A foundry chaplet is an essential metal component designed to firmly hold cores in place within the mold during the casting process. 

Cores, typically made from refractory materials such as sand combined with resins, allow for the production of castings with complex internal geometries. We commonly find them in components like pumps, engines, pressure-tight castings, camshafts, and other precision-manufactured parts. 

Since cores are fragile elements, they require a reliable support system to keep them stable. For this reason, any movement or deformation during the pouring of molten metal must be avoided, ensuring the flawless production of the final casting.  

Foundry chaplets serve this purpose: they keep cores in the correct position, preventing them from shifting, deforming, or breaking. These chaplets, designed to strictly adhere to project specifications (such as dimensions, angles, and degrees), are made using advanced manufacturing technologies that ensure precise tolerances and repeatability, even across millions of parts. 

 

Foundry chaplets, which have a long-standing tradition of use, continue to be a reliable and effective solution. These components have seamlessly integrated into the casting process for several years, ensuring flawless results and zero risk to the structure or the casting integrity.  

 

How many types of foundry chaplets exist? 

Foundry chaplets are essential for ensuring casting precision, as they firmly hold the cores in place, guaranteeing the respect of the required tolerances. However, to achieve reliable results and high-quality cast products, it is essential to carefully select and size the chaplets based on a series of parameters, which we will describe shortly.  

Below, we will discuss the main types of foundry chaplets, highlighting their features and applications. The classification will primarily be based on their shape and function, focusing on practical aspects and innovative solutions available to meet the demands of modern production. 

 

Two-plate single-stem foundry chaplets  

Two-plate single-stem chaplets are the most common type of foundry chaplets. They consist of two flat elements, known as plates, which can be circular or square, welded or riveted to a central cylindrical element called the stem, which serves as both a connector and a supporting structure. 

To achieve maximum efficiency, the plates must be precisely welded to the stem and designed to withstand the applied pressure, preventing failure or bending under metallostatic force. Accurate sizing of the plates, particularly in terms of diameter and thickness, is therefore essential to ensure their reliability. 

The stem withstands stresses, adapts to the flow of molten iron, and perfectly integrates into the casting, preventing the formation of empty areas or bubbles, which could potentially compromise the sealing integrity of the casting (leakage). 

Plate perforation (for weight reduction and gas escape) and stem rolling (for improved fusion and integration) represent the main variations of these supports. 

 

 

Two-plate, two-stem chaplets 

Thanks to the larger support surface of the plates and the presence of two stems, two-plate, two-stem chaplets can withstand high loads. Similarly, the riveting of the stems, essential for maintaining the chaplet’s strength, can be replaced with welding, ensuring significantly higher load capacity and making the stems suitable for large-scale castings. 

 

Chaplets with fusion plate 

Chaplets with fusion plates, also known as three-plate chaplets, are ideal for castings that require perfect impermeability and sealing, such as automotive components, pressure-tight castings, boilers, pumps, valves, and pressurized elements. The thin, serrated central plate, which is hole-free and positioned centrally on the stem, guarantees an optimal seal. During casting, even in unfavorable conditions such as low temperatures, the plate melts into the molten metal, creating an effective barrier against the escape of gases, liquids, or vapors – leakage.  

The positioning of the supports within the casting can be ensured by adding a nail, usually welded (welded nail chaplets), of varying diameter and length, or by adding adhesive (pre-glued chaplets). These supports are supplied on silicone paper, allowing the operator to apply them quickly with a consistently controlled layer of glue. 

Finally, for particularly complex shapes, the supports are custom-designed and shaped based on the core’s form in collaboration with foundry technicians, ensuring a tailor-made product for each casting.  

 

Box chaplets 

Box chaplets are entirely made from folded sheet metal and can be provided with or without holes. Produced flat or curved to match the casting’s curvature radius, they easily fuse with castings, even the lightest ones, where they find their main field of application. 

 

Distance spacers and tension rods for engines – water jackets 

With their complex shapes and stringent tolerance requirements, engine castings need specific supports, commonly called distance spacers. These components, custom-designed for each engine model, are essential to ensure compliance with technical specifications, such as precise angles and distances between cylinders. 

The design of distance spacers is a meticulous process that requires close collaboration between the manufacturer and the foundry technicians. The design varies significantly depending on the requirements: they may include a central plate or central stems combined with side plates. In some cases, they are enhanced with fins or clips that closely follow the profile of the water jacket, contributing to precise casting. 

 

Core centering chaplets, camshafts 

Core centering, often cylindrical, is a delicate operation that requires suitable support. Core aligners, for example, used in the production of radiators, camshafts, and cables, are specially shaped clips placed between the cores to ensure perfect alignment. 

 

Polystyrene chaplets for aluminum castings  

Aluminum castings generally use the same types of supports made from aluminum. In recent years, the use of adhesive polystyrene supports (foam chaplets) has increased. These supports, made of plastic and characterized by a cylindrical shape, have the advantage of completely disappearing after casting, a characteristic that makes them increasingly appreciated by foundry technicians. In some cases, the supports are also used before casting and placed between fragile cores to prevent breakage during handling and ramming. 

On this page, you will find all the types of consumables and chaplets for foundry manufactured by Vemek. The real strength of our products lies in the excellent customization capabilities, which allow us to create tailor-made solutions designed and produced to ensure maximum performance and sealing of the metal element. Supports Chaplets are not mere details but essential elements in the casting process.