1,We Manufacturing processes are primarily classified into four types:
1:Forging,
2:Casting,
3:Cutting,
4:Rolling.
2,We can manufacture in accordance with these standards.
Standards:
GB Series (Chinese Standards), JB Series (Machinery Standards), HG Series (Chemical Industry Standards), ASME B16.5 (American Standards), BS4504 (British Standards), DIN (German Standards), and JIS (Japanese Standards).
Internationally, there are two primary systems of pipe flange standards: the European system, represented by the German DIN standards (including those of the former Soviet Union), and the American system, represented by the US ANSI pipe flange standards. Other common standards include: the Chinese Ministry of Machinery Industry standards (JB series), the Ministry of Chemical Industry standards (HG series), the Chinese National Standard *GB/T 9112–9124-2010 Steel Pipe Flanges*, as well as US standards (ASME B16.5), British standards (BS4504), German standards (DIN), Japanese standards (JIS), and marine standards (CBM), among others.
The nominal pressure ratings for the PN series are designated by "PN" and comprise the following nine levels: PN2.5, PN6, PN10, PN16, PN25, PN40, PN63, PN100, and PN160.
The nominal pressure ratings for the Class series are designated by "Class" and comprise the following six levels: Class150, Class300, Class600, Class900, Class1500, and Class2500.
Flange Classification
1. **According to Chemical Industry Standards:** Flanges are classified as follows:
Plate Flat Welding Flange (PL), Necked Flat Welding Flange (SO), Necked Butt Welding Flange (WN), Integral Flange (IF), Socket Welding Flange (SW), Threaded Flange (Th), Butt Welding Ring Loose Flange (PJ/SE), Blind Flange (BL), Flat Welding Ring Loose Flange (PJ/PJ), and Lined Blind Flange (BL(s)).
2. **According to Petrochemical (SH) Industry Standards:** Flanges are classified as follows:
Threaded Flange (PL), Butt Welding Flange (WN), Flat Welding Flange (SO), Socket Welding Flange (SW), Loose Flange (LJ), and Blind Flange (no specific designation).
3. **According to Machinery (JB) Industry Standards:** Flanges are classified as follows:
Integral Flange, Butt Welding Flange, Plate Flat Welding Flange, Butt Welding Ring Plate Loose Flange, Flat Welding Ring Plate Loose Flange, Lap Joint Ring Plate Loose Flange, and Blind Flange.
4. **According to Connection Method/Type:** Flanges are classified as follows:
Plate Flat Welding Flange, Necked Flat Welding Flange, Necked Butt Welding Flange, Socket Welding Flange, Threaded Flange, Blind Flange, Necked Butt Welding Ring Loose Flange, Flat Welding Ring Loose Flange, Ring-Type Joint (RTJ) Flange and Blind Flange, Large-Diameter Plate Flange, Large-Diameter High-Neck Flange, Figure-8 Blind Plate, Butt Welding Ring Loose Flange, etc.
5. **According to the Component Being Connected:** Flanges can be classified into Vessel Flanges and Pipe Flanges.
6. **According to Structural Type:** Flanges include Integral Flanges, Threaded Flanges, Flat Welding Flanges, Butt Welding Flanges, Lap Joint (Loose/Swivel) Flanges, and Blind Flanges.
