StarBlaze Prime 309Mo
AWS A5.4: E309Mo-16 | DIN EN ISO 3581-A: E 23 12 2 R 12
Rutile Coated | Mo-Alloyed | High Crack and Corrosion Resistance
StarBlaze Prime 309Mo is a rutile-coated stainless steel electrode alloyed with 23Cr, 12.5Ni, and 2.5Mo, designed for welding AISI 309 and 316 stainless steels as well as dissimilar joints involving mild steel. It serves effectively as a buffer layer prior to 316 cladding and performs well in applications demanding both corrosion and crack resistance. The arc is smooth and spatter-free, producing a clean bead with easy slag removal and minimal post-weld cleanup.
Available Packs
- Dimensions: 2.50 mm x 350 mm, 3.15 mm x 450 mm, 4.00 mm x 450 mm, 5.00 mm x 450 mm
- Pack Sizes: 2.5 Kg Pouch, 5 Kg Box
- Master Box: 20 Kg, 30 Kg, 40 Kg, Customisable packaging available on request
- Mo-enhanced weld metal for pitting and oxidation resistance
- Suitable for joining stainless to mild or low alloy steels
- Smooth weld finish with self-releasing slag
- Excellent crack resistance in maintenance and structural welding
- High mechanical properties: 650 N/mm² tensile strength, 35% elongation
- Arc stability supports consistent bead formation and operator comfort
- Petrochemical and refinery applications
- Food and dairy processing equipment
- Pressure vessel fabrication
- Chemical storage and transfer systems
- Stainless-to-carbon steel joining and buffer cladding jobs
- Shielded Metal Arc Welding (SMAW / MMA)
- Polarity: AC or DC
- Current range:
- 2.50 mm: 50–80 A
- 3.15 mm: 80–110 A
- 4.00 mm: 100–140 A
- 5.00 mm: 150–180 A
- Welding positions: 1G/PA, 2F/PB, 2G/PC, 3G/PF, 4G/PE
- Interpass temperature: < 200°C
- Keep electrodes dry; re-drying only if necessary at 250–300°C for 1 hour
- Offers good transition layer performance under cyclic loading
- Excellent for repairs, fabrication, or overlay in corrosive environments
- Versatile and operator-friendly for general stainless joining tasks
Product Details
Typical Weld Metal Chemical Composition (%)
| C | Si | Mn | Cr | Ni | Mo | S | P |
| 0.05 | 0.90 | 0.80 | 23.50 | 12.50 | 2.50 | 0.012 | 0.015 |
Typical Mechanical Properties (All Weld Metal)
| Tensile Strength
Rm (N/mm2) |
Elongation
A5 (%) |
Charpy Impact Value
(ISO-V J RT) |
| 650 | 35 | 65 |
Recommended Welding Parameters
| Diameter (mm) | Amperage Range (A) |
| 2.50 | 50-80 |
| 3.15 | 80-110 |
| 4.00 | 100-140 |
| 5.00 | 150-180 |
