Tolerances, alloys and sizing capabilities
Everything an engineer needs before releasing a drawing to us. All tolerances follow EN 755-9 / IS 2673 for material in the as-extruded and aged condition, measured at 20 °C. Closer tolerances can be held on request — confirm at the enquiry stage so the die is designed accordingly.
What we can extrude
Maximum sizes currently extrudable on our 1,100 MT press. A section must fit inside the circumscribing circle and its extrusion ratio must suit the press — our tool room reviews every new drawing.
| Profile type | Maximum size |
|---|---|
| Square tube | 100 × 100 mm |
| Round tube | Ø 110 × 6 mm |
| Rectangular tube | 150 × 50 mm |
| Flat bar | 175 × 6 mm |
| Square bar | 50 × 50 mm |
| Round bar | Ø 52 mm |
| Press & billet data | Specification |
|---|---|
| Extrusion press capacity | 1,100 Metric Tonnes |
| Container / billet diameter | 6 inch (152 mm) |
| Maximum circumscribing circle | 180 mm |
| Maximum extruded length | 6,500 mm |
| Minimum wall thickness | 0.80 mm, subject to section shape |
| Tempers | T4, T5, T6 |
| Finishes | Mill, anodised, powder coated, wood finish |
Standard mill lengths are 3,000 mm, 3,660 mm (12 ft), 4,880 mm (16 ft) and 6,000 mm; any cut length within range to order. Ends are square-cut and deburred as standard.
Dimensional & form tolerances
Quoted to EN 755-9 / IS 2673. Select a category.
Tolerance on cross-sectional dimensions
Dimension A — not affected by wall thickness · Dimension B — across a metal-enclosed (hollow) space.
| Nominal dimension (mm) | Tolerance — dimension A | Tolerance — dimension B |
|---|---|---|
| up to 3.00 | ± 0.15 | ± 0.25 |
| over 3.00 to 6.00 | ± 0.15 | ± 0.30 |
| over 6.00 to 10.00 | ± 0.20 | ± 0.35 |
| over 10.00 to 15.00 | ± 0.20 | ± 0.40 |
| over 15.00 to 20.00 | ± 0.25 | ± 0.45 |
| over 20.00 to 30.00 | ± 0.25 | ± 0.50 |
| over 30.00 to 45.00 | ± 0.30 | ± 0.60 |
| over 45.00 to 60.00 | ± 0.35 | ± 0.70 |
| over 60.00 to 90.00 | ± 0.40 | ± 0.85 |
| over 90.00 to 120.00 | ± 0.50 | ± 1.00 |
| over 120.00 to 150.00 | ± 0.60 | ± 1.20 |
| over 150.00 to 180.00 | ± 0.70 | ± 1.40 |
| over 180.00 to 250.00 | ± 0.90 | ± 1.70 |
| over 250.00 to 300.00 | ± 1.10 | ± 2.00 |
Dimension A is not influenced by die deflection across a hollow. Dimension B spans a metal-enclosed space and carries a wider tolerance because both the mandrel and the die can move under pressure.
Wall thickness tolerance
| Nominal wall thickness (mm) | Open profile | Hollow profile |
|---|---|---|
| up to 1.50 | ± 0.15 | ± 0.20 |
| over 1.50 to 3.00 | ± 0.20 | ± 0.25 |
| over 3.00 to 6.00 | ± 0.25 | ± 0.35 |
| over 6.00 to 10.00 | ± 0.35 | ± 0.50 |
| over 10.00 to 15.00 | ± 0.45 | ± 0.65 |
| over 15.00 to 20.00 | ± 0.60 | ± 0.85 |
| over 20.00 to 30.00 | ± 0.80 | ± 1.10 |
Where a wall is thinner than one-third of the maximum wall in the same section, or the section carries a very wide circumscribing circle, the tolerance is agreed case by case before the die is cut.
