour first articles. 5–15 days production.
  • Line-item quote: setup, cycle time, material, inspection
  • DFM markup returned as annotated PDF before you commit
  • Full MTRs included. XRF verification available.
  • CMM report with every first article, 47 features measured
  • Part file + fixture + program archived. Re-order in 24 hours.
Millvs.In-House Machine Shops
In-House Shop
  • Production orders compete with your prototype for machine time
  • Setup costs buried in overhead, invisible to engineering
  • Operator knowledge leaves when the machinist does
  • CMM is shared, queued, often skipped on "trusted" parts
  • Tooling decisions made on habit, not data
Mill
  • Dedicated capacity. Your prototype doesn't wait for production.
  • Setup costs are a line item. Engineering sees the real cost of complexity.
  • Every job is documented — program, fixture, toolpath, notes.
  • CMM on every first article. Production sampling available.
  • Toolpath strategy is engineered per job, not defaulted.
Millvs.Instant-Quote Platforms
Online Platforms
  • Algorithm quotes from STEP geometry — no DFM review
  • Tight tolerances trigger 3–5× price multipliers, unexplained
  • Your file routes to a network shop. You don't know who.
  • Quality questions go to a support ticket, not a machinist
  • Inspection data available at extra cost, if at all
Mill
  • Engineer reviews your file. DFM notes returned same day.
  • Tight tolerance costs are explained — bore grinding vs. boring, etc.
  • You know exactly which machines and who runs them.
  • Call the shop. Talk to the programmer who's cutting your part.
  • CMM report ships with the part. No upsell.
Materials & Capabilities

If it machines,
we cut it.

Six material families. Four machine types. One shop. Tolerances from ±0.001″ on production runs to ±0.0002″ on first articles with CMM verification.

Ra 0.4μm achievable

Aluminum

6061-T6 · 7075-T651 · 2024-T4 · 5052

Anodize · Alodine · Bare

Ra 0.8μm standard

Steel

4140 · 4340 · 1018 · 17-4 PH

Black oxide · Zinc plate · Passivate

Ra 0.4μm electropolish

Stainless

303 · 304 · 316L · 17-4 PH

Passivation · Electropolish

Ra 0.8μm

Titanium

Grade 2 · Grade 5 (Ti-6Al-4V)

Anodize Type II · Bare

Ra 1.6μm standard

Plastics

Delrin · PEEK · Nylon · UHMW

Machined to print

Ra 0.8μm

Exotic

Inconel 718 · Hastelloy C276

Aerospace / Energy

5-Axis Simultaneous
DMG Mori DMU 50 · DMU 60 eVo
3+2 Indexed
Haas VF-4 · VF-6 · ST-30
Turning
Haas ST-30 · 12″ chuck · Live tooling
CMM Inspection
Zeiss Contura G2 · FAIR reports
Wire EDM
Mitsubishi MV2400-S · ±0.0001″
Surface Grinding
Chevalier FSG-2A818 · ±0.0001″
Linear tolerance
±0.001″ / ±0.025mm
Bore tolerance
H6/H7 achievable
Flatness
0.0005″ / 0.013mm
Surface finish
Ra 0.4μm achievable
Check Your Tolerances →
±0.001″
Tightest held tolerance in production
48 hrs
First article lead time, door to door
100%
CMM inspection on all first articles
5-Axis
Simultaneous machining, all geometries
Industries Served

The parts that end up in
things that matter.

From first-article aerospace brackets to emergency replacement shaft collars at 2 AM — if the part needs to be right, it comes to Mill.

Aerospace

AS9102 FAIR · AMS material specs · Traceability

Brackets · Fittings · Actuator housings

Hydraulics

Manifolds · Valve bodies · Cylinder ends

H7 bores · Cross-drilled ports · O-ring grooves

Medical

Surgical jigs · Implant trials · Fixture plates

PEEK · Ti-6Al-4V · 316L · Passivated

Robotics

Structural frames · Gearbox housings · End effectors

Low-weight · Tight stack-up · Prototype speed

Bottling / Packaging

Obsolete part reverse engineering · Shaft collars · Cams

Sample-to-part · 24-hour turnaround available

Defense

ITAR-compliant shop · Controlled documentation

Weapon mounts · Optic rails · Structural brackets

Get a Quote

Upload your part.
Get a real answer.

Drop your STEP or IGES file. A machinist reviews it — not an algorithm. DFM notes back same day. Line-item quote within 24 hours.

01
Upload STEP/IGES or send a drawing
We accept .step .stp .iges .igs .pdf .dxf
02
Machinist reviews your file
DFM notes returned same day as annotated PDF
03
Line-item quote in 24 hours
Setup · cycle time · material · inspection — all visible
04
48-hour first article
CMM report ships with the part. No upsell.

Still working from prints?

Send Us a Drawing

drawings@mill.co — PDF, DXF, or even a photo of a print

Drop STEP / IGES / PDF here

.step · .stp · .iges · .igs · .pdf · .dxf

or click to browse

Files are kept confidential. NDA available on request.
Response within 4 business hours during shop hours (6 AM – 10 PM EST).