StonyLab 2 Pack Cross Shape Magnetic Stirrer Stir Bars, 40 x 10 mm PTFE-Coated White Stir Mixer

Description

Product Overview

The StonyLab 2-Pack magnetic stirrer bars are engineered for demanding laboratory environments where reliability, durability, and chemical compatibility are essential. Each bar measures 40 × 10 mm and features a distinctive cross‑shape that maximizes magnetic coupling efficiency, ensuring stable and vigorous stirring even in viscous or high‑viscosity solutions. The magnetic core is fully encapsulated in a PTFE (polytetrafluoroethylene) coating, a material renowned for its ultra‑low friction coefficient, excellent chemical inertness, and resistance to a broad temperature range. This PTFE layer not only reduces wear but also protects the magnetic element from corrosive reagents, solvents, and abrasive particles, extending the service life of the stir bar. The bars are autoclave‑safe, allowing for routine sterilization at temperatures up to 121 °C without degradation of performance. With a weight of just 0.65 oz per bar, they provide a strong magnetic response while remaining lightweight, facilitating quick start‑up and rapid changes in stirring speed. The product dimensions of 1.57 × 1.57 × 0.51 in ensure compatibility with most standard magnetic stirrer platforms, making them a versatile addition to any laboratory inventory.

Usage

These stir bars are ideal for a wide spectrum of laboratory applications, ranging from routine chemical synthesis and analytical sample preparation to specialized processes such as polymerization, crystallization, and bioreactor mixing. Their cross‑shape design creates a turbulent flow pattern that enhances mass transfer and promotes uniform temperature distribution throughout the solution, which is particularly beneficial when working with temperature‑sensitive reactions or when precise control of reaction kinetics is required. The PTFE coating ensures that the bars can be used with aggressive acids, bases, organic solvents, and surfactants without risk of degradation, making them suitable for both organic and inorganic chemistry labs. In industrial settings, the bars can be employed in quality‑control laboratories for consistency testing of formulations, as well as in pilot‑scale mixing equipment where reliable magnetic stirring is needed without the complexity of mechanical agitators. Because the bars are autoclavable, they can be sterilized between uses, supporting aseptic techniques in microbiology, cell culture, and pharmaceutical research. Their compact size allows for use in small-volume vessels such as 10 mL vials, 25 mL beakers, and 50 mL conical flasks, while still delivering sufficient torque for larger vessels up to 500 mL when paired with a high‑power magnetic stirrer.

Why Choose Us

StonyLab Scientific has a reputation for delivering high‑quality laboratory accessories that meet rigorous performance standards. The 2‑Pack magnetic stirrer bars are manufactured under strict quality‑control protocols, ensuring each bar meets exact dimensional tolerances and magnetic strength specifications. The PTFE coating is applied using a proprietary process that guarantees a uniform, pinhole‑free layer, providing superior chemical resistance compared to standard polymer coatings. Each bar undergoes a series of durability tests, including repeated autoclave cycles, abrasion resistance trials, and magnetic field strength verification, to confirm that it will perform reliably over an extended service life. In addition to the robust construction, StonyLab offers a one‑year limited manufacturer warranty, reflecting confidence in product durability and providing customers with peace of mind. Technical support is available to assist with installation, troubleshooting, and optimization of stirring parameters, ensuring that users can achieve the best possible results in their specific applications. By choosing StonyLab, laboratories benefit from a combination of innovative design, proven material performance, and responsive customer service that together reduce downtime and improve experimental reproducibility.

Key Features

• Cross‑shape design delivers superior magnetic coupling for stable, high‑speed stirring.
• PTFE coating provides low friction, chemical inertness, and resistance to heat up to 121 °C.
• Autoclave‑safe construction allows for easy sterilization without loss of performance.
• Compact 40 × 10 mm size fits a wide range of vessel diameters and volumes.
• Backed by a one‑year limited warranty and dedicated technical support.

FAQ

What types of solvents can these stir bars be used with?

The PTFE coating is compatible with most organic solvents (such as acetone, ethanol, methanol, and chloroform) as well as aqueous solutions, acids, and bases. It resists degradation from aggressive chemicals, making it suitable for a broad range of laboratory applications.

Can the stir bars be sterilized in an autoclave?

Yes. The stir bars are designed to withstand standard autoclave cycles at 121 °C for up to 30 minutes. The PTFE coating remains intact, and the magnetic core retains its strength after repeated sterilization.

What is the recommended magnetic stirrer power for optimal performance?

For most laboratory stirrers, a power setting between 150 W and 300 W provides adequate magnetic field strength to fully engage the cross‑shape bars. Adjust the speed to match the viscosity of your solution; higher speeds are effective for low‑viscosity liquids, while slower speeds ensure stable stirring of more viscous mixtures.

How does the cross‑shape design improve stirring compared to a standard cylindrical bar?

The cross‑shape creates multiple points of magnetic interaction, generating a more turbulent flow pattern that enhances mixing efficiency. This design also reduces the likelihood of the bar slipping out of the magnetic field, especially in larger vessels or at higher stirring speeds.

Is there a warranty or guarantee if the stir bar becomes damaged?

StonyLab provides a one‑year limited manufacturer warranty covering defects in materials and workmanship. If a stir bar fails under normal use conditions within the warranty period, contact customer support for a replacement or repair.