Typical Data STANDARD ASTM C 155 GRADES
Properties BNZ-20 BNZ-23 BNZ-23 HS BNZ-23A BNZ-26 BNZ-26-60 BNZ-28 BNZ-3000 BNZ-32
ASTM Classification 20/23 23 23 23 26 26 28 30 32
Temperature Use Limit
(Normal oxidizing atmosphere)		 °F
°C		 2300
1260		 2300
1260		 2300
1260		 2300
1260		 2600
1427		 2600
1427		 2800
1538		 3000
1649		 3200
1760
Density, Avg.
ASTM C 134		 lb/ft³
kg/m³
lb/BEq
kg/str.		 36
577
2.1
0.9		 37
593
2.2
1.0		 42
673
2.5
1.1		 33
529
1.93
0.86		 48
769
2.8
1.3		 50
801
2.9
1.3		 55
881
3.2
1.5		 65
1041
3.8
1.7		 75
1201
4.4
2.0
Modulus of Rupture
ASTM C 133		 lb/in²
MPa
kg/cm²		 95
0.7
6.7		 105
0.7
7.4		 140
1.0
9.9		 115
0.79
8		 200
1.4
14.1		 190
1.3
13.4		 220
1.5
15.5		 250
1.7
17.6		 300
2.1
21.1
Cold Crushing of Strength
ASTM C 133		 lb/in²
MPa
kg/cm²		 105
0.7
7.4		 125
0.9
8.8		 190
1.3
13.4		 145
1
10.2		 270
1.9
19.0		 290
2.0
20.4		 340
2.3
23.9		 440
3.0
31.0		 450
3.1
31.7
Permanent Linear Change %
    ASTM C 210
    24 hrs at soaking temp: °F (°C)
    2250 (1232) 0.0 0.0 0.0 0.0 – – – – –
    2350 (1290) – – – – – – – –
    2450 (1343) – – – – – – – –
    2550 (1399) – – – -0.4 -0.2 – – –
    2750 (1510) – – – – – -0.7 – –
    2800 (1538) – – – – – – – –
    2950 (1621) – – – – – – -0.7 –
    3150 (1732) – – – – – – – -0.4
Reversible Linear Thermal Expansion %
    at 2000°F (1093°C) 0.6 0.6 0.6 0.6 0.6 0.6 0.65 0.65 0.65
Hot Load Strength %
    ASTM C 16 deformation
    10 psi load for 11/2 hours: °F (°C)
    2000 (1093) 0 0 0 0 – – – – –
    2200 (1204) – – – 0.2 0.1 0.1 – –
    2400 (1316) – – – – – – 0.3 0.2
Thermal Conductivity Btu-in/ft², hr, °F
    ASTM C 182 (W/mk)
    Mean temperature, °F (°C)
      500 0.9 1.0 1.2 .92 1.6 1.8 2.3 2.8 3.9
      (260) 0.13 0.14 0.17 0.13 0.23 0.26 0.33 0.40 0.56
      1000 1.2 1.3 1.5 1.14 1.9 2.0 2.4 2.9 4.1
      (538) 0.17 0.19 0.22 0.16 0.27 0.29 0.35 0.42 0.59
      1500 1.5 1.6 1.7 1.39 2.2 2.1 2.6 3.1 4.2
      (816) 0.22 0.23 0.25  0.2 0.32 0.30 0.37 0.45 0.61
      2000 1.7 1.8 2.0 1.64 2.6 2.3 2.7 3.3 4.3
      (1093) 0.24 0.26 0.29 0.24 0.37 0.33 0.39 0.48 0.62
     To convert Btu-in/ft², hr, °F to Kcal-m², hr, °C,
multiply by 0.124.
Chemical Analysis
    Alumina – Al2O3 39.4 39.4 39.4 38.0 47.0 60.4 67.0 69.9 78.3
    Silica – SiO2 54.9 54.9 54.9 45 49.2 36.1 30.5 28.1 20.7
    Ferric Oxide – Fe2O3 0.7 0.7 0.7 0.3 0.6 0.4 0.3 0.3 0.2
    Titanium Oxide – TiO2 1.5 1.5 1.5 1.6 1.3 1.0 0.9 1.2 0.5
    Calcium Oxide – CaO 3.0 3.0 3.0 15 0.3 0.1 0.3 0.2 0.1
    Magnesium Oxide – MgO 0.1 0.1 0.1 0.1 0.1 0.2 0.0 0.1 0.1
    Alkalies, as Na2O & K2O 0.4 0.4 0.4 0.5 1.5 1.8 1.0 0.2 0.1