A flange—also referred to as a flange plate or rim—is a component used to connect shafts to one another, or, more commonly, to join the ends of pipes. Flanges are also utilized at the inlet and outlet ports of equipment to facilitate connections between two devices—for instance, the flange on a speed reducer. A "flange connection" or "flanged joint" refers to a detachable joint assembly comprising three interconnected elements—a flange, a gasket, and bolts—that together form a sealed structural unit. In the context of piping systems, a "pipe flange" specifically denotes a flange used for plumbing within the installation; when applied to equipment, it refers to the inlet or outlet flange of that specific device. Flanges feature a series of holes through which bolts are inserted to securely fasten the two flanges together, while a gasket placed between the flanges ensures a leak-proof seal. Flanges are broadly categorized into three types: threaded (screw-in) flanges, welded flanges, and clamp-type flanges. Flanges are invariably used in pairs; threaded flanges are suitable for low-pressure piping applications, whereas welded flanges are required for systems operating at pressures exceeding 4 kilograms per square centimeter. A sealing gasket is inserted between the two flange plates, which are then firmly secured using bolts. The thickness of a flange—as well as the specifications of the bolts used to fasten it—vary depending on the specific pressure rating required for the application. When connecting equipment such as water pumps or valves to piping systems, the corresponding connection points on these devices are often manufactured in the shape of a matching flange; this method of attachment is also referred to as a "flange connection." Generally, any connecting component that utilizes bolts to join and seal the perimeters of two flat surfaces—such as the joints in ventilation ducts—is termed a "flange"; such components may collectively be classified as "flange-type parts." However, since such a connection often constitutes merely a *portion* of a larger device—for instance, the interface between a flange and a water pump—it would be inappropriate to classify the entire water pump itself as a "flange-type part." Conversely, smaller components—such as valves—that feature such flanged interfaces may indeed be appropriately categorized as "flange-type parts."
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AISI 4161 Steel Flange Product Information
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AISI 4161 Steel Flange Synonyms
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AISI 4161 Steel Product Information
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# **AISI 4161 Steel Product Specification**
## **1. Product Overview & Classification**
**AISI 4161** is a **high-carbon, high-manganese chromium-molybdenum alloy steel** that represents a specialized, high-hardenability variant within the 41xx series. Distinguished by its elevated manganese content (1.00-1.30%) compared to standard 41xx grades, 4161 is engineered for applications requiring **exceptional hardenability, maximum achievable strength, and superior wear resistance** in large cross-sections or demanding service conditions.
**Key Distinguishing Features:**
- **High Manganese (1.00-1.30%):** Significantly higher than standard 41xx grades (typically 0.60-1.00%)
- **High Carbon (0.56-0.64%):** Approaches the boundary between alloy steel and tool steel
- **Specialized Application:** Designed for extreme hardenability requirements
- **Manufacturing Status:** Historical SAE/AISI grade; less commonly produced than mainstream grades
## **2. International Standards & Designations**
| Region/Standard | Designation | Status & Notes |
|-----------------|-------------|----------------|
| **United States** | AISI 4161, SAE 4161 | Historical SAE specification; not in current ASTM standards |
| **UNS Designation** | G41610 | Assigned but rarely used |
| **Europe** | No direct equivalent | Closest: Special 50CrMo6 with Mn adjustment |
| **Japan** | No direct equivalent | Closest: Special SCM440/445 high-Mn variant |
| **China** | No direct equivalent | Similar to 55CrMo with Mn modification |
| **ISO** | No direct equivalent | - |
| **Industry Status** | Specialty/Proprietary grade | Often supplied to customer specifications |
