A graduated cylinder is a tall, narrow vessel with printed scale markings used to measure the volume of a liquid. Its narrow diameter means small changes in volume produce easily readable changes in liquid height, making it significantly more accurate than a beaker for volume measurement. Graduated cylinders are standard equipment in virtually every science lab — from middle school classrooms to professional research facilities.

They are not designed for mixing, heating, or long-term storage. Their sole purpose is measuring liquid volumes with moderate precision. For work requiring higher volumetric accuracy, such as analytical solution preparation, a volumetric flask is the correct tool. For everyday measurement tasks — dispensing reagents, recording volumes, checking quantities — graduated cylinders are the standard.

Glass graduated cylinders are made from borosilicate glass, which provides superior chemical resistance, a sharply defined meniscus for more precise readings, and permanent printed graduations that won't wear off. Plastic graduated cylinders are made from polypropylene, which is shatter-resistant, lightweight, and suitable for most aqueous solutions.

Glass is preferred for analytical accuracy, chemical compatibility with organic solvents, and professional lab work. Plastic is preferred for elementary and middle school classrooms, field sampling, and any setting where breakage is frequent or costly. The most significant practical difference is meniscus readability — glass produces a more defined meniscus curve, making it easier to take an accurate reading. For most teaching purposes, this difference is minor. For quantitative lab work, glass remains the standard.

Graduated cylinders are available in sizes from 5ml to 2,000ml in both glass and plastic. The most commonly used sizes in teaching labs are 10ml, 25ml, 50ml, 100ml, 250ml, and 500ml. Smaller cylinders (10ml, 25ml) have finer graduation marks and provide better precision for small-volume measurements. Larger cylinders (500ml, 1,000ml) handle bulk measurement tasks.

A well-stocked teaching lab keeps a range: 10ml and 25ml for precise small-volume work, 100ml as the everyday workhorse, and 250ml or 500ml for larger volumes. The 100ml graduated cylinder is the single most commonly ordered size — if you're buying one size for a class set, that's the one.

Read a graduated cylinder at eye level, looking at the bottom of the meniscus — the curved surface formed where the liquid meets the cylinder wall. Water and most aqueous solutions form a concave meniscus that curves downward in the center. Place your eye level with the lowest point of this curve and read the graduation mark at that level. Reading from above or below introduces parallax error and produces an inaccurate measurement.

For mercury or other liquids that form a convex meniscus (curving upward in the center), read at the highest point of the curve instead. Glass cylinders generally produce a more visible and well-defined meniscus than plastic, which is one reason glass is preferred for precise measurement in most lab settings. Teaching students proper meniscus reading technique is one of the first measurement skills covered in any science curriculum.

No. Graduated cylinders — whether glass or plastic — should never be heated. Heat can warp the cylinder walls, distort the graduation markings, and permanently compromise measurement accuracy. Glass cylinders may crack from thermal stress since they are not designed for the uneven heating that occurs on a hot plate or over a flame. Plastic cylinders will soften and deform well below the boiling point of water.

If you need to measure a hot liquid, allow it to cool first or transfer it to a heat-resistant vessel (like a borosilicate beaker) for heating and then to the cylinder for measurement after cooling. Graduated cylinders are precision measurement instruments, not reaction vessels — keeping them away from heat sources protects your investment and your data.

Class A graduated cylinders meet tighter manufacturing tolerances than Class B, delivering higher volumetric accuracy. For example, a 100ml Class A cylinder is accurate to approximately ±0.5ml, while a Class B version has a wider tolerance. Class A cylinders also carry an individual serial number and a certificate of calibration traceable to national standards.

For most teaching labs, Class B graduated cylinders provide sufficient accuracy. Students are learning measurement technique and concepts, not performing analytical quantitation. For university analytical chemistry, quality control labs, and any work where measurement accuracy directly affects reported results, Class A cylinders are the appropriate choice. Plastic graduated cylinders are not classified as A or B — they have their own (wider) tolerance specifications and are best suited for general-purpose measurement.

A cylinder protector is a plastic bumper guard that fits around a glass graduated cylinder to cushion it against impact and reduce the risk of breakage if the cylinder is knocked over or dropped. Protectors snap or slide onto the cylinder and add a raised rim above and below the glass body, absorbing shock on impact. They are especially valuable in classroom settings where cylinders are handled frequently by students.

Cylinder protectors are an inexpensive way to extend the life of glass graduated cylinders — a single protector can prevent dozens of replacements over a school year. For labs that prefer the accuracy of glass but face the breakage rates of a teaching environment, cylinder protectors offer the best of both worlds.

Plan for one graduated cylinder per lab station in each size your curriculum requires. A classroom with six lab stations running general science needs at minimum six 100ml cylinders. If your curriculum includes experiments requiring precise small-volume measurement, add a set of 10ml or 25ml cylinders. For courses that frequently measure larger volumes, add 250ml or 500ml cylinders.

Graduated cylinders break — especially in teaching environments. Order 10–20% more than the minimum to have replacements on hand. Running short mid-semester disrupts lab sessions and delays learning. Many educators keep a reserve of the most-used sizes (typically 100ml) in the prep room so broken cylinders can be swapped immediately.

The Lab Stockroom carries graduated cylinders in borosilicate glass and polypropylene plastic across the full size range — from 10ml to 2,000ml — with transparent pricing and fast shipping from New York. Class-set quantities and volume pricing are available.

Educators, school districts, and institutional procurement teams can purchase online, request a formal quote, or submit a purchase order. Cylinder protectors are available as a separate add-on for any glass cylinder size. If you're outfitting a new lab or restocking across multiple classrooms, contact the team for a quantity quote. Tax-exempt purchasing is available for qualifying institutions.