Stainless equipment for oven, dryer, heat-treat furnace, and glass-processing equipment builders: wall and roof panels, furnace nozzles and plenums, radiation shields, and precision thermal tooling in 304L, 309S, and alloy 625, welded with controlled heat input so the material keeps the scaling and oxidation resistance you specified it for. Built in a dedicated stainless-only production space in Oak Harbor, Ohio.
Northern Manufacturing fabricates custom stainless equipment for the companies that build industrial ovens, dryers, heat-treat furnaces, and glass-processing lines. Common work: oven wall, roof, and ceiling panels; furnace nozzles, plenums, and inner skins; radiation shields, shrouds, and recuperators; furnace trays and baskets; and the forming molds, rings, and fixtures for hot-process lines. Common grades: 304L for oven structure and trays, 309S for the radiant-heat sections that have to resist scaling, and alloy 625 where heat meets acid. All work runs through our 40,000 sq ft dedicated stainless-only production space in Oak Harbor, Ohio, where dedicated tooling keeps carbon contamination off high-alloy material.
60+ AWS-certified welders across 78 welding stations. ISO 9001:2015 certified (AVU Registrations). ASME BPVC Section IX qualified welding procedures for austenitic (P8) stainless, with heat input controlled to avoid sensitization in high-heat service. In-house pickling and passivation per ASTM A380/A967 in a 55-foot spray booth. CWI on staff.
Equipment We Build for Thermal Processing
Most of this work is for the OEMs that build the ovens, furnaces, and glass lines. What Northern regularly fabricates:
Oven Wall, Roof & Ceiling Panels
Sheet-and-frame stainless panel assemblies for continuous ovens and dryers, held flat across long spans so the sections seal at assembly.
Furnace Nozzles, Plenums & Inner Skins
Nozzles, plenums, inner skins, and hot-zone covers for high-temperature furnaces, built in 309S, the high-chromium grade that resists scaling under direct radiant heat.
Radiation Shields, Shrouds & Recuperators
Heat-treat furnace internals: radiation shields, shrouds, and recuperator sections built in grades matched to the furnace atmosphere and temperature.
Furnace Trays, Baskets & Fixtures
Load-bearing furnace trays, baskets, and handling fixtures that cycle hot and cold repeatedly, in 304 through the high-nickel grades for lines where heat meets corrosive chemistry.
Hot-Side Ductwork & Transitions
Duct, transitions, and exhaust sections for dryers and thermal systems, rolled and welded as full sections. See our stainless steel ductwork fabrication.
Thermal Process Tooling, Molds & Fixtures
Forming molds, rings, racks, and handling fixtures for glass-processing and other hot-process lines, built to the repeatable dimensional tolerance the tooling holds through thousands of heat cycles.
Stainless Grades for the Heat
Your spec calls the grade for the furnace atmosphere and the operating temperature, and we build to it; when the spec is open we will point you to a starting grade for the service, but the value we add is in the welding. Plain 304/304L covers oven structure and trays at moderate temperature. 309S carries the higher chromium and nickel that resists scaling and oxidation on the nozzles, plenums, and skins that see direct radiant heat. Alloy 625 goes where heat combines with acid attack, like handling hardware that rides hot acid lines. For the stabilized grades that resist sensitization in cyclic high-heat service (321 and 347) and the nickel-alloy metallurgy behind them, see our high-temperature alloy fabrication page.
| Grade | Why it is specified | Typical thermal application |
|---|---|---|
| 304 / 304L | Baseline austenitic for moderate-temperature oven structure | Oven wall, roof, and ceiling panels; furnace trays and baskets |
| 309S | High chromium and nickel for scaling and oxidation resistance under radiant heat | Furnace nozzles, plenums, inner skins, and hot-zone covers |
| Alloy 625 | Nickel alloy holding strength where heat meets acid attack | Handling hardware for hot acid lines and acid-condensate components |
| 321 / 347 | Titanium- and columbium-stabilized against sensitization after welding | Cyclic high-heat furnace components (see high-temperature alloy) |
Welding That Keeps the Grade Working
A thermal component lives or dies at the weld, because the furnace puts every joint through the temperatures that undo careless welding. Northern controls weld quality through ASME BPVC Section IX qualified procedures for austenitic (P8) stainless, with heat input controlled downward to keep the heat-affected zone out of the sensitization range.
On thin oven panels, distortion is managed before the first arc: controlled weld sequencing, back-stepping, and fixturing engineered for the part hold the panel flat so the sections seal square at assembly. On 309S and the nickel alloys, GTAW with stringer bead technique and interpass temperature limits protects the microstructure the grade depends on. For alloy 625 and the stabilized high-heat grades, the P43 nickel-alloy procedures and dissimilar-metal joints are detailed on our high-temperature alloy fabrication page.
Heat-Tint Removal and Passivation
Finishing is matched to where the part runs. Corrosion-critical and acid-service components get the full restoration; furnace internals that live in dry oxidizing service and form their own protective scale are finished to the level your spec calls out, not over-processed.
Post-Weld Pickling & Passivation
Post-weld pickling strips heat tint and embedded iron that would otherwise seed corrosion, then passivation restores the passive layer per ASTM A380 and A967. Our 55-foot spray booth treats entire assemblies in one pass, with no sectioning and no re-welding after treatment.
Free-Iron Verification
Where the spec requires it, free-iron verification per ASTM A380 confirms clean high-alloy surfaces before the part ships, so contamination is prevented by the stainless-only space first and then verified by test.
As-Welded or Mill Finish
For furnace internals running in dry, high-temperature oxidizing service, an as-welded or mill finish is often the right call. We finish to the drawing rather than adding cost the service does not need.