**Note:** Due to its specialized nature, 4161 is typically produced to customer-specific requirements rather than standardized specifications.
## **3. Chemical Composition (Weight %)**
*Defined by historical SAE specifications; may vary by manufacturer*
| Element | Composition Range (%) | Typical Aim (%) | Metallurgical Significance |
|---------|----------------------|-----------------|---------------------------|
| **Carbon (C)** | 0.56 - 0.64 | 0.60 | Very high carbon; provides maximum strength and hardenability |
| **Manganese (Mn)** | 1.00 - 1.30 | 1.15 | **Key feature:** Exceptional hardenability enhancement |
| **Phosphorus (P)** | ≤ 0.035 | 0.020 | Controlled low level for toughness preservation |
| **Sulfur (S)** | ≤ 0.040 | 0.025 | Controlled for machinability improvement |
| **Silicon (Si)** | 0.15 - 0.35 | 0.25 | Standard range; deoxidizer and strengthener |
| **Chromium (Cr)** | 0.70 - 0.90 | 0.80 | Slightly lower than standard 41xx; balanced with high Mn |
| **Molybdenum (Mo)** | 0.15 - 0.25 | 0.20 | Standard range; prevents temper embrittlement |
| **Nickel (Ni)** *optional* | ≤ 0.25 (residual) | 0.10 | May be present as residual element |
**Key Compositional Characteristics:**
1. **Carbon-Manganese Synergy:** High Mn allows full exploitation of high carbon content
2. **Modified Balance:** Lower Cr than typical 41xx to accommodate high Mn
3. **Hardenability Focus:** Chemistry optimized for maximum hardenability
4. **Tool Steel Proximity:** Carbon level approaches that of many tool steels
## **4. Hardenability Characteristics**
*Exceptional hardenability is the defining feature of 4161*
### **Jominy End-Quench Data (Estimated)**
| Distance from Quenched End | As-Quenched Hardness (HRC) | Characteristics |
|----------------------------|----------------------------|-----------------|
| **J₁ (Surface)** | 62 - 65 | Extremely high surface hardness |
| **J₄ (1/4" depth)** | 58 - 62 | Maintains very high hardness |
| **J₈ (1/2" depth)** | 54 - 58 | Excellent depth of hardening |
| **J₁₂ (3/4" depth)** | 50 - 54 | Superior to most alloy steels |
| **J₂₀ (1.25" depth)** | 44 - 48 | Exceptional deep hardening |
### **Hardenability Performance Metrics**
- **Ideal Critical Diameter (Dᵢ):** 150-180 mm (6-7 inches) in oil
- **95% Martensite Diameter (D₉₅):** 125-150 mm (5-6 inches) in oil
- **Grossmann Hardenability Factor:** 7.0-8.0 (Exceptional)
- **Quench Severity Required:** Moderate (H=0.30-0.40 sufficient)
- **Maximum Practical Diameter (Full Hard):** 200 mm (8 inches) with proper quench
## **5. Physical Properties**
*Typical values; vary with heat treatment condition*
| Property | Value Range | Conditions/Notes |
|----------|-------------|------------------|
| **Density** | 7.85 g/cm³ (0.284 lb/in³) | At 20°C |
| **Melting Range** | 1380-1475°C (2515-2685°F) | Lower due to high carbon and manganese |
| **Modulus of Elasticity (E)** | 205-210 GPa | At 20°C |
| **Shear Modulus (G)** | 80-82 GPa | At 20°C |
| **Poisson's Ratio (ν)** | 0.29 | At 20°C |
| **Thermal Conductivity** | 38.5-40.5 W/m·K | At 100°C (lower due to high alloy content) |
| **Specific Heat Capacity** | 460-475 J/kg·K | At 20°C |
| **Coefficient of Thermal Expansion** | 12.3 × 10⁻⁶ /K | 20-100°C range |
| **Electrical Resistivity** | 0.27-0.30 µΩ·m | At 20°C (higher due to alloy content) |
| **Magnetic Properties** | Ferromagnetic | - |
## **6. Mechanical Properties by Condition**
### **Annealed/Normalized Condition**
| Property | Value Range | Characteristics |
|----------|-------------|-----------------|
| **Hardness** | 248-302 HB | Higher than standard 41xx due to high carbon |
| **Tensile Strength** | 895-1035 MPa | Strong normalized properties |
| **Yield Strength** | 620-795 MPa | - |
| **Elongation** | 12-18% | Limited due to high carbon |
| **Reduction of Area** | 35-45% | - |
| **Machinability** | 35-40% of B1112 | Difficult due to high hardness |
### **Quenched & Tempered Performance**
*After oil quenching from 815-830°C (1500-1525°F)*
| Tempering Temperature | Hardness (HRC) | Tensile Strength | Charpy Impact (20°C) | Application Focus |
|-----------------------|----------------|------------------|----------------------|-------------------|
| **175°C (350°F)** | 60-63 | 1930-2070 MPa | 7-14 J | Maximum wear resistance |
| **205°C (400°F)** | 58-61 | 1860-2000 MPa | 10-20 J | High wear applications |
| **315°C (600°F)** | 54-57 | 1725-1860 MPa | 14-27 J | High strength, some toughness |
