Custom extrusion & die development
From your drawing to a first article, without a die that never balances
The number most suppliers quote is the die lead time. The number that decides your project is how many trials it takes before the section runs true — because every extra trial is a week you did not plan for. Here is the whole path with day counts, what you receive at each step, and what we need from you to keep it on schedule.
on 6063 soft alloy
The actual sequence
Seven steps, and what is in your hands after each
A quotation usually collapses this into “die 7 days, production 15 days”. The detail matters because the two places projects slip are the feasibility reply and the first trial — not the machining of the die itself.
- Day 0you send
Section review
Send a CAD file, a dimensioned PDF, or a hand sketch with numbers on it. We read it for three things before anything else: circumscribing circle against our largest press, minimum wall for the alloy, and tongue or fin ratios that will not fill.
You get: a written feasibility reply within one working day — including a no, if it is a no.
- Day 1–2we quote
Die type and tooling cost
The die type follows the section, not our preference: a solid or semi-hollow shape runs on a flat die, a closed hollow needs a porthole, and a wide thin-walled hollow usually needs a bridge die with a welded chamber. Each has a different tooling cost and a different scrap rate on the first run.
You get: die cost as a separate one-time line, unit price per metre at your quantity, and the press the profile will run on.
- Day 2–5we cut
Die manufacture
H13 tool steel, cut on CNC die-sinking EDM and wire EDM, vacuum heat-treated to HRC 48–52 and tempered three times so the bearing lands do not move after the first heat cycle. Soft-alloy dies are ready in 5–7 days; 6061 and harder sections take 10–14 because the bearing length and nitriding have to be more conservative.
You get: the die number, stamped and recorded on a die card that follows the tool for its whole life.
- Day 5–7we trial
First trial extrusion
The die goes into the press with a pre-heat to 450–480 °C. We pull the first two metres, measure wall thickness at eight points, check twist over the full length, and look at the bearing marks. If the metal is running faster on one side, the bearing is corrected and the die goes back in — this is normal, and it is why a single trial is not a guarantee.
You get: the first-article sample plus a dimensional report on those two metres.
- Day 7–10you approve
Sample approval
Check the sample against your assembly, not only against the drawing. Fit problems that pass a drawing usually show up at a corner joint, a sliding fit, or a gasket groove. Once you sign, the die is locked and the bearing settings are recorded so a re-order reproduces the same section.
You get: a signed approval that becomes the reference for every later batch.
- +10–15we run
Production
Full run on the same press, with the die settings from the approved trial. Billet alloy is verified by spectrometer before the run, and the first lengths off the press are checked before the rest of the order is committed.
You get: lengths cut to your tolerance, with the batch inspection record.
- +3–7finish
Finishing and packing
Powder coating, anodizing or machining runs in parallel where the sequence allows it. If a feature has to stay conductive or thread-clean, it is masked or plugged here — not after the fact.
You get: packed lengths with the coating report and material certificate.
The part nobody puts in writing
Die cost and die ownership, stated plainly
Tooling arguments surface in year two, when a buyer wants a second source or the profile changes. These are the terms we work to; if a supplier will not answer these six lines in writing, that is your answer.
| Question | Our position |
|---|---|
| Who pays for the die? | You do, as a one-time tooling charge shown separately from the unit price. We do not hide tooling inside the per-metre rate — that makes the die impossible to value and impossible to take with you. |
| Is it refundable? | Yes, on an agreed volume. Once the cumulative order passes that volume the tooling charge is credited back against invoices. |
| Who owns it? | You do, from the moment it is paid. We hold it as bailee: we store it, maintain it, and release it on request, including to another extruder. |
| What if the profile changes? | Minor changes — a radius, a screw boss, a groove depth — are usually corrected on the existing die. A change to the outer envelope or the wall ratio normally needs a new die, and we will say which before you commit. |
| What if it fails early? | A die that fails inside its expected life from a manufacturing fault is replaced at our cost. A die that fails from foreign metal in the billet is a different conversation, and the inspection record tells us which one it was. |
| What if I leave? | We crate the die and release it. No retention fee, no condition that you keep ordering from us. The die card goes with it. |
Cost drivers
Six things on your drawing that set the price
Two sections of the same weight can differ by 40% in unit price. It is almost never the alloy. It is these six, and five of them are decided before the drawing reaches us.
- Circumscribing circleThe smallest circle the section fits inside. It picks the press, and the press sets the hourly rate the profile has to carry. Going from 180 mm to 260 mm can move a section up a whole press class.
- Wall thickness, and how even it isA uniform 1.6 mm wall extrudes faster and straighter than a section that runs 1.2 mm on one face and 3.0 mm on the other. Uneven walls pull the metal to the thick side and cost you straightness.
- Tongue and fin ratiosA tongue narrower than about 1:3, or a fin gap under 2.5 mm, needs a die that wears faster and runs slower. This is the single most common reason a cheap quote becomes an expensive part.
- Tolerance classEN 755-9 general versus EN 12020-2 precision is not a paperwork difference — it changes bearing length, run speed and scrap rate. Specifying precision when general would do is a real cost; specifying general and hoping is a real risk.
- Alloy and temper6063-T5 runs at 8–60 m/min depending on section. 6061-T6 needs slower speeds and more conservative bearings, so the same shape costs more in 6061 — even though the metal is only marginally dearer.
- Finish and maskingA mill-finish length is one operation. Anodizing adds racking marks and colour control; powder adds film thickness and edge coverage; machining after finishing adds masking. Each is a separate pass through the line.
Straight answers
Why a first trial fails, and what happens next
A supplier who claims a clean first article every time is either running only simple sections or not measuring. These are the four we see, in order of frequency.
- Feed imbalance
Metal reaches one side of the bearing faster, so the wall runs thin on that side and thick on the other. Corrected by adjusting bearing length — usually one extra trial, occasionally two.
- Twist over length
Common on asymmetric sections and on anything with a long open leg. Sometimes a die fix, sometimes a run-out table and puller setting. We check twist on the full 2 m, not on a 300 mm cut, because twist accumulates.
- Die lines on a visible face
Bearing marks that would telegraph through a 60 µm powder coat. Fixed by polishing the bearing, but if the face is decorative it is better to design the mark onto a hidden face at the drawing stage.
- Insufficient fill in a tight corner
A sharp internal corner with a thin wall simply will not fill at production speed. The honest fix is a radius on the drawing, and we will propose one rather than run a die that only works slowly.
