technical conditions from the manufacturer    


standard lengths:

diameter 3-6 mm - 1500 ± 20 mm
diameter 7-16 mm - 1500 ± 10 mm
diameter 18-30 mm - 1500 ± 30 mm

1500 ± 10 mm

1500+10 mm
-0 mm

non-circular assortment
1500 ± 20 mm

Non standard lengths: both shorter and longer lengths can be produced to suit special requirements. For example; depending on outside diameter and wall thickness, we can produce tubing up to 12 metres in length. Inquiries are most welcome.


Out-of-Roundness according to ISO 1101 depends on the outer diameter. The following limit values are fixed:

Ø <180 mm
smax 0,7 % of the outer diameter

Ø <10 mm
smax 1,0 % of the outer diameter

Ø <20 mm 
smax 1,0 % of the outer diameter
20 mm ≤ Ø ≤30 
smax 1,5 % of the outer diameter

wall thickness variance

The difference between the maximum and minimum wall thickness at arbitrary point of a tube may not exceed 12 percent of the wall nominal thickness.

tubes deflection acc. to ISO 1101:
outer diameter 4 to <6 mm
→ max. 4,0 mm/1500 mm
outer diameter ≥6 to <30 mm
→ max. 1,5 mm/1000 mm
outer diameter ≥30 to <100 mm
→ max. 2,0 mm/1400 mm
outer diameter ≥100 to ≤180 mm
→ max. 2,5 mm/1400 mm

Rods and capillaries are supplied with deflection of maximum 4 mm over 1500 mm of the product length.

Non-circular assortment is supplied as follows: tubes with deflection of max. 0,4% of nominal length as well as capillaries and rods with deflection of maximum 0,6% of nominal length.




Rods are not normally annealed, however, rods 18 to 30 mm diameter can be delivered annealed, if requested by the customer.

Profiles, and capillary tubes are not anneal.

stones and tails

The grain size is considered as corresponding to stones or tail size.

stones sizes:            per 1 kg  of glass
< 0,3 mm                   permitted
≥0.3-<1.0 mm           max. 2
≥1.0-≤2.0 mm           max. 1
>2.0 mm                   prohibited

tails sizes             per 1 kg of glass  
<0,3 mm                permitted
≥0.3-<1.0 mm       max. 4
≥ .0-≤3.0 mm        max. 2
>3.0 mm               prohibited


Bubbles length corresponds to the length of all bubbles ≥20 mm.
Permitted length of bubbles is 0,8 m/ 10 m of a tube. Bubbles <20 mm: 20 pcs/1 kg of glass.

Bubbles wider than 1 mm are prohibited in tubes with a diameter of Ø ≤100 mm
Bubbles wider than 2 mm are prohibited in tubes with a diameter of Ø >100 mm 

capillary bubble is a bubble drawn in the direction of the length of a product in the form of a capillary with a length greater than 2 mm.

4 ≤ Ø ≤  5 
5 < Ø ≤ 100 
100 < Ø ≤ 180

tube ends
not flame polsihed
flame polished
flame polsihed

front surfaces perpendicularity deviation

In flame polishing the ends, wall thickness may get enlarged by 0.1 mm.

Capillaries, rods and the profiles are not flame polished at the ends, with the exception of tubes fluted inside, which are flame polished at the ends.


Products are supplied in conveniently sized cartons, with sufficient protection against damage in transportation and storage.