| **425°C (800°F)** | 48-52 | 1520-1655 MPa | 20-34 J | General high-strength |
| **540°C (1000°F)** | 41-45 | 1310-1450 MPa | 27-41 J | Strength-toughness balance |
| **595°C (1100°F)** | 35-39 | 1170-1310 MPa | 34-48 J | Improved toughness |
## **7. Heat Treatment Guidelines**
### **Critical Heat Treatment Considerations**
```
SPECIAL CONSIDERATIONS FOR 4161:
1. LOWER AUSTENITIZING TEMPERATURE: 800-825°C (1475-1520°F)
- Due to high carbon and manganese
- Prevents excessive grain growth
- Reduces risk of quench cracking
2. CONTROLLED QUENCHING:
- Oil quench preferred (fast oil, 50-60°C)
- Polymer quenchants may be used for complex shapes
- Water or brine quench NOT recommended (extreme cracking risk)
3. TEMPERING REQUIREMENTS:
- Mandatory: Never use in as-quenched condition
- Minimum tempering: 175°C (350°F) for stress relief
- Double tempering strongly recommended
```
### **Recommended Heat Treatment Cycle**
```
Step 1: PREHEAT
Temperature: 650-700°C (1200-1290°F)
Time: 45-60 minutes per inch of thickness
Purpose: Minimize thermal shock and distortion
Step 2: AUSTENITIZE
Temperature: 810-825°C (1490-1520°F)
Time: 30-45 minutes per inch
Atmosphere: Protective (endothermic gas)
Control: ±5°C accuracy critical
Step 3: QUENCH
Medium: Fast oil (ISO VG 46-68)
Temperature: 50-60°C, vigorous agitation
Delay: <3 seconds from furnace to quench
Step 4: TEMPER
Temperature: According to application requirements
Time: 2+ hours per inch, minimum 2 hours
Cycle: Double temper recommended (2nd temper 15-20°C lower)
Step 5: STRESS RELIEF (Optional)
Temperature: 150-200°C (300-400°F)
Time: 2-4 hours
Purpose: For precision components after machining
```
## **8. Microstructural Characteristics**
### **Typical Microstructures**
**Annealed/Normalized Condition:**
- Fine pearlite with some spheroidized carbides
- Possible cementite networks at grain boundaries (if poorly annealed)
- Grain size: ASTM 5-7 typically
**Quenched & Tempered Condition:**
- Tempered martensite with fine alloy carbides
- Carbide types: M₃C, M₇C₃, M₂₃C₆ (depending on tempering)
- Possible retained austenite if improperly quenched
- Grain size: ASTM 7-9 with proper heat treatment
### **Special Metallurgical Considerations**
1. **Manganese Effect:** Delays pearlite transformation, promotes martensite
2. **Carbon Solubility:** High carbon may lead to carbide networks if improperly processed
3. **Hardenability:** Extreme hardenability can lead to quench cracking if not controlled
4. **Temper Resistance:** Good resistance to overtempering due to alloy content
## **9. Manufacturing & Processing Characteristics**
### **Machinability**
- **Annealed Condition:** 35-40% of B1112 (Very Difficult)
- **Normalized Condition:** 30-35% of B1112 (Extremely Difficult)
- **Hardened Condition:** 15-20% of B1112 (Grinding preferred)
- **Tool Requirements:** Premium carbide or CBN tools essential
- **Coolant:** High-pressure coolant mandatory
- **Chip Formation:** Short, segmented chips; high cutting forces
### **Welding Characteristics**
- **Rating:** Extremely Poor (Generally Not Recommended)
- **If Required:** Must be in fully annealed condition
- **Preheat:** 300-400°C (575-750°F) minimum
- **Post-Weld:** Full reheat treatment cycle required
- **Filler Metals:** Austenitic stainless or nickel-based alloys may be used
- **Applications:** Generally avoided; consider mechanical joining instead
### **Grindability**
- **Rating:** Fair to Good with proper technique
- **Wheel Selection:** Aluminum oxide A36-46, hardness J-K, or CBN
- **Coolant:** Essential to prevent burns
- **Risk:** High susceptibility to grinding cracks due to high hardness potential
## **10. Product Applications**
*Due to its specialized nature, 4161 is used in specific, demanding applications*
### **Extreme Wear Applications**
- **Crusher roll shells** for hard rock processing
- **Grinding mill liners** for mineral processing
- **Pulverizer hammers** for coal and ore
- **Shot blast machine blades** and **components**
- **Slurry pump wear parts** for abrasive slurries
### **Large Section Components**
- **Backup rolls** for steel rolling mills (200-500 mm diameter)
- **Large gear blanks** requiring guaranteed through-hardening
- **Forging die blocks** for heavy forging
- **Extruder screws** for highly abrasive materials
- **Mandrels** for large diameter tube production
