How a Waterjet Actually Works
Why watch: See how high-pressure water and abrasive erode metal without a heat-affected zone — the same idea behind blanking thick aluminum plate.
Typical metallic path for 707-family airframe parts. Exact sequence and machines live in the work order and approved process specs — this is orientation, not a traveler.
Each machine section below includes at least one embedded process demo (youtube-nocookie). Clips are public how-it-works videos — general industry process, not E-3/E-6 or Boeing-specific training.
Watch the process
Jump to a station and play the embedded demo. More curated clips live on the Videos pages.
Shop reality
Not every part hits every station. Soft-state form, then age; or machine from heat-treated plate. Follow the traveler. Do not invent process order from this page.
Cut sheet and plate to near-net blanks before form or machine. CNC routers handle aluminum sheet stacks with vacuum hold-down; abrasive waterjet cuts thicker plate without heat-affected zones. Leave stock for trim after form when the process calls for it.
Why watch: See how high-pressure water and abrasive erode metal without a heat-affected zone — the same idea behind blanking thick aluminum plate.
Jaws grip the blank and pull it over a male stretch die. Common for compound-curve skins and large panels. Jaw inserts and side stops protect edges; optional bulldozer assists local radii. Form in the temper the process specifies — usually soft or underaged — then heat treat.
Why watch: Watch jaws pull sheet over a male die — the core motion of aerospace stretch presses.
Rubber diaphragm (or fluid cell) presses the blank over a male block. One hard tool half — pins locate, blank outline matches the block. High pressure fills contours without mating female dies. Typical for frames, webs, brackets, and low-volume airframe details.
Why watch: Quintus airframe hydroform overview — diaphragm/fluid-cell forming against a male block.
Why watch: Short principle animation of fluid-cell / Flexform motion so the press cycle is clear.
V-die and punch bend flanges and channels. Backgauge sets bend lines. Good for straight-line bends on sheet and light plate; not a substitute for stretch or hydro when compound contour is required.
Why watch: Punch, V-die, and backgauge basics for straight-line flange work.
Pyramid or pinch rolls put cylindrical or conical curvature into sheet and light plate — ducts, leading-edge skins, and rolled sections. Feed slowly; watch for edge ripple and oil-canning.
Why watch: Step-by-step rolling of sheet into a cylinder on a four-roll machine — same family of motion as shop pinch/pyramid rolls.
Matched dies with a falling hammer form deep draws and complex contours in soft aluminum. Older shop workhorse still seen on sustainment lines when hydro capacity or tooling history points that way.
Why watch: Matched-die drop-hammer forming in action — progressive blows over male/female tooling.
When you want one clip that ties brake, stretch, and related sheet processes together before diving deeper on the Videos pages.
Why watch: Broad mechanical-metallurgy overview of sheet forming modes — good context for the form stations above.
Solution heat treat, quench, and age set final temper after forming in a workable condition. Furnaces, quench tanks, and aging ovens are special processes — calibrated, surveyed, and controlled. Distortion after quench is real; fixture quench or straighten per approved methods only.
Why watch: Solution treat → quench → age explained for heat-treatable aluminum — the language behind T-tempers on the traveler.
Chemical milling thins aluminum to pocketed skins and weight-reduced webs. Mask, etch, rinse, and demask under controlled bath chemistry. Thickness maps and etch rates belong to process engineering — not the shop floor guess.
Why watch: Educational overview of non-traditional machining including chemical milling (mask + etch). General process context only.
Machine fittings, spars, and thick plate details. Tombstones and vacuum tables hold work; spar fixtures set datums for long parts. Long-bed mills handle wing and fuselage length structure. Coolant, tool life, and surface finish callouts come from the NC package and material specs.
Why watch: Large-structure aerospace machining / wing-factory context for long-bed and multi-axis work.
Pneumatic drill motors, drill cages, and bushing plates put fastener holes on location. Microstop countersinks control depth for flush heads. Start reamers and final reamers size holes for cold work or fastener fit per the drawing.
Why watch: Hole prep, countersink, and flush riveting context — why hole quality matters before fasteners go in.
Hydraulic pullers draw a tapered mandrel through a lubricated split sleeve to cold-expand holes. Used heavily on fatigue-critical structure and life-extension programs. Sleeve, mandrel, nosecap, and hole size must match the FTI (or approved) process — no improvising.
Why watch: Mandrel, sleeve, and puller sequence for hole cold expansion — the hardware behind fatigue life extension work.
Controlled shot peening puts compressive residual stress in surfaces and hole edges where called out. Intensity, coverage, and media are process-controlled. Almen strips verify intensity — not “until it looks peened.”
Why watch: NPTEL lecture on peening mechanics, residual compression, and why intensity/coverage are controlled — not cosmetic blast.
Conversion coating (Alodine-class) or anodize for corrosion protection and paint adhesion. Clean, coat, rinse, and seal per the finish process. Protect Alclad — do not sand through cladding to “fit” a finish.
Why watch: Electrochemical oxide growth on aluminum — sister finish family to conversion coatings (Alodine/chem film). General process, not a shop recipe.
Nondestructive inspection closes the loop: penetrant, eddy current, ultrasonic, or radiography as the drawing and process require. Inspectors work to approved techniques and acceptance criteria — manufacturing does not “NDI itself.”
Why watch: Clear penetrant / developer walkthrough — one common NDI method for surface-breaking discontinuities on aluminum.