Steel Abrasives for Foundry & Casting Industry
Efficient removal of adhered sand, oxide scale, and surface defects from castings before machining or coating. High-cycle abrasives that keep your blast machines productive shift after shift.
The Foundry Cleaning Challenge
Every casting that comes out of a mold carries unwanted guests: adhered green sand, resin sand, or shell-mold ceramic; oxide scale formed during solidification; surface roughness and flash from parting lines. Before a casting can proceed to machining, heat treatment, or coating, this surface burden must be completely removed.
Manual cleaning — hammering, grinding, wire brushing — is slow, inconsistent, and labor-intensive. Shot blasting in tumblast, hanger blast, or table blast machines delivers faster, more uniform results with dramatically lower labor requirements.
The key to efficient foundry blasting is selecting the right abrasive: size matched to casting weight and geometry, hardness appropriate for the base material, and shape optimised for the type of deposit being removed. Macloid Metalix offers steel shot grades from S170 to S660 to cover the full range of foundry casting types.
2000+
Reuse cycles per abrasive charge
4×
Faster than manual cleaning methods
S170–S660
Shot size range for all casting types
< 0.01%
Sulfur content — non-contaminating
Shot Blasting Process in Foundries
Understanding the blasting process helps in selecting the right machine type and abrasive grade for your casting mix
Tumblast Machines
Castings are tumbled in a rotating rubber belt or barrel while abrasive is thrown by a centrifugal wheel. Best for small to medium castings in batch quantities — engine brackets, valve bodies, pump impellers. The tumbling action ensures all surfaces are exposed to the abrasive stream, delivering consistent cleaning without manual repositioning.
Hanger Blast Machines
Castings are hung on rotating hooks or fixtures and passed through a blast cabinet. Ideal for medium to large castings where tumbling would cause damage — manifolds, housing covers, large pump bodies. Multiple blast wheels attack from different angles. Hook spacing and rotation speed are key parameters for complete surface coverage.
Table Blast Machines
Large or heavy castings are placed on a rotating table under a fixed blast wheel. Used for heavy equipment castings, mining components, and large industrial parts that cannot be tumbled or hung. The table rotation ensures even exposure while the casting remains stable. Multiple wheels may be mounted at different heights.
Applications by Casting Type
Different metals and casting processes require different abrasive grades and machine configurations
Iron Castings
Steel Shot S390–S550Examples: Automotive engine blocks, cylinder heads, pump housings, valves, pipe fittings, brake drums
Grey iron and ductile iron castings carry heavy sand adhesion and a thick oxide scale layer from the high pouring temperatures (1350–1450°C). Larger shot sizes (S390–S550) provide the energy needed to break through this layer without distorting the casting geometry. Shot size is selected based on casting wall thickness — heavier sections tolerate larger, more energetic shot.
Steel Castings
Steel Shot S460–S660Examples: Heavy equipment buckets, mining crusher jaws, dragline components, railway couplings, valve bodies for high-pressure service
Steel castings are typically larger and heavier than iron castings and develop thicker, more tenacious oxide scale. They require the most aggressive abrasive — S460 to S660 depending on wall thickness and casting complexity. The higher density of these shot sizes delivers maximum impact energy to break through stubborn scale while the spherical shape avoids sharp stress concentrations on the casting surface.
Aluminum Castings
Steel Shot S170–S280Examples: Automotive wheels, transmission housings, engine covers, aerospace structural components, electronic enclosures
Aluminum is a soft, ductile metal that can be deformed or embedded with steel particles if the wrong abrasive is used. Smaller shot sizes (S170–S280) minimise impact energy while still cleaning the surface. For critical aerospace or automotive applications, stainless steel shot eliminates the risk of iron contamination that would compromise anodising or clear coat adhesion. Cycle times are shorter due to the softer oxide layer.
Die Castings
Steel Shot S110–S230Examples: Zinc alloy door handles, aluminum die cast automotive trim, magnesium laptop chassis, precision instrument housings
Die castings have thin walls, tight tolerances, and highly finished parting-line edges that must not be damaged during cleaning. Very small shot sizes (S110–S230) deliver just enough energy to remove flash and release agent residue without deforming thin sections. Short blast cycles and careful velocity control are essential. Stainless steel shot is preferred for zinc die castings to avoid galvanic contamination.
Recommended Products for Foundry Use
Our steel shot is manufactured to SAE J827 and ISO 11124-3 standards for consistent foundry performance
S170 – S280
Light Castings
Aluminum, zinc die castings under 5 kg. Gentle cleaning without deformation.
S330 – S460
Medium Castings
Iron castings 5–50 kg, steel castings under 20 kg. Standard foundry workhorse grades.
S550 – S660
Heavy Castings
Large steel and iron castings above 50 kg. Maximum energy for thick scale removal.
Recyclability & Working Mix
Macloid Metalix steel shot is manufactured to achieve 2000+ recycle cycles under normal foundry operating conditions. This far exceeds the performance of cast iron grit or natural abrasives, significantly reducing abrasive consumption cost per tonne of casting cleaned.
A healthy working mix contains a distribution of sizes — new, partially worn, and well-worn particles. This blend actually produces better cleaning results than new abrasive alone, as the finer particles reach into recesses that larger particles miss. Regular screen analysis keeps the working mix within specification.
Process Benefits of Shot Blasting
Why leading foundries have moved from manual cleaning to automated shot blasting
Faster Throughput
Tumblast machines clean batches of small castings in 8–15 minutes versus hours of manual work. Dramatically increases cleaning department output without adding headcount.
Consistent Results
Automated blasting delivers the same cleanliness level on every casting in every batch, eliminating the variability inherent in manual cleaning. Reduces rejection rates at inspection.
Reduced Labor
One operator runs a tumblast machine handling hundreds of castings per hour. Manual cleaning of the same volume requires multiple operators with chipping tools, grinders, and wire brushes.
Better Surface Quality
Shot blasting removes scale and sand uniformly without introducing grinding marks, tool marks, or localized removal patterns. Improved surface quality reduces machining allowances and tool wear.
Technical Specifications for Foundry Use
| Carbon content | 0.85 – 1.20% |
| Manganese content | 0.60 – 1.20% |
| Hardness (as-shipped) | 40 – 51 HRC |
| Bulk density | 4.4 – 4.9 g/cm³ |
| Specific gravity | 7.4 – 7.8 g/cm³ |
| Working mix hardness | 40 – 51 HRC (maintained) |
| Recyclability | 2000+ cycles minimum |
| Standard | SAE J827 / ISO 11124-3 |
Optimise Your Foundry Blasting Operation
Our technical team can help you select the right shot size for your casting mix, advise on working mix management, and supply abrasive in bulk bags or drums. Contact us to discuss your foundry's requirements.
Contact Our Technical Team