Typical cold crushing strength (CCS) range for standard fireclay bricks is approximately how many kgf/cm²?

Introduction / Context:
Cold crushing strength (CCS) is a common quality metric for refractories, capturing the compressive load-bearing capacity at room temperature. For fireclay bricks, CCS falls in a characteristic range useful for quick specification checks.

Given Data / Assumptions:

• Standard fired fireclay bricks (not ultra-lightweight or ultra-dense grades).
• Measured at ambient temperature per common test methods.
• Typical values required, not extremes.

Concept / Approach:
Manufacturers and handbooks list fireclay CCS commonly between about 200 and 400 kgf/cm², depending on density, porosity, and firing regime. Very low-density insulating bricks will be far weaker; special high-density or high-alumina bodies can exceed this.

Step-by-Step Solution:
Recall the common specification band for general-purpose fireclay.Select the 200–400 kgf/cm² range.

Verification / Alternative check:
Vendor data sheets and standard references cluster fireclay CCS within this band for regular grades.

Why Other Options Are Wrong:
50–150: too low for typical dense fireclay.500–1000 or higher: more typical of dense high-alumina or special grades.

Common Pitfalls:
Confusing insulating firebrick values with dense fireclay brick values.

Final Answer:
200–400 kgf/cm²