Alumina (Al2O3) Content: 38% to 42%.
Refractoriness: SK34 (approx. 1750°C).
Bulk Density: 2.10 - 2.25 g/cm³.
Cold Crushing Strength (CCS): >= 25 MPa (Standard) / >= 35 MPa (High Density).
Thermal Expansion (at 1000°C): 0.5% - 0.6%.
Standard Dimensions: 230 x 114 x 65 mm (and custom shapes).
1. High temperature resistance
2. Good wear resistance
3. Weakly acidic at high temperatures
4. Strong erosion resistance
5. Good volume stability
6. Low prices
Used for lining blast furnaces, hot blast furnaces, electric furnace roofs, oxygen converters, reverberatory furnaces, and rotary kilns. They are also widely used as regenerative flat furnace checker bricks, plugs for pouring systems, and water mouth bricks, among other applications.
|
Item |
Index |
||||||||
|
Model |
N-1 |
N-2a |
N-2b |
N-3a |
N-3b |
N-4 |
N-5 |
N-6 |
|
|
Refractory temperature（℃≥） |
1750 |
1730 |
1730 |
1710 |
1710 |
1690 |
1670 |
1580 |
|
|
Bulk densityg/cm3 |
2.1 |
-- |
-- |
-- |
-- |
2.0 |
-- |
2.0 |
|
|
Softening temperature under load[0.2MPa*0.6%]≥ |
1400 |
1350 |
-- |
1320 |
-- |
1300 |
-- |
-- |
|
|
Reburning line change rate（%） |
1400℃*2h |
+0.1-0.4 |
+0.1-0.5 |
+0.1-0.5 |
-- |
-- |
-- |
-- |
-- |
|
1400℃*2h |
-- |
-- |
-- |
+0.2-0.5 |
+0.2-0.5 |
+0.2-0.5 |
+0.2-0.5 |
-- |
|
|
Apparent porosity（%≤） |
22 |
26 |
24 |
24 |
26 |
24 |
26 |
28 |
|
|
Normal temperature compressive strength（MPa≥） |
30.0 |
20.0 |
25.0 |
20.0 |
15.0 |
20.0 |
15.0 |
15.0 |
|
SK34 Fire Brick: The International Standard for Reliable High-Temperature Insulation
In the global refractory market, specifically within the Japanese Industrial Standards (JIS) framework, the SK34 firebrick stands as one of the most versatile and widely utilized fireclay bricks. Known for its optimal balance of thermal resistance and mechanical strength, the SK34 grade is the "gold standard" for medium-to-heavy duty industrial applications where temperatures consistently range between 1300°C and 1500°C.
Highland Refractory provides premium SK34 fire bricks manufactured with high-purity fireclay and professional-grade alumina. Our SK34 series is engineered to provide superior resistance to thermal shock and chemical erosion, making it the preferred choice for engineers in Southeast Asia, the Middle East, and beyond.
Understanding SK34 Technical Specifications
The "SK" designation refers to the Seger Cone equivalent, which indicates the brick's refractoriness. For an SK34 brick, the refractoriness is typically rated at 1750°C, though its continuous service temperature is generally recommended up to 1450°C-1500°C depending on the furnace environment.
Key Technical Parameters:
Alumina (Al2O3) Content: 38% to 42%.
Refractoriness: SK34 (approx. 1750°C).
Bulk Density: 2.10 - 2.25 g/cm³.
Cold Crushing Strength (CCS): >= 25 MPa (Standard) / >= 35 MPa (High Density).
Thermal Expansion (at 1000°C): 0.5% - 0.6%.
Standard Dimensions: 230 x 114 x 65 mm (and custom shapes).
SK32 vs. SK34 vs. SK38: Which Should You Choose?
Choosing the right SK grade is critical for both the longevity of your furnace and the cost-efficiency of your project.
SK32 (Low-Medium Duty): Contains approximately 30-35% Alumina. It is best suited for backup linings or environments where the temperature does not exceed 1250°C. It is the most economical choice.
SK34 (Medium-Heavy Duty): With 38-42% Alumina, it offers significantly better resistance to slag and thermal cycling than SK32. It is the ideal choice for "working linings" in most general-purpose kilns and domestic pizza ovens.
