Stitch Welder

Specifications, applications and operation

Specification breakdown. The Stitch Welder is offered in models SBSW-30-2Z, covering diameters from Φ100–Φ1000 mm, with a working length of 50–1000 mm, overlap 6 mm, handles material thicknesses of 0.4–1.0 mm, at a forming speed of 2 m/min, covering diameters from Φ20, max power 40 kW, and weighs approximately 850 kg, with overall dimensions of 2300×800×1300 mm (mainframe), requires 380V / 50Hz / 3PH.

Typical applications. Welding machines support a number of duct fabrication operations: longitudinal stitch welding of rectangular duct seams in heavy-gauge or stainless applications, spot welding of internal stiffeners and reinforcement, and seam welding of round duct fittings. Stainless duct fabricators and high-pressure industrial duct shops rely on welding equipment as their primary joining method, since SMACNA Seal Class A welded joints are required for many laboratory, hospital and clean-room exhaust systems.

How it works. Welding equipment for duct fabrication has to deliver consistent seam quality across a wide range of materials — galvanised steel, stainless 304/316, aluminium and aluminised steel — without operator intervention. The machine is configured for the target material, operators load the workpiece into the fixture, and the welding cycle runs automatically. Resistance, stitch and laser welding processes are used depending on the seam type and required strength.

Quality, certification and after-sales. Like every machine in the SBKJ catalogue, this unit is built to ISO 9001:2015 quality management standards and CE marked for European conformity. The factory in Jiangyin, Jiangsu has been operating since 1995 and SBKJ holds 60+ invention and utility patents in HVAC ductwork machinery design. Each machine ships with a 12-month warranty on mechanical and electrical components, lifetime spare-parts availability, and 3–7 days of on-site installation supervision and operator training by an SBKJ engineer. Remote support is available via WhatsApp and email, with engineer response within 12 hours and technical troubleshooting within 72 hours.

Where this fits in your workshop

Welding machines on a duct line cover three distinct jobs: longitudinal seam welding for spiral or rolled tube, circumferential welding for flange-to-duct attachment on heavy industrial duct, and stitch welding for stainless food-grade or chemical-resistant ductwork. The right machine depends on duct geometry, material and required leak class. SBKJ welding stations integrate with both the spiral duct line and the rectangular SBAL line as second-stage equipment, with fume-extraction provisions and operator screens included as standard.

Pre-purchase checklist

Use this list when you write the enquiry or when you compare two suppliers. Each line is something an SBKJ engineer will want clarified before quoting.

• Welding process — TIG for stainless, MIG for galvanised, laser for thin gauge
• Material thickness range and the gauges you need at full duty cycle
• Wire or rod feed compatibility with your local consumables supply
• Fume extraction connection for compliance with local OH&S rules
• Operator interface language and training requirements
• Power supply — some welders need a 415V dedicated feed

Operator and maintenance notes. The Stitch Welder is designed to be run by a single trained operator under normal conditions. Daily checks include lubrication of the forming rolls, inspection of the drive belts and chain tension, and a clean-down of the tool surfaces. Weekly checks add electrical cabinet inspection and a torque check on the main frame fasteners. SBKJ ships every machine with an English operator manual, a maintenance schedule and a recommended two-year spare parts kit. Operator training is included in the 7-day commissioning visit, and a refresher session can be booked at any time within the warranty period.