Foundry Core Making: Hand Ramming to ABB Robots

In foundry core making, the product is a part nobody outside the foundry sees. A sand core is the shape that sits inside a mould and leaves a hollow in the metal: the water passages in an engine block, the bore of a valve body, the channels inside a pump housing. Cores are fragile, dusty and often heavy, and for most of foundry history they were made, cleaned and set by hand. This post follows core making from rammed sand and baking ovens to core shooters and 3D sand printers, and looks at where ABB robots fit in a modern core room.

A wooden core box and pattern with the sand cores made from them and the finished metal casting. Photo: Glenn McKechnie / Wikimedia Commons (CC BY-SA 2.0)

How core rooms worked before machines

A traditional core started with a core box, a wooden or metal mould shaped like the hollow the casting needed. The coremaker packed damp sand mixed with a binder into the box, rammed it firm with hand tools and scraped it level. With a dump box, the coremaker put a plate over the box, flipped it and let the core slide out. The oldest binder was vegetable oil, mixed with cereal or clay, and an oil sand core was soft until it was baked. Long or thin cores got wires or rods pressed inside to keep them from sagging.

A core worker at Stockham Pipe and Fittings in Birmingham, Alabama, shows a core box and cores for a brass gate valve body, around 1950. Photo: HAER, Library of Congress via Wikimedia Commons (public domain)

Baking happened in core ovens, and the core room became its own department next to the moulding floor. Workers carried trays of green cores to the ovens, waited for them to harden, then filed off the seams by hand and coated them with a refractory wash so the hot metal would not burn into the sand. Core blowers changed the first step. Instead of ramming, a machine used compressed air to blow sand into the closed box. Photos from the Stockham Pipe and Fittings foundry in Birmingham, Alabama, show workers running core blowers around 1950, though those cores still went to the oven afterwards.

A worker runs a core blower that filled core boxes with resin sand using compressed air at Stockham, around 1950. Photo: HAER, Library of Congress via Wikimedia Commons (public domain)

Next came binders that let cores harden inside the box. In 1944 the German engineer Johannes Croning developed the shell process, in which sand coated with a heat-reactive resin cures against a hot pattern. After the war his process came to light in the German patent office and spread to the United States from 1947. Hot box and cold box binders followed, the cold box type cured by a gas passed through the sand. Core shooting machines could now fill, cure and eject a core in one cycle, and by the 1990s photos of an Alabama grey iron foundry show workers whose main job was changing core boxes.

Laempe automated cold box core machines in a grey iron foundry in Birmingham, Alabama, 1994. Photo: Jet Lowe, HAER, Library of Congress via Wikimedia Commons (public domain)

Core printers, cold box cells and ABB foundry robots

Some core rooms now print part of their output. In August 2026 Sarginsons Industries in Coventry became the first UK foundry to invest in inorganic 3D sand core printing, putting £800,000 into a system that prints cores at about 54 litres an hour. The company says it could cut aluminium casting lead times from six to eight weeks to as little as 24 hours, and the inorganic binder nearly eliminates the gases that organic binders release into the metal. In Germany, Laempe Mössner Sinto's first sold L3D-200 sand printer passed its pre-acceptance test at Herborner Pumpentechnik in September 2026.

Two halves of a sand mould with yellow sand cores placed in them, ready for casting. Photo: Glenn McKechnie / Wikimedia Commons (CC BY-SA 2.0)

Printers and shooters both produce cores that still need handling. A core must be taken out of the machine or the print bed, deburred, sometimes glued into a package with other cores, dipped in coating, dried and finally set in the mould without being chipped. These are the tasks robots take on in core rooms, and the environment is rough: silica dust, coating slurry, heat and cleaning with water or steam. ABB sells a Foundry Plus 2 protection option for this, which makes the whole robot IP67 compliant from base to wrist and lets it survive high-pressure steam washing.

A white ABB foundry robot works in steam at a Bühler die casting cell. Photo: ABB

ABB lists sand casting, die casting, cleaning and machining among the jobs for Foundry Plus 2 robots. For small cores, the IRB 1200 Foundry Plus 2 is ABB's compact foundry robot for material handling and machine tending, and the IRB 1300 is offered in Foundry Plus 2 as well. Large core packages for engine blocks call for a bigger arm such as the IRB 6700. ABB robots already work in aluminium casting shops and die casting cells, which our gigacasting post covers. Whether a given core room uses ABB or another brand depends on the integrator, and we found no public ABB core room project to point to.

An ABB IRB 1300 with Foundry Plus 2 protection, built to handle water and dust. Photo: ABB

Where core making goes next

Over the next few years the core room is likely to split in two. High-volume automotive cores will stay on core shooters, with robots unloading, deburring and assembling packages at the shooter's pace. Prototype and low-volume cores will move toward printers like the ones at Sarginsons and Herborner, where a robot could empty the print box, remove loose sand and carry finished cores to coating. Inorganic binders help both routes because they cut fumes in the shop, which also makes the work less unpleasant for the people still in it.

Workers set a large core into a mould with an overhead crane at Stockham's ductile iron foundry, 1993. Photo: Jet Lowe, HAER, Library of Congress via Wikimedia Commons (public domain)

Programming is the part foundries often underestimate. A deburring path has to follow each core's parting line, and every new core box means a new path. Offline programming lets engineers build and test these paths on the core's CAD model before the robot ever touches sand, the way robot cells are planned in RobotStudio. Force control helps with fragile parts, because a robot that feels contact can ease off before a thin core section snaps. Gripping is still awkward: sand cores crumble under hard fingers, so cells often use custom soft grippers or needle grippers for each family of cores.

An ABB robot seen between the open halves of a die casting die. ABB builds protected Foundry versions of its robots for wet, dirty cells. Photo: ABB

Homes only meet sand cores indirectly, inside the cast parts of pumps, boilers and cars. In factories, the first obstacle is money: a printer or a robot cell is a big purchase for a small jobbing foundry. Safety pulls the other way, because silica dust and heavy core packages are the reasons to take people out of the core room in the first place. Then there are skills. Experienced coremakers are retiring, and whoever replaces them has to understand sand and binders as well as robot programs, which few training courses teach together.

An ABB robot beside a melting furnace in the aluminium casting shop of Hermeta in Asperen, the Netherlands. Photo: ABB

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