99102124 - Tweco 9/16-18 Ballpoint Set Screw for MIG Guns

Technical Overview of the Tweco 9910-2124 Ballpoint Screw

The Tweco 9910-2124 is a specialized mechanical fastener designed specifically for the assembly and maintenance of Tweco MIG welding guns. This component is a 9/16-18 UNF-2A screw featuring a distinctive ballpoint tip. The primary engineering function of this screw is to provide a secure locking mechanism for the conductor tube or cable connection block within the gun handle, without compromising the structural integrity of the mating component.

In high-amperage welding applications, the connection between the power cable and the conductor tube must be mechanically rigid to maintain electrical conductivity and prevent resistive heating. However, the components being secured—often made of brass or copper alloys—are softer than the hardened steel of a standard set screw. A traditional flat or cup-point set screw would dig into these softer materials, causing galling, indentations, and deformation. This damage can make subsequent disassembly difficult or impossible and may ruin the conductor tube. The ballpoint design of the 9910-2124 solves this by incorporating a rolling or floating ball at the tip (or a rounded solid tip) that distributes the clamping force over a wider area and eliminates the rotational friction against the clamped surface during tightening.

The 9/16-18 UNF (Unified Fine) thread profile is chosen for this application to provide finer adjustment capabilities and higher tension per unit of torque compared to coarse threads. This ensures that the screw remains tight even under the thermal cycling and vibration inherent in industrial welding environments. The screw is manufactured from high-grade steel to withstand the torque required for a secure electrical and mechanical connection. It typically features a hex socket drive, allowing technicians to apply precise torque using standard hex keys. This part is critical for maintaining the alignment and electrical continuity of the MIG gun assembly, directly influencing the stability of the welding arc and the longevity of the gun's consumables.