The Process
Design Guidelines
STANDARD PROFILE TOLERANCES
HOT EXTRUDED AND STRAIGHTENED – HOLLOW SECTION
A. EXTERNAL DIAMETER D
B. EXTERNAL DIAMETER D
C. DISPLACEMENT OF INTERNAL FORM
X: ± 1 MM
- Up to 50 mm: ± 0.5 mm
- Over 50 mm: ± 1%
- Thickness S: ± 10%
- (of the nominal thickness)
- Up to 50 mm: ± 0.5 mm
- Over 50 mm: ± 1%
- Thickness: ± 15%
- Thickness of fin e: ± 0.5 mm
- Width of fin b: ± 2 mm (or less on agreement)
- The tolerances of other hollow profile
shapes must be agreed after study.
For all other tolerances see table for solid
section profiles.
STANDARD PROFILE TOLERANCES
HOT EXTRUDED AND STRAIGHTENED – SOLID SECTION
A. DIMENSIONAL TOLERANCES OF THE
TRANSVERSE SECTION:
B.MINIMUM RADII:
C. ANGULAR TOLERANCES:
- Less than 25 mm ± 0.5 mm
- from 25 to 75 mm ± 0.8 mm
- from 75 to 100 mm ± 1.0 mm
- from 100 to 125 mm ± 1.2 mm
- over 125 mm ± 1.4 mm
- Ri = internal radius: minimum 4 mm
- Re = external radius: minimum 1.5 ± 0.5 mm
- Type 1 case ± 1°30’
- Type 2 case ± 0°30’
D.TRANSVERSE CURVATURE:
E.LONGITUDINAL CURVATURE:
F. WARP:
- X max = 1% of M
- (or less on agreement)
- X max. = 0,15% of L
- Max. deviation of 1mm per
meter or less (on agreement),
according to requirements.
G.DIMENSIONAL DIFFERENCES BETWEEN SYMMETRICAL PARTS:
H.DIMENSIONAL DIFFERENCES BETWEEN SYMMETRICAL PARTS:
I. LONGITUDINAL BAR TOLERANCES:
- Max difference between S and S’
half tolerance of point A
e.g. S = S’ = 28± 0.8 mm
max difference 0.8 mm
(hypothesis S = 27.6 S’ = 28.4)
- Max variation:half tolerance at point A
- e.g.: nominal values
M = M’ = 80 ± 1 mm
A = A’ = 40 ± 0.8 mm
S = S’ = 15 ± 0.5 mm - Example:
M = 79.5 M’ = 80.5
A = 39.4 A’ = 40.2
S = 14.75 S’ = 15.75
- a) from production ± 1 meter
- b) fixed: ± 2 mm; from 0+10mm (or on request)
- c) multiple: + 5 mm each multiple (or on request)
- d) commercial: from 3 meters to 7 meters