When making an exothermic weld, no sleeve is required for wires _______.

In the context of making an exothermic weld, the requirement for a sleeve is determined by the size of the welding wires being used. Wires that are No. 6 AWG and larger are robust enough to withstand the heat and mechanical requirements of the welding process without the need for a protective sleeve.

Using a sleeve helps to contain and manage the heat and material flow during the welding process, but larger wires like No. 6 AWG can effectively manage these parameters on their own due to their increased cross-sectional area and strength. This allows for a more efficient welding process and enhances the potential for a stronger, more durable joint.

Smaller wire sizes would necessitate a sleeve to ensure stability and proper heat management during the exothermic reaction. As a result, wires smaller than No. 6 AWG may require additional support from sleeves, while those No. 6 AWG and larger do not, making the answer both practical and aligned with standard practices in exothermic welding.