Cut length tolerance
| Cut length (mm) | Standard tolerance | Precision cut, on request |
|---|---|---|
| up to 1,000 | + 2.0 / – 0 | ± 0.5 |
| over 1,000 to 2,000 | + 3.0 / – 0 | ± 0.5 |
| over 2,000 to 4,000 | + 4.0 / – 0 | ± 1.0 |
| over 4,000 to 6,000 | + 5.0 / – 0 | ± 1.0 |
| over 6,000 to 8,000 | + 6.0 / – 0 | ± 1.5 |
| over 8,000 | + 8.0 / – 0 | on agreement |
Straightness (bow)
| Length of piece (m) | Deviation over any 300 mm — max | Deviation over full length — max |
|---|---|---|
| up to 1.0 | 0.30 | 0.30 |
| over 1.0 to 2.0 | 0.30 | 0.60 |
| over 2.0 to 3.0 | 0.30 | 0.90 |
| over 3.0 to 4.0 | 0.30 | 1.20 |
| over 4.0 to 5.0 | 0.30 | 1.50 |
| over 5.0 to 6.5 | 0.30 | 2.00 |
Convexity & concavity (flatness of a face)
| Width of face W (mm) | Max deviation from flat — convex or concave (mm) |
|---|---|
| up to 25 | 0.20 |
| over 25 to 50 | 0.30 |
| over 50 to 100 | 0.50 |
| over 100 to 150 | 0.70 |
| over 150 to 200 | 0.90 |
| over 200 to 300 | 1.20 |
Contour (curved and shaped surfaces)
| Width across curved surface W (mm) | Max gap g against contour gauge (mm) |
|---|---|
| up to 25 | 0.30 |
| over 25 to 50 | 0.45 |
| over 50 to 100 | 0.70 |
| over 100 to 150 | 0.90 |
| over 150 to 200 | 1.20 |
Twist
Laid on a surface plate, the rise of the free corner is the twist — controlled by the stretcher.
| Width of profile (mm) | Twist per metre — max (mm) | Twist over full length — max (mm) |
|---|---|---|
| up to 30 | 1.0 | 3.0 |
| over 30 to 60 | 1.3 | 4.0 |
| over 60 to 100 | 1.6 | 5.0 |
| over 100 to 150 | 2.0 | 6.0 |
| over 150 to 200 | 2.5 | 7.0 |
| over 200 to 300 | 3.0 | 8.0 |
Angularity
| Feature | Standard tolerance | Close tolerance, on request |
|---|---|---|
| Right angle (90°) between two faces | ± 1° 00′ | ± 0° 30′ |
| Any other included angle | ± 1° 30′ | ± 0° 45′ |
| Angle on a wall thinner than 3 mm | ± 2° 00′ | ± 1° 00′ |
Corner & fillet radius
| Adjoining wall thickness (mm) | Max sharp corner radius | Max internal fillet radius | Tolerance on a specified radius |
|---|---|---|---|
| up to 3.00 | 0.50 | 0.80 | ± 0.30 |
| over 3.00 to 6.00 | 0.80 | 1.20 | ± 0.40 |
| over 6.00 to 10.00 | 1.20 | 1.60 | ± 0.50 |
| over 10.00 | 1.60 | 2.40 | ± 0.60 |
Designing for extrusion: a truly sharp corner cannot be extruded — the die would break down within a few billets. A small radius at every corner and a generous fillet where walls meet extends die life, improves surface finish and holds dimensions better across a run.
Outside diameter & roundness
| Nominal outside diameter (mm) | Tolerance on diameter | Max out-of-roundness |
|---|---|---|
| up to 10.00 | ± 0.20 | 0.20 |
| over 10.00 to 18.00 | ± 0.25 | 0.25 |
| over 18.00 to 30.00 | ± 0.30 | 0.35 |
| over 30.00 to 50.00 | ± 0.40 | 0.50 |
| over 50.00 to 80.00 | ± 0.50 | 0.70 |
| over 80.00 to 120.00 | ± 0.65 | 0.95 |
| over 120.00 to 180.00 | ± 0.85 | 1.30 |
| over 180.00 to 250.00 | ± 1.15 | 1.75 |
Eccentricity of tube wall
| Wall thickness (mm) | Max wall variation in one cross-section |
|---|---|
| up to 3.00 | ± 10 % of nominal wall |
| over 3.00 to 6.00 | ± 10 % of nominal wall |
| over 6.00 | ± 12.5 % of nominal wall |
Chemical composition
Composition limits in weight %, to EN 573-3. A single figure is a maximum; a range is min – max. Remainder aluminium, others 0.05 each / 0.15 total.
