SC12-4 - Smith SC12-4 Heavy Duty Acetylene Cutting Tip Size 4

Technical Overview of the Smith SC12-4 Acetylene Cutting Tip

The Smith SC12-4 is a heavy-duty replacement cutting tip designed specifically for use with oxy-acetylene fuel gas systems. Engineered for professional industrial applications, this Size 4 tip provides a substantial cutting capacity of up to 3 inches (76 mm), making it suitable for structural steel fabrication, heavy equipment repair, and demolition tasks. The tip belongs to the renowned SC12 series, known for its compatibility with Smith's DG200 and SC200 series cutting attachments, as well as all SC and DG series hand torches and machine torches.

Technically, the SC12-4 distinguishes itself with Smith's proprietary "Slip-in" design. Unlike traditional threaded tips that require wrench tightening—often leading to stripped threads or damaged seats—the SC12-4 seats firmly by hand. The tip utilizes a soft seat material and a recessed design that protects the seating surface from nicking and wear, ensuring a leak-proof seal over a long service life. The internal geometry features fully swaged high-quality copper construction, which creates mirror-smooth gas passages. This reduces turbulence in the gas flow, minimizes slag adherence to the tip face, and promotes stable, high-speed cutting.

Safety is a paramount feature of the SC12-4 architecture. It employs the "in-tip mix" principle, where oxygen and acetylene are mixed only within the tip itself, rather than in the torch head or tube. This design isolates the combustible mixture volume to the tip, drastically reducing the potential energy of a flashback and protecting the operator and the upstream equipment. With six preheat holes, the SC12-4 delivers a uniform preheat flame, essential for maintaining the ignition temperature on thicker plates and ensuring high-quality edge cuts in both manual and mechanized operations.