### **Specialized Industrial Applications**
- **Knives** for cutting abrasive materials
- **Shear blades** for metal cutting
- **Die inserts** for high-wear forming operations
- **Anvil blocks** for impact applications
- **Wear plates** for heavy equipment
### **Historical & Niche Applications**
- **Military vehicle components** requiring extreme hardness
- **Railroad rail ends** for special track sections
- **Mining shovel teeth** for hardest rock conditions
- **Oil drilling tools** for hardest formations
- **Special cutting tools** where tool steel is not suitable
## **11. Comparison with Similar Grades**
### **vs. AISI 4150**
| Parameter | AISI 4161 | AISI 4150 | Advantage |
|-----------|-----------|-----------|-----------|
| **Carbon** | 0.56-0.64% | 0.48-0.53% | 4161: Higher strength potential |
| **Manganese** | 1.00-1.30% | 0.75-1.00% | 4161: Superior hardenability |
| **Max Hardness** | 62-65 HRC | 58-62 HRC | 4161: Higher wear resistance |
| **Hardenability** | Exceptional | Excellent | 4161: Larger sections possible |
| **Toughness** | Lower at same hardness | Higher | 4150: Better for impact |
| **Availability** | Special order | Readily available | 4150: Better supply |
### **vs. Tool Steels (e.g., AISI S7, H13)**
| Aspect | AISI 4161 | Tool Steels | Consideration |
|--------|-----------|-------------|---------------|
| **Carbon Range** | 0.56-0.64% | 0.35-1.00% | Overlap exists |
| **Primary Purpose** | Structural/wear | Tooling/molding | Different focus |
| **Toughness** | Lower generally | Often higher | Tool steels better for impact |
| **Hot Hardness** | Moderate | Often superior | Tool steels better for hot work |
| **Cost** | Lower | Higher | 4161 more economical |
| **Best For** | Large structural wear parts | Tools, dies, molds | Different applications |
## **12. Quality & Testing Requirements**
### **Standard Testing**
1. **Chemical Analysis:** Full spectrographic analysis essential
2. **Hardness Testing:** Multiple locations and depths
3. **Tensile Testing:** At room and elevated temperatures if needed
4. **Charpy Impact:** Multiple temperatures for critical applications
5. **Microstructure:** Full examination for carbide distribution
### **Enhanced Testing for Critical Applications**
- **Ultrasonic Testing:** For internal soundness in large sections
- **Magnetic Particle Inspection:** For surface defects
- **Fracture Toughness Testing:** K₁c or J₁c testing
- **Hardenability Testing:** Jominy tests for certification
- **Residual Stress Analysis:** For distortion-critical components
## **13. Design & Engineering Considerations**
### **Advantages of AISI 4161**
1. **Exceptional Hardenability:** Through-hardens extremely large sections
2. **Maximum Wear Resistance:** Highest achievable hardness in 41xx family
3. **Good Strength:** Very high tensile and yield strength potential
4. **Cost-Effective:** More economical than tool steels for some applications
5. **Proven Performance:** Historical use in extreme conditions
### **Limitations & Challenges**
1. **Poor Toughness:** Low impact resistance compared to lower-carbon grades
2. **Machining Difficulty:** Very difficult to machine in all conditions
3. **Weldability:** Essentially non-weldable in practical terms
4. **Quench Cracking Risk:** High due to extreme hardenability
5. **Notch Sensitivity:** Very sensitive to stress concentrators
### **Design Recommendations**
- **Avoid Sharp Corners:** Minimum radius 5 mm (0.20 in)
- **Gradual Transitions:** Taper ratios of 1:4 or greater
- **Surface Finish:** Critical areas should be ground to 1.6 µm Ra or better
- **Stress Relief:** Always stress relieve after rough machining
- **NDT Requirements:** Full non-destructive testing recommended
## **14. Economic & Supply Considerations**
### **Market Status**
- **Availability:** Special order only; not stock material
- **Lead Times:** 12-20 weeks typically
- **Minimum Order:** 5,000-10,000 lbs for melt
- **Cost Premium:** 1.5-2.0× standard 4140 cost
- **Manufacturers:** Limited to specialty steel producers
### **Total Cost Analysis**
1. **Material Cost:** High due to specialized production
2. **Processing Cost:** High due to machining difficulty
3. **Heat Treatment Cost:** Requires specialized facilities
4. **Performance Benefits:** May justify cost in extreme applications
5. **Life Cycle Cost:** Can be favorable if replacement costs are high
