Electrowelded tubes and profiles are made of universal construction steel with S 235 JRG 2, S 275 JR and S235J2G3 quality, with regular hemical compositions and define mexanic-tehnikal characteristics.
| QUALITY STANDARS | |
|---|---|
| EN 10025 | DIN 17100 |
| TYPE OF STEEL | |
| S 235 JRG2 | R St 37-2 |
| S 235 JO | St37-3 U |
| S 235 J2G3 | St 37-3 N |
| S 275 JR | St 44-2 |
| S 275 Jo | St 44-3 U |
| S 275 J2G3 | St 44-3 N |
| S 335 JR | - |
| S335 JO | St 52-3 U |
| S 355 J2G3 | St 52-3 N |
Allowed tolerance
1.Weight
Tubes and profiles weight, can variate of the weight that is given in the tables, in margine beatween +10% and -8%, and it is calculated according the specific steel weight of 7,85 kg/dm3.
2.Form
Allowed tolerance for the straight, right angle, hollowness, and modulation is given in the table:
| CHARACTERISTIC | ALLOWED TOLERANCE |
|
|---|---|---|
| Tubes with rounded section | Tubes with square or rectangular section |
|
| Outside rate | ±1% of outside diametar but not least than ±0,5 мм | ±1% of the mesured sides but not least than ±0,5 мм |
| Wall thickness | ±10% with least ±0,2мм outside the welded place and angle of roundness |
|
| Right angle | - | 90° ±1° |
| Camber or hollownes | - | ±1% of sides lenght |
| Outside angle of roundness | - | most 3a (a=wall thickness) |
| Straight | 0,2% of total tubes lenght |
|
| Modulation | - | 2mm for the first 1000mm, + 0,5mm for every next 1000mm lenght |