CHEMGLASS CG-8734-29 Stopper Hollow Glass 29/35

( Brand: Chemglass ), ( Manufacturer Part Number: CG-8734-29 ), ( Part Type: Stopper ), ( Country Of Origin: United States ), ( Unit Type: Unit ), ( Intended Use/discipline: Biological Laboratory, Medical Laboratory, Microbiological Laboratory )

Review CHEMGLASS Stopper 29/35 Hollow Glass

The **Chemglass CG-8734-29 Hollow Glass Stopper (29/35 Joint)** is a precision-engineered laboratory component designed for seamless integration into ground-glass joint systems, offering both functionality and versatility for a wide range of chemical and analytical applications. Crafted from high-quality borosilicate glass (Type I, conforming to ASTM E438 and USP Class A standards), this stopper is engineered to withstand extreme temperatures, aggressive solvents, and repeated autoclaving cycles, making it an ideal choice for demanding laboratory environments. The **29/35 joint** designation ensures a secure, leak-proof fit with standard laboratory glassware, including flasks, round-bottom bottles, and reaction vessels, while the **hollow design** provides enhanced aeration and pressure equalization, reducing the risk of vacuum lock or explosive decompression during processes like distillation, filtration, or solvent evaporation. The smooth, polished glass surface minimizes residue buildup and facilitates easy cleaning, while the durable construction resists thermal shock, ensuring reliability even when transitioning between cryogenic and high-temperature conditions. Whether used in routine synthesis, chromatographic separations, or specialized analytical techniques, this stopper delivers consistent performance, contributing to the precision and efficiency of laboratory workflows. Its compatibility with standard laboratory glassware and adherence to rigorous quality standards make it a trusted component for researchers, chemists, and technicians seeking dependable, long-lasting glassware solutions.

**Pros and Cons of buying a Chemglass CG-8734-29 Stopper (29/35 Hollow Glass)**

### **Pros**

1. **High-Quality Construction** Chemglass is a well-established manufacturer known for producing durable, precision-engineered laboratory glassware. The CG-8734-29 stopper is designed to fit securely in 29/35 standard ground glass joints, ensuring a tight seal for experiments requiring minimal contamination or leakage.

2. **Hollow Design for Improved Functionality** The hollow interior allows for better gas exchange or venting, which is useful in applications like distillation, extraction, or reactions where pressure buildup needs to be managed. It can also serve as a conduit for introducing or removing gases.

3. **Compatibility with Standard Laboratory Equipment** The 29/35 joint size is widely used in laboratory glassware, making this stopper interchangeable with other Chemglass or third-party products. This ensures versatility in setups.

4. **Chemical Resistance** Made from borosilicate glass (likely Type 1 or similar), the stopper is resistant to most acids, bases, and organic solvents, making it suitable for a broad range of chemical applications.

5. **Easy to Clean and Sterilize** Glass is non-porous and can be cleaned thoroughly with solvents or sterilized with heat or autoclaving, reducing the risk of cross-contamination in laboratory settings.

6. **Durability** Chemglass products are known for their longevity, even with frequent use. The stopper is less likely to degrade or warp over time compared to plastic alternatives.

7. **Precision Fit** The ground glass joint ensures a consistent, leak-proof seal when properly lubricated, which is critical for experiments requiring controlled conditions.

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### **Cons**

1. **Fragility** Glass is brittle and can shatter if dropped or subjected to thermal shock (e.g., rapid temperature changes). This makes handling more cautious compared to plastic or metal stoppers.

2. **Maintenance Requirements** Ground glass joints require periodic cleaning and lubrication (e.g., with stopcock grease or silicone grease) to maintain a proper seal. Neglecting this can lead to leaks or damage.

3. **Limited Reusability Over Time** Even with care, the ground glass surface can wear down with repeated use, eventually requiring replacement. This adds to long-term costs.

4. **Weight** Glass stoppers are heavier than plastic alternatives, which may be less convenient for frequent adjustments or in applications where portability is a concern.

5. **Cost** High-quality glassware from Chemglass is more expensive upfront compared to some plastic or disposable options. However, this is often justified by durability and performance.

6. **Potential for Contamination** If not cleaned thoroughly, ground glass joints can harbor residues from previous experiments, which may interfere with new procedures.

7. **Not Ideal for High-Pressure Applications** While suitable for most laboratory uses, hollow glass stoppers may not be appropriate for high-pressure systems where specialized seals (e.g., metal or PTFE) are required.

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### **Conclusion**

The **Chemglass CG-8734-29 hollow glass stopper** is a reliable, high-performance component for laboratories requiring precise, leak-proof seals in standard glassware setups. Its hollow design offers functional advantages for certain applications, and its chemical resistance and durability make it a long-term investment. However, its fragility, maintenance needs, and higher cost compared to alternatives must be considered.

- Routine laboratory work involving ground glass joints (e.g., flasks, condensers, or reaction vessels).

- Applications where gas exchange or venting is necessary.

- Settings where chemical resistance and cleanability are priorities.

- High-pressure or extreme-temperature applications.

- Environments where frequent handling or potential for impact damage is a concern.

- Budget-conscious setups where disposable or plastic alternatives might suffice.

**Final Recommendation:** If your workflow involves standard glassware and you prioritize durability, precision, and chemical compatibility, the Chemglass CG-8734-29 stopper is a worthwhile purchase. Ensure proper storage (e.g., in a protective case) and regular maintenance to maximize its lifespan. For high-risk or high-volume applications, consider complementary protective measures (e.g., using stopcock grease and handling with care).

Details:

Stoppers, Combination Reagent Bottle/Ground Joint, Hollow.

part #: cg873429 price

• $120.00

specifications plasticwarelabsuppy:

• brand: Chemglass
• mpn: Cg-8734-29
• part type: Stopper
• country of origin: United States
• unit type: Unit
• intended use/discipline: Biological Laboratory, Medical Laboratory, Microbiological Laboratory

seller plasticwarelabsuppy:

• # reviews: 37
• rating: 100.0%
• city: San Diego, California

general plasticwarelabsuppy:

• condition: Used
• Medical, Lab Dental Supplies > Glassware Plasticware > Other Medical Lab Glassware

returns plasticwarelabsuppy:

• policy: No Returns

offer plasticwarelabsuppy:

• availability: In Stock
• quantity: 1
• options: Ship-to-home
• sold: 0
• started: March 2, 2026

payments plasticwarelabsuppy:

• credit card: Mastercard
• wallet: Google-pay
• other

shipping plasticwarelabsuppy:

• type: Calculated
• cost: $19.44
• transit: 3-8 Days
• carrier: FedEx
• class: Standard
• service: FedEx Ground / FedEx Home Delivery

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