Laboratory knives and scalpels are available in various designs, for example completely made of metal or stainless steel or with a plastic handle and metal blade.

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Laboratory tools such as knives, tweezers, spatulas, spoons and scoops are indispensable aids in laboratories and pharmacies. © Reichelt

Laboratory knives with plastic or metal housings and replaceable metal blades, also known as cutter knives, are cutting tools for routine use, which can be used to make rough, quick cuts in the laboratory, DIY and handicraft sector. Soft plastics and elastomers such as solid rubber, sponge rubber or cellular rubber as well as paper and cardboard materials can be cut with ease.

Laboratory tools such as knives, tweezers, spatulas, spoons and scoops are indispensable aids in laboratories and pharmacies. © Reichelt

As flat spatulas, double spatulas have flat end pieces on both sides, whereby the corners of the ends can also be rounded. Spoon spatulas or microspoons have a flat end piece on one side, usually rectangular or oval, and a small, spoon-shaped head on the other. They are ideal for transferring small samples of powder or granules. Sample spatulas, on the other hand, can be thought of as small, pointed scoops with a V-profile. They are used for contamination-free removal of powder or granulate samples from bags or sacks.

Spatulas are usually made of stainless steel. They are robust, durable and easy to clean, making them ideal for use in various laboratory environments. Spatulas coated with polytetrafluoroethylene (PTFE) or other non-stick surfaces are particularly useful for preventing substances from sticking. For example, the blades of vibrating spatulas have such a PTFE coating. The vibration of the spatula enables precise dosing when weighing in substances and is triggered by actuating a toothed wheel on the side of the spatula.

Plastic spatulas, made of polystyrene (PS) for example, are lightweight and inexpensive. They are suitable for many applications where metal spatulas are unsuitable, such as when working with aggressive acids or bases.

Tweezers in various designs

The word "tweezers" has its origins in French and means "small pliers" in German. These instruments are used to grip small objects. They consist of two gripping arms that are spring-loaded together at one end. By pressing them together, the tips of the gripper arms can hold objects securely. Tweezers are manufactured as laboratory supplies in many different variations, common materials are metal such as stainless steel or nickel-plated forged steel and plastics such as hard polyethylene (HDPE), polypropylene (PP) or polyoxymethylene (POM). PTFE tweezers, which stand out thanks to the physiologically harmless and almost universally chemically inert material polytetrafluoroethylene, are also available.

Another distinguishing feature is the shape of the tweezers. Pointed tweezers have pointed ends, while flat tweezers have rectangular ends whose corners are often rounded. These wide ends are usually blunt and smooth to avoid damaging the surface of the object to be gripped. This allows flat objects, such as cover glasses in microscopy, to be moved safely. The tips of the tweezers can be straight, angled or curved and often have a ribbed inside, which makes it easier to grip smooth objects.

Special versions of these gripping tools are cutting and cross tweezers, which are often used in electronics laboratories. Cutting tweezers have wide, angled ends whose edges are ground and hardened to cut fine wires made of gold, silver, copper or aluminum. In contrast to conventional tweezers, cross tweezers, also known as clamping tweezers, are closed when not in use; their tips only open when light pressure is applied. This allows small objects to be held securely without continuous hand strain. This type of tweezers is also available in both plastic and metal.