SK38 (High-Heavy Duty): Contains 45%+ Alumina and is designed for extreme environments like blast furnace stoves or high-heat glass regenerators where temperatures exceed 1550°C.
Core Applications for SK34 Firebricks
Because of its robust chemical and physical properties, Highland’s SK34 bricks are found in a wide array of thermal structures.
Industrial Boiler Linings
In biomass and coal-fired boilers, the combustion chamber faces constant abrasion from fuel particles. SK34 bricks provide the necessary hardness and thermal stability to ensure the boiler operates at peak efficiency with minimal maintenance.
Professional Pizza Ovens and Bakery Kilns
For the high-end culinary market, SK34 is the industry favorite. Its high thermal mass allows for excellent heat retention, while its food-safe mineral composition ensures a healthy cooking environment. It heats up evenly, preventing "cold spots" on the oven floor.
Incinerators and Flue Channels
SK34 is highly resistant to the acidic gases produced during waste incineration. Its low porosity helps prevent the penetration of corrosive elements into the brick structure, extending the life of the lining.
Ceramic and Glass Kilns
Used as the primary lining in hobbyist pottery kilns and as a secondary or backup lining in large-scale glass melting tanks.
Why Highland Refractory SK34 Bricks are Different
As an export-oriented manufacturer, Highland Refractory goes beyond standard production. We focus on the "Hidden Details" that matter to B2B buyers.
Dimensional Precision: We utilize automatic hydraulic presses to ensure that every SK34 brick has sharp edges and flat surfaces. This reduces mortar joint thickness, which is the #1 way to extend furnace life.
Controlled Firing Cycle: Our bricks are fired in high-capacity tunnel kilns with precise temperature control. This ensures a uniform mineral structure (Mullite phase) throughout the entire brick, not just the surface.
Lab-Verified Quality: Every shipment comes with a Certificate of Analysis (COA). We test for Al2O3 content, density, and cold crushing strength in our on-site laboratory.
Heavy-Duty Export Palletizing: We understand the rigors of sea freight. Our SK34 bricks are packed on reinforced pallets, corner-protected, and vacuum-sealed in moisture-proof plastic to ensure they arrive at your site in pristine condition.
Installation Tips for SK34 Refractory Linings
Use Compatible Mortar: For SK34 bricks, we recommend using a high-alumina air-setting mortar (like our Highland 3000F Cement). This ensures the bond is as strong as the brick itself.
Expansion Joints: Always allow for 0.5% linear thermal expansion. Failing to include expansion joints can lead to the bricks buckling or cracking as the furnace reaches peak heat.
Moisture Control: Keep the bricks dry before installation. If they absorb significant moisture, it can lead to steam-pressure spalling during the first firing.
Frequently Asked Questions (FAQ)
Q: Can SK34 bricks be used for a forge?
A: Yes, SK34 is excellent for blacksmithing forges. It can easily handle the temperatures required for heating steel, though for the "hot spot" where the burner hits directly, a higher alumina brick or coating might be used to prevent erosion.
Q: Is SK34 food safe for pizza ovens?
A: Absolutely. Our SK34 bricks are made from natural fireclay and alumina minerals. They do not contain any harmful chemical binders that could outgas during cooking.
Q: What is the difference between SK34 and a High Alumina brick?
A: SK34 is technically a "Super Duty Fireclay" brick. Bricks with Al2O3 content above 45-48% are generally classified as High Alumina. SK34 is the bridge between standard clay and high alumina.
Q: How many bricks are in a 20ft container?
A: For standard 230x114x65mm bricks, a 20ft container (subject to a 25-27 ton weight limit) can hold approximately 8,000 to 9,000 bricks.
Consult Highland Refractory for Your SK34 Requirements
Whether you are building a new industrial plant or repairing an existing kiln, Highland Refractory provides the JIS-standard quality and global logistics expertise you need. Our team of refractory engineers is ready to assist you with material selection and technical calculations.
Silicon carbide plates are mainly composed of silicon carbide (SiC) as the aggregate (with a content usually ≥ 80%).
