Northern Manufacturing’s fabrication team is 160+ craftsmen, including 60+ AWS-certified welders working across 78 welding bays in Oak Harbor, Ohio. The company has fabricated metal here since 1951, 75 years and counting. A full-time Certified Welding Inspector (CWI), an in-house ASNT SNT-TC-1A Level III NDE technician, and weld procedures qualified per ASME BPVC Section IX and AWS D1.6 back every weld with documented, auditable qualification records. Here is what those qualifications mean when you’re evaluating a stainless steel fabrication partner.
Welding Qualifications
Welding stainless steel and specialty alloys is not the same job as welding carbon steel. Heat input windows are tighter, interpass temperatures matter more, and mistakes surface months later as corrosion failures or cracking in service. Our welding program exists to stop those failures before they start.
ASME BPVC Section IX Qualified Procedures and Personnel
Every weld procedure we run is qualified per ASME Boiler and Pressure Vessel Code, Section IX (2025 edition). Each procedure is proven through destructive testing of qualification coupons (tensile and bend testing at minimum) to confirm it produces sound welds in the specific material, thickness, and joint configuration your drawing calls out.
Qualified procedure coverage spans P8 austenitic stainless (304, 316, 309, 321), P10H duplex stainless (2205, 2507), P43 nickel alloys (Hastelloy C-276, Hastelloy C-22, Inconel), and P45 (AL-6XN), plus carbon steel, high-strength low-alloy, and qualified dissimilar-metal combinations for transition joints. The full P-number table lives on our stainless steel welding services page.
Welders are individually qualified under those procedures, and welder continuity logs are maintained current to the fabrication date. When your spec calls for Section IX compliance, the program is already running: no new procedure development, no welder qualification from scratch.
One scope note we make early and often: Northern holds the ASME U stamp (Certificate of Authorization #63199, shop manufacture of pressure vessels) and the ASME PP stamp (Certificate #63198, shop fabrication and assembly of pressure piping), both authorized May 2026. Section IX governs the welding qualification underneath both certificates. The certificates cover shop work at Oak Harbor only, not field code fabrication, and we do not hold the R stamp for code repairs or the S stamp for power boilers.
AWS D1.6 Structural Welding Code, Stainless Steel
Structural stainless fabrication runs to AWS D1.6, the structural welding code written specifically for stainless steel. It governs joint preparation, fit-up tolerances, welder qualification, and visual acceptance criteria. Our welders also hold qualifications under AWS D1.1 (structural steel) and AWS D1.2 (aluminum), and our resistance spot welder is qualified to AWS D17.2. With 60+ AWS-certified welders on the floor, Northern carries the certified depth to staff several large structural projects at the same time.
Welding Processes
The team runs nine qualified welding processes, each matched to the joint, the alloy, and the finish the application demands:
- GTAW (TIG): the primary process for stainless and specialty alloys. Full-penetration root passes, sanitary finishes, and any joint where weld integrity outweighs deposition rate.
- GMAW (MIG): production welding on stainless, carbon, and aluminum, with transfer mode selected for position and plate thickness.
- Fronius CMT: cold-metal-transfer GMAW for thin-gauge stainless and dissimilar joints where spatter and distortion are the failure modes.
- K-TIG (keyhole TIG): single-pass full penetration on stainless and duplex up to 1/2 inch thick without joint prep.
- Robotic GTAW and GMAW: cells programmed off CAD for bead-to-bead consistency on repeat-volume work. See robotic welding.
- SAW (submerged arc): high-deposition longitudinal seams on plate and rolled cylinders.
- FCAW (flux-cored): structural stainless and carbon work where throughput matters more than appearance.
- SMAW (stick): heavy-section structural and repair work on carbon and HSLA.
- Resistance spot welding: MySpot welder, AWS D17.2 qualified, for sheet assemblies.
Northern has also offered laser welding since 1998, and hybrid laser welding since 2015, for low-heat-input joining on thin and heat-sensitive material.
Inspection and Testing Qualifications
Certified Welding Inspector on Staff
We employ a full-time AWS Certified Welding Inspector. The CWI is not a consultant we call after something goes wrong; they are on the floor every day reviewing weld procedures, overseeing welder qualification, performing in-process inspections, and signing off final weld quality. In-house CWI capability means inspection is integrated into the production flow instead of waiting on a third party.
ASNT SNT-TC-1A Level III Nondestructive Examination
Northern’s NDE program is managed in-house by an ASNT Level III technician per SNT-TC-1A, the personnel qualification and certification standard from the American Society for Nondestructive Testing. The Level III maintains the written practice, trains and qualifies NDE personnel, and performs or supervises examinations. Visual (VT), liquid penetrant (PT), magnetic particle (MT), radiographic (RT), and ultrasonic (UT) testing all run in-house. For the measurement side of verification, laser trackers, laser projection, and weld scanning, see fabrication inspection and verification.
Positive Material Identification
Handheld XRF analyzers verify elemental composition on incoming material and on finished weldments. PMI confirms the 316L your drawing calls for is actually 316L, not 304 that was mislabeled at the mill. That check matters most on duplex grades and high-nickel alloys, where a material mix-up can mean premature failure in corrosive service.
Materials Expertise
Qualification on paper only matters if the team understands the metallurgy behind each grade. Three families make up most of our stainless work:
Austenitic stainless (304, 316, 309, 321, 347). The workhorses, run daily across every process in the shop. Heat input is controlled to keep the heat-affected zone below the sensitization range, and low-carbon L grades are specified where heavier sections demand them. More on austenitic fabrication.
Duplex stainless (2205, 2507, LDX 2101). Roughly twice the yield strength of 316L, and unforgiving on heat input. Our Section IX P10H procedures cap interpass temperature, specify matching filler (ER2209 for 2205, ER2594 for 2507), and require ferrite measurement on production weldments, not just qualification coupons. More on duplex fabrication.
High-nickel and specialty alloys (AL-6XN, Hastelloy C-276, Hastelloy C-22). Specified for the most corrosive environments, and fabricated under P43 and P45 procedures with low-heat-input GTAW and filler matched to base-metal chemistry. All of it runs inside our 40,000 sq ft stainless-only production space, where dedicated tooling and consumables keep carbon contamination off the work. More on specialty alloy fabrication.
Leadership and History
Northern Manufacturing was founded in 1951 in Oak Harbor, Ohio, and has fabricated metal continuously ever since. Tyson Smith and Haley Lonero have owned the company since 2019. Under their leadership, Northern expanded the indoor facility to 160,000 sq ft (completed January 2026) with four new overhead cranes and 90,000 sq ft of outdoor laydown, and invested in robotic welding, laser welding, and 5-axis laser cutting.
The principle behind that growth is simple: invest in the technology and people that make the customer’s product better. Stainless fabrication keeps getting more complex, and the shops that stand still fall behind.
Put These Qualifications to Work
If your project requires qualified welding procedures, documented NDE, and traceable materials, request a quote and tell us what you’re building. We’ll show you exactly which qualifications apply. You can also dig into our quality program, our certifications and compliance, or our welding capabilities.