In furnace construction, the steel framing member used to resist and hold the thrust of the refractory brickwork is called a:

Introduction / Context:
Large refractory structures such as furnaces require external steelwork to counteract the lateral thrusts caused by thermal expansion and arch action of brick linings. Knowing the correct terminology for these structural members is essential for design communication and maintenance.

Given Data / Assumptions:

• Refractory-lined furnace with significant internal pressure and thermal expansion.
• Need to prevent outward bulging and maintain geometry.
• Standard industrial vocabulary is used.

Concept / Approach:

A buckstay is a heavy steel member (often an I-beam) attached to the exterior of furnace walls to resist the thrust of the brickwork and maintain alignment. It works with tie rods, anchors, and buckstays at intervals to keep walls straight and prevent structural failure as the lining expands and contracts with temperature cycles.

Step-by-Step Solution:

Verification / Alternative check:

Furnace engineering texts and drawings label external vertical stiffeners as buckstays, often tied with horizontal members.

Why Other Options Are Wrong:

Breast wall: A wall portion near the furnace front. Armouring: Protective cladding, not the thrust-resisting frame. Baffle: Flow-directing internal plate, not a structural restraint.

Common Pitfalls:

Confusing internal flow-control components with external structural members.

Final Answer:

Buckstay