6xxx series — our principal extrusion alloys
| Alloy | Si | Fe | Cu | Mn | Mg | Cr | Zn | Ti | Al |
|---|---|---|---|---|---|---|---|---|---|
| 6060 | 0.30–0.60 | 0.10–0.30 | 0.10 | 0.10 | 0.35–0.60 | 0.05 | 0.15 | 0.10 | Rem. |
| 6063 | 0.20–0.60 | 0.35 | 0.10 | 0.10 | 0.45–0.90 | 0.10 | 0.10 | 0.10 | Rem. |
| 6063A | 0.30–0.60 | 0.15–0.35 | 0.10 | 0.15 | 0.60–0.90 | 0.05 | 0.15 | 0.10 | Rem. |
| 6005 | 0.60–0.90 | 0.35 | 0.10 | 0.10 | 0.40–0.60 | 0.10 | 0.10 | 0.10 | Rem. |
| 6005A | 0.50–0.90 | 0.35 | 0.30 | 0.50 | 0.40–0.70 | 0.30 | 0.20 | 0.10 | Rem. |
| 6061 | 0.40–0.80 | 0.70 | 0.15–0.40 | 0.15 | 0.80–1.20 | 0.04–0.35 | 0.25 | 0.15 | Rem. |
| 6082 | 0.70–1.30 | 0.50 | 0.10 | 0.40–1.00 | 0.60–1.20 | 0.25 | 0.20 | 0.10 | Rem. |
| 6101 | 0.30–0.70 | 0.50 | 0.10 | 0.03 | 0.35–0.80 | 0.03 | 0.10 | — | Rem. |
| 6351 | 0.70–1.30 | 0.50 | 0.10 | 0.40–0.80 | 0.40–0.80 | — | 0.20 | 0.20 | Rem. |
| 6463 | 0.20–0.60 | 0.15 | 0.20 | 0.05 | 0.45–0.90 | — | 0.05 | — | Rem. |
Other series available to order
| Alloy | Si | Fe | Cu | Mn | Mg | Cr | Zn | Ti | Al |
|---|---|---|---|---|---|---|---|---|---|
| 1050A | 0.25 | 0.40 | 0.05 | 0.05 | 0.05 | — | 0.07 | 0.05 | 99.50 min |
| 1070A | 0.20 | 0.25 | 0.03 | 0.03 | 0.03 | — | 0.07 | 0.03 | 99.70 min |
| 1100 | 0.95 Si+Fe | 0.05–0.20 | 0.05 | — | — | 0.10 | — | 99.00 min | |
| 3003 | 0.60 | 0.70 | 0.05–0.20 | 1.00–1.50 | — | — | 0.10 | — | Rem. |
| 5052 | 0.25 | 0.40 | 0.10 | 0.10 | 2.20–2.80 | 0.15–0.35 | 0.10 | — | Rem. |
| 5083 | 0.40 | 0.40 | 0.10 | 0.40–1.00 | 4.00–4.90 | 0.05–0.25 | 0.25 | 0.15 | Rem. |
| 7075 | 0.40 | 0.50 | 1.20–2.00 | 0.30 | 2.10–2.90 | 0.18–0.28 | 5.10–6.10 | 0.20 | Rem. |
Typical mechanical properties (EN 755-2)
| Alloy & temper | UTS (MPa) | 0.2% Proof (MPa) | Elongation (%) | Hardness (BHN) |
|---|---|---|---|---|
| 6063 – T6 | 215 min | 170 min | 8 min | 73 typical |
| 6005 – T6 | 260 min | 215 min | 8 min | 85 typical |
| 6061 – T6 | 260 min | 240 min | 8 min | 95 typical |
| 6082 – T6 | 310 min | 260 min | 8 min | 95 min |
Section outside this envelope?
It can often still be produced. Send the drawing and our tool room will come back with feasibility, die cost and lead time.