What Makes UNIK Steel Block Moulds Stand Out in High-Abrasion Concrete Production
High-abrasion concrete mixes-those containing sharp sand, recycled aggregates, or high silica content-accelerate mould wear and reduce service life. For brick plants producing pavers, kerbstones, or hollow blocks with these materials, mould selection becomes a critical factor in production cost and consistency. UNIK's steel block moulds are engineered to address this specific challenge through material selection and heat treatment processes that extend service life beyond industry averages.
The Challenge of Abrasive Concrete
Concrete composition directly affects mould wear. Standard mixes cause predictable surface abrasion over time. Highly abrasive mixes accelerate surface erosion, particularly at cavity edges where material enters and compacts under high vibration . Without correct steel selection and treatment, moulds in these conditions lose dimensional accuracy, produce out-of-spec blocks, and require premature replacement.
Manufacturers using sharp aggregates or recycled materials report cavity wear rates up to three times higher than those using standard mixes . This accelerated wear increases cost per block and creates production interruptions that erode plant efficiency.
Steel Selection for Abrasive Conditions
UNIK matches steel grade to the customer's specific concrete formulation. Standard mixes receive 42CrMo steel, which provides hardness for wear resistance and sufficient toughness for high-cycle operation. For abrasive mixes containing sharp aggregates, tool steel grades such as Cr12MoV or 9CrSi are specified to slow the rate of surface erosion .
The tool steel option undergoes multi-directional forging that transforms cast ingot structures into fine, uniform grain patterns. This grain structure is essential for withstanding the high clamping forces and abrasive cycles typical of high-abrasion production environments .
Heat Treatment as Performance Multiplier
Steel grade defines potential. Heat treatment unlocks it. UNIK applies carburizing to increase carbon content in the surface layer of the mould. Subsequent quenching transforms the surface structure to high hardness (HRC58-62), while the core retains lower hardness (HRC35-40) for flexibility .
The resulting structure provides two distinct performance characteristics:
Hard exterior – resists scratching, gouging, and dimensional loss from concrete flow
Flexible interior – absorbs machine vibration without transmitting crack-inducing stress to cavity corners
This dual-property design prevents the brittle failure common in fully hardened moulds. Surface hardness is maintained at HRC59-62 with a carburized layer thickness of 1.3-1.5mm . Multiple tempering cycles eliminate residual stresses, while optional deep-cryogenic treatment converts retained austenite to martensite, extending service life by over 30% .
The result is a service life of 80,000 to 100,000 cycles under normal production conditions-significantly longer than moulds that fail at 30,000 cycles in similar applications .
Precision Machining for Dimensional Consistency
Beyond materials and heat treatment, UNIK moulds are produced on CNC machining centers with key quality controls:
Surface finish – Ra 1.6 or better, allowing clean demolding and reducing adhesive wear
Corner radius – 3-5mm on all internal corners, eliminating stress concentration points
Dimensional tolerance – held to ±0.1mm, ensuring consistent block dimensions across all cavities
Flatness – whole-board flatness maintained at ≤0.5mm to ensure proper sealing and uniform block thickness
Cavity clearance – unilateral clearance between presser foot and mould cavity is maintained at 0.2mm to 0.4mm, preventing concrete leakage while allowing smooth demolding
These specifications ensure that each block produced matches the design specification exactly, reducing waste and enabling faster installation on site.
The UNIK Difference
UNIK was founded in Quanzhou, Fujian, in 2010-a region with strong manufacturing infrastructure and a historic position on the Maritime Silk Road . The company now exports brick machines and moulds to more than 28 countries, supported by over fifteen years of international trade experience.
Unlike manufacturers that treat steel as a fixed component, UNIK approaches mould steel as a performance variable-adapting to the customer's concrete rather than forcing the customer to adapt to the mould . This product-centric philosophy, combined with carburizing heat treatment and precision CNC machining, produces moulds that deliver consistent performance in high-abrasion concrete production.