## **15. Technical Specifications Summary**
### **Material Selection Guidelines**
```
Consider AISI 4161 when:
- Component diameter >150 mm (6 inches) requires full hardening
- Wear resistance is primary requirement
- Cost prohibits tool steels but performance exceeds 4150
- Historical specification or replacement part
- Extreme service conditions justify specialized material
Consider alternatives when:
- Impact toughness >40 J is required
- Welding is needed in fabrication
- Machining cost is prohibitive
- Corrosion resistance is needed
- Standard materials can meet requirements
```
### **Future Outlook**
- **Trend:** Decreasing use due to availability and processing challenges
- **Alternatives:** Modern steelmaking allows other grades to achieve similar properties
- **Niche Role:** Remains relevant for specific replacement parts and extreme applications
- **Development:** May be replaced by proprietary grades with better balance of properties
---
## **Summary: Application Decision Framework**
### **Ideal Applications for AISI 4161**
1. **Replacement Parts:** For existing equipment originally designed with 4161
2. **Extreme Wear:** Components subject to severe abrasive wear
3. **Large Sections:** Diameters >150 mm requiring guaranteed through-hardening
4. **Specialized Machinery:** Where historical specifications must be maintained
5. **Cost-Sensitive Extreme Applications:** Where tool steels are too expensive
### **Practical Implementation Considerations**
- **Heat Treatment Facilities:** Requires sophisticated, controlled heat treatment
- **Machining Capability:** Needs premium tooling and expertise
- **Design Adaptation:** Must accommodate material limitations
- **Testing Regimen:** Comprehensive testing typically required
- **Supplier Qualification:** Must identify capable specialty steel producers
### **Value Proposition**
AISI 4161 offers **maximum achievable hardenability and wear resistance within the 41xx alloy steel family**. Its use is justified when:
1. No other standard alloy steel provides sufficient hardenability
2. Tool steels are cost-prohibitive for the application
3. Historical compatibility is required
4. The performance premium justifies the material and processing costs
---
**Final Recommendation:** AISI 4161 represents a highly specialized material for extreme applications. Its selection should be based on specific, justified requirements that cannot be met by more readily available grades. For new designs, consider whether modern alternatives (modified 4140/4150, proprietary grades, or selected tool steels) might provide better overall performance or cost-effectiveness.
**Historical Note:** As a historical SAE grade, 4161 represents an era when extreme hardenability was achieved through high manganese additions. Modern steelmaking often achieves similar results through different alloying approaches or processing methods.
---
**Disclaimer:** This product specification describes a historical/specialty grade that may not be readily available from all suppliers. Actual properties and availability should be confirmed with specialty steel producers. For new designs, consultation with materials engineering specialists is strongly recommended to evaluate whether more modern alternatives might better meet requirements. The information presented is based on historical data and typical values; actual properties may vary significantly based on specific manufacturing processes.
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AISI 4161 Steel Specification
Dimensions
Size：
Diameter 20-1000 mm Length <4055 mm
Size:We can customized as required
Standard：
Per your request or drawing
We can customized as required
Properties（Theoretical）
Chemical Composition
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AISI 4161 Steel Properties
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Applications of AISI 4161 Steel Flange
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Chemical Identifiers AISI 4161 Steel Flange
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Packing of AISI 4161 Steel Flange
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Standard Packing:
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Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and Steel Flange drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 526 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition
