Hardfacing Welding Electrodes: Technical Specifications & SMAW Guide

Maximizing the operational lifespan of industrial machinery operating under severe abrasive, impact, and high-temperature conditions requires precise application of hardfacing welding electrodes. Shielded Metal Arc Welding (SMAW) remains one of the most versatile and field-adaptable methods for depositing wear-resistant alloy overlays onto carbon steel, low-alloy, and manganese steel substrates. Achieving a successful overlay that resists spalling, premature wear, and thermal fatigue demands a deep technical understanding of electrode core constructions, flux coating formulations, microstructural behavior, and strict adherence to low-dilution welding parameters. This guide provides fabricators and maintenance engineers with a comprehensive engineering breakdown of hardfacing stick electrodes, detailing the critical relationships between alloy selection, operating polarity, heat input management, and effective crack-control strategies for multi-pass buildup.

Hardfacing welding electrodes represent a critical class of specialized consumables engineered to extend the service life of industrial machinery and components subjected to severe wear.

At its core, a hardfacing welding rod is utilized to deposit a wear-resistant layer of alloy metal onto a softer, more ductile base material. Instead of joining two pieces of metal together as traditional welding electrodes do, hardfacing focuses entirely on surface enhancement. By applying these specialized electrodes via the Shielded Metal Arc Welding process, maintenance engineers and fabricators can rebuild worn components back to their original dimensions while simultaneously arming the surface against specific degradation mechanisms such as abrasion, impact, erosion, heat, and metal-to-metal friction.

The physical construction of these electrodes is fundamentally different from standard structural stick electrodes. They are manufactured using varied architectures, including solid core rods, tubular constructions tightly packed with specialized alloy mixes, or carbon steel cores heavily coated with flux formulas containing dense alloys and deoxidizers. The extruded flux coating does far more than just shield the arc; it actively supplies crucial alloying elements directly into the molten weld pool, dictating the final metallurgical properties of the overlay.

Achieving the desired balance of hardness, toughness, and wear resistance requires carefully engineered weld deposit microstructures categorized into distinct alloy systems. These formulations typically span iron-base, nickel-base, and cobalt-base matrices combined with powerful carbide-forming elements like chromium, tungsten, and molybdenum. As we explore the core construction, flux formulations, and specific alloy categories in the following subsections, you will see how these metallurgical choices directly determine the performance of the hardfaced component in harsh operating environments.

Understanding what is a hardfacing welding rod is essential for industrial maintenance and component life extension across demanding sectors.

When examining what is a hardfacing electrode, the definition centers on specialized consumable welding materials designed to deposit a wear-resistant surface onto a structurally sound, yet softer, base metal substrate. Rather than joining two pieces of metal together like traditional structural welding consumables, hardfacing rods are engineered to protect working surfaces from premature degradation. By applying a tough, alloy-rich layer precisely where wear occurs, maintenance engineers can salvage worn components or armor brand-new parts before they ever touch abrasive materials.

To fully understand what are hardfacing electrodes used for, one must look at the grueling operational environments found in industries such as mining, construction, agriculture, and earthmoving. These welding rods are deployed on high-wear components including excavator bucket teeth, crusher jaws, conveyor screws, agricultural tillage tools, and mill hammers. The primary objective is to maximize component service life, dramatically reduce equipment downtime, and eliminate the high costs associated with frequent part replacements by sacrificing a renewable weld overlay instead of the core structural machinery.

Industrial components face multiple destructive forces simultaneously, and hardfacing consumables are specifically formulated to combat these distinct mechanisms. Specifically, these welding rods are engineered to resist metal-to-metal friction, severe sliding and gouging abrasion, high-stress impact, and corrosive environments operating at elevated temperatures. Selecting the correct electrode formulation ensures that the deposited weld metal can withstand the specific combination of forces acting upon the machine part, keeping heavy industrial equipment running efficiently under extreme conditions.

Deploying these specialized protective layers transforms vulnerable machinery components into durable, long-lasting assets capable of withstanding the harshest industrial wear.

The manufacturing architecture of hardfacing welding electrodes directly dictates their performance, alloy transfer efficiency, and wear resistance.

Hardfacing stick electrodes are engineered through several distinct physical manufacturing methods to deliver complex wear-resistant alloys via the Shielded Metal Arc Welding (SMAW) process. Unlike standard structural electrodes that rely primarily on a solid steel core wire for strength, hardfacing consumables utilize specialized internal designs and heavily formulated coatings to deposit wear-resistant overlays onto carbon, low-alloy, or manganese steel substrates.

The manufacturing architecture generally falls into four primary construction types: solid core rods, tubular constructions filled with alloy mixes, carbon steel cores coated with alloys and deoxidizers, and cast cobalt cores featuring heavy extruded flux coatings. Solid core rods utilize a homogeneous alloy steel wire that matches or complements the desired deposit chemistry, often supplemented by the flux coating. Tubular constructions, conversely, consist of a metallic sheath or tube packed with precise blends of alloy powders, carbides, and fluxes. This tubular design allows manufacturers to incorporate high volumes of carbide-forming elements that might be difficult to draw into a solid wire.

Another common configuration features a standard carbon steel core rod surrounded by an extruded flux coating heavily laden with alloying elements, metal powders, and deoxidizers. As the arc melts the mild steel core, the flux coating melts simultaneously, introducing chromium, tungsten, molybdenum, and carbon into the molten pool to achieve the final target chemistry. Finally, specialized cast cobalt cores are paired with heavy extruded flux coatings to produce premium cobalt-base deposits designed to withstand extreme thermal shock and high-temperature corrosion.

In all of these constructions, the heavy extruded flux coating serves a vital metallurgical function. Beyond shielding the molten weld pool from atmospheric contamination and providing easy slag removal, the flux coating acts as the primary vehicle for delivering critical alloying elements. As the electrode is consumed, the chemical components within the heavy flux melt and integrate into the weld deposit, ensuring that the final hardfacing layer possesses the exact hardness, abrasion resistance, and impact toughness required for the application.

Understanding these core and coating configurations allows welders to select the most appropriate electrode type for specialized industrial wear applications.

Understanding the metallurgical properties of weld deposits is essential for selecting the correct hardfacing welding electrodes for specific industrial wear environments.

The microstructure of a hardfacing deposit is fundamentally different from that of structural welds, engineered primarily to resist specific wear mechanisms such as abrasion, impact, erosion, and high-temperature oxidation. During the solidification of hardfacing alloys, a complex matrix forms to support hard, wear-resistant microconstituents. This is achieved by combining base metallic elements—categorized broadly into iron-base, nickel-base, and cobalt-base systems—with potent carbide-forming elements including chromium, tungsten, and molybdenum. As the molten weld pool cools, these carbide formers react with carbon to precipitate hard primary and secondary carbides dispersed throughout a tougher, more ductile binder matrix. The morphology, volume fraction, and hardness of these precipitated carbides dictate the overall wear performance of the overlay.

Iron-base alloy systems are the most widely used and cost-effective hardfacing category, offering a broad spectrum of mechanical properties and wear resistances. Within iron-base deposits, high concentrations of chromium combine with carbon to form massive chromium carbides, which provide exceptional resistance to severe abrasion. Depending on the specific formulation, the surrounding matrix can range from a tough austenitic structure capable of absorbing high impact to a hard martensitic structure designed for severe metal-to-metal wear and moderate abrasion. Other iron-base variants incorporate complex carbides of molybdenum and tungsten to maintain hardness and wear resistance at elevated operating temperatures.

Cobalt-base alloys, commonly recognized by industry standards such as AWS A5.21 (including grades like ERCoCr-A, ERCoCr-C, and grades 1, 6, 12, and 21), are legendary for their performance in extreme environments. Their microstructure consists of complex tungsten and chromium carbides dispersed within a solid-solution cobalt-rich matrix. Cobalt possesses a unique crystallographic transformation characteristic that imparts exceptional retention of hot hardness, red hardness, and resistance to thermal shock, corrosion, and metal-to-metal wear across wide temperature ranges where iron-base alloys would rapidly degrade.

Nickel-base alloys fill a crucial niche where high-temperature strength, severe corrosion resistance, and moderate abrasion intersect. These low-melting-point formulations often utilize specialized matrices, such as nickel-silicon-boron systems. During solidification, boron and silicon act as powerful fluxing agents and form hard borides and silicides that enhance wear resistance while maintaining the exceptional ductility and oxidation resistance characteristic of high-nickel alloys.

Ultimately, the interaction between these alloying elements and their precipitation behavior dictates service life. In carbide composites, for example, crushed tungsten carbide particles or vanadium tungsten carbides are embedded directly within ductile matrices like nickel-silicon-boron or austenite. The softer matrix wears away preferentially during service, leaving the ultra-hard carbide particles protruding to face and resist abrasive media, thereby optimizing the balance between impact toughness and extreme abrasion resistance.

By tailoring the balance of iron, nickel, or cobalt matrices with strategic carbide-forming elements, manufacturers can engineer hardfacing deposits custom-built to withstand the most punishing industrial wear conditions.

Understanding these foundational construction methods and microstructural goals is essential for selecting the correct electrode grade for your specific industrial application.

Selecting the appropriate hardfacing electrode requires a precise understanding of alloy classifications, hardness ratings, and mechanical properties to match specific wear mechanisms in industrial applications.

Cobalt-base formulations, standardized under classifications such as AWS A5.21 (including ERCoCr-A, ERCoCr-C, and specialized grades like 1, 6, 12, and 21), are engineered to maintain exceptional resistance to wear, impact, and thermal shock across extreme temperature ranges. These alloys utilize a heavy extruded flux coating on a cast cobalt core to supply necessary alloying elements, resulting in deposits that resist oxidation and corrosion at elevated temperatures where traditional iron-base steels fail.

In parallel, low-melting-point nickel-base alloys—typified by AWS A5.21 ERNiCr-B—offer superior resistance to severe corrosion combined with high-temperature metal-to-metal wear and moderate abrasion. These compositions are frequently utilized in chemical processing and power generation environments where components are subjected to both corrosive media and elevated thermal cycles.

Iron-base systems and carbide composites round out the spectrum for heavy industrial applications, providing options that range from crack-resistant, forgeable formulations yielding 52 to 58 HRC for moderate abrasion, to highly specialized non-machinable, non-forgeable low-hydrogen and non-chromium formulations designed to withstand severe mineral abrasion. Furthermore, carbide composites containing crushed tungsten carbide of controlled mesh sizes within robust matrices provide extreme abrasive wear resistance for earthmoving and mining equipment.

While specialized alloy electrodes are engineered for specific wear environments, fabricators frequently question whether standard structural consumables like E7018 can be utilized for hardfacing applications. While E7018 provides excellent ductility and crack resistance for structural joining, its low carbon and alloy content yield an as-deposited hardness generally limited to around 150-200 Brinell, making it suitable only for low-stress base metal buildup or as a cushioning layer prior to applying specialized hardfacing deposits.

Non-ferrous hardfacing welding electrodes provide exceptional performance in extreme operating environments where standard steel alloys quickly degrade.

Cobalt-base alloys, widely recognized under classifications such as AWS A5.21 ERCoCr-A, ERCoCr-C, and specific industrial grades like grades 1, 6, 12, and 21, serve as the gold standard for applications requiring resistance to severe wear, oxidation, and thermal shock. These alloys maintain their hardness, strength, and corrosion resistance across exceptionally wide temperature ranges, often performing reliably up to elevated red-heat conditions without losing structural integrity. Grade 1 offers extreme abrasion resistance due to a higher volume of carbides, whereas Grade 6 provides an optimal balance of ductility, impact resistance, and metal-to-metal wear resistance, making it the most versatile choice for valves, hot shear blades, and high-temperature fluid handling components. Grade 12 bridges the gap between grades 1 and 6, offering enhanced edge retention, while Grade 21 excels in high-temperature metal-to-metal contact subjected to severe thermal cycling.

In contrast, low-melting-point nickel-base alloys, such as those governed by AWS A5.21 ERNiCr-B, are engineered for unique industrial demands where resistance to chemical corrosion, scaling, and severe thermal fatigue takes precedence. Nickel-base hardfacing deposits exhibit remarkable ductility, allowing them to absorb heavy mechanical and thermal stresses without cracking. They perform exceptionally well in corrosive liquid environments and at elevated temperatures where iron-base overlays would rapidly oxidize or corrode. By selecting the appropriate non-ferrous formulation, engineers can significantly extend the service life of critical components exposed to aggressive chemical and thermal degradation.

Understanding the precise mechanical properties of cobalt and nickel-base electrodes ensures optimal alloy selection for extreme industrial environments.

Iron-base systems and carbide composites offer versatile, heavy-duty overlay solutions designed to withstand extreme industrial wear environments.

Specialized iron-base hardfacing systems are engineered to address specific wear mechanisms by balancing alloy chemistry, hardness, and toughness. At one end of the spectrum are crack-resistant, forgeable iron-base formulations. These electrodes typically yield a deposited hardness ranging from 52 to 58 HRC, making them exceptionally well-suited for applications involving moderate abrasion combined with low to moderate impact. Because they can be forged and machined under specific conditions, they are frequently utilized for rebuilding components that require post-weld mechanical finishing, such as certain types of dies, shears, and carbon steel machinery parts.

Conversely, extreme operating conditions demand non-machinable and non-forgeable iron-base systems. These low-hydrogen, non-chromium formulations are intentionally designed for severe abrasion or aggressive metal-to-metal wear environments where impact forces are minimal. By eliminating softer matrix phases and maximizing wear-resistant alloy constituents, these electrodes deliver superior resistance to abrasive soil, sand, minerals, and sliding metal friction, significantly extending the service life of earthmoving equipment, agricultural tillage tools, and industrial chute liners.

In addition to traditional alloyed iron-base deposits, carbide composites represent an elite tier of hardfacing materials optimized for extreme abrasive wear. These specialized electrodes and tubular products distribute crushed tungsten carbide of controlled mesh size, or advanced vanadium tungsten carbides, throughout a tough supporting matrix such as nickel-silicon-boron or specialized steel alloys. As the softer matrix wears away during operation, the exposed carbide particles bear the brunt of the abrasive media, cutting and deflecting abrasive particles. This self-sharpening characteristic makes carbide composites ideal for severe earth-boring augers, oilfield drilling tools, and mining dredge components.

For structural rebuilding and high-impact applications on cast steel and manganese steel base metals, austenitic manganese electrodes and modified austenitic stainless steels are indispensable. Austenitic manganese weld deposits possess unique work-hardening properties; under heavy impact and compressive forces, the surface rapidly hardens while retaining a tough, ductile core that resists catastrophic cracking. This makes them the premier choice for repairing heavy industrial components like railway frogs, rock crusher jaws, and heavy-duty impact hammers operating under severe cyclical stress.

Selecting the correct iron-base or carbide composite electrode ensures that the hardfacing overlay matches the exact mechanical and tribological demands of the application.

Understanding the limitations and proper applications of standard structural electrodes is critical when performing successful component restoration.

A common question among fabricators and maintenance technicians is whether you can use E7018 electrodes for hardfacing applications. The direct answer is no; E7018 is fundamentally a low-hydrogen structural carbon steel electrode designed for high-strength joining, not for resisting wear. It lacks the alloy content, specialized carbide structures, and high hardness ratings (HRC) required to withstand severe abrasion, impact, or metal-to-metal friction. If applied directly as a wear surface, an E7018 deposit will wear away rapidly under operational stress.

However, E7018 plays a vital and officially recognized supporting role in multi-pass hardfacing procedures. It is frequently utilized to rebuild heavily worn base metals back to their original dimensions or to serve as a ductile, crack-resistant "buildup" or buffer layer. When overlaying high-carbon or low-alloy steels with extremely hard, brittle surface alloys, applying a cushion layer of E7018 prevents underbead cracking by absorbing mechanical stresses and providing a tough, impact-resistant transition zone between the substrate and the hardfacing overlay.

Therefore, while E7018 cannot provide the wear protection needed for prolonged equipment service life, it remains an indispensable tool for preliminary dimensional restoration and stress relief before the actual hardfacing welding electrodes are applied.

Always reserve E7018 for structural buildup and structural integrity, leaving the surface protection entirely to dedicated alloyed hardfacing electrodes.

A thorough review of these material grades provides the foundation for evaluating specific electrode formulations, cobalt-base capabilities, and iron-base systems before establishing welding parameters.

Mastering the application of hardfacing welding electrodes via Shielded Metal Arc Welding (SMAW) requires strict adherence to specialized operating parameters to ensure maximum wear resistance and deposit integrity.

Unlike structural joining electrodes, hardfacing stick electrodes demand specific handling regarding current settings, polarity, and arc manipulation. Operators must carefully match the amperage to the electrode diameter—such as utilizing 115 to 160 amperes on either alternating current or direct current electrode positive for a 5/32-inch electrode. Maintaining a slightly longer arc length than typical structural welding helps stabilize the globular metal transfer and promotes smooth slag removal, though tubular electrodes must never be crowded into the workpiece to prevent rapid overheating.

Thermal management is another critical factor in successful hardfacing applications. Stick hardfacing inherently generates higher heat input and greater base metal dilution than continuous wire processes. To prevent the underlying substrate from diluting the alloy overlay and reducing its hardness, welders must employ lower operating parameters and adopt techniques that minimize base metal penetration.

When laying down the weld metal, both stringer bead and weave bead techniques can be utilized depending on whether the goal is surface buildup, metal-to-metal wear resistance, or impact protection. Furthermore, fabricators must understand the natural solidification behavior of these overlays, where carbide precipitation often induces controlled cross-checking relief cracks unless specific crack-free alloy formulations are selected.

Mastering the electrical parameters and arc manipulation techniques required for hardfacing welding electrodes is essential to achieve a sound, wear-resistant overlay.

When utilizing hardfacing stick electrodes, understanding the operational dynamics of the welding circuit ensures stable deposition and prevents premature electrode breakdown. Unlike standard structural welding consumables, hardfacing electrodes are specifically engineered to operate with a distinct globular metal transfer, delivering a smooth arc action accompanied by easy slag removal. Welders must carefully regulate the electrical current and maintain proper technique to balance deposition rates with the integrity of the overlay.

Improper handling of the electrode during the shielding metal arc welding (SMAW) process can quickly degrade the performance of the weld deposit. For instance, forcing a tubular electrode too close to the base metal chokes the arc, generating excessive localized resistance heat that melts the internal alloy constituents prematurely before they can be properly transferred to the weld pool. By maintaining the recommended arc length and strictly adhering to specified amperage ranges, operators achieve a uniform alloy distribution and a sound metallurgical bond.

Adhering to these established electrical parameters and arc control guidelines optimizes the transfer of hardfacing alloys and sets the stage for effective thermal management.

Controlling thermal input is one of the most critical factors when depositing wear-resistant alloys via shielded metal arc welding.

Base metal dilution occurs when the intense heat of the electric arc melts not only the hardfacing electrode but also a portion of the underlying substrate. When this parent material mixes into the molten weld pool, it alters the chemical composition of the deposited alloy. Because hardfacing electrodes are engineered with precise carbon and alloy ratios to maximize hardness, abrasion resistance, or impact toughness, unwanted mixing with a softer structural steel base metal degrades the performance of the final overlay. If the chemistry is excessively diluted, the microstructure fails to develop the desired carbide precipitation or matrix hardness.

When comparing processes, stick hardfacing inherently generates significantly more heat and base metal penetration than continuous-feeding processes like a hardfacing mig wire or flux-cored alternative. Because manual stick electrodes rely on electrical resistance and heavy flux coatings that concentrate high thermal energy at the arc point, the risk of deep substrate melting is much higher. Welders must actively compensate for this thermal characteristic by utilizing the lowest possible operating parameters. Adjusting amperage to the lower end of the manufacturer's recommended range ensures minimal penetration while still achieving adequate fusion.

Failing to manage heat input and allowing excessive base metal dilution creates a cascading failure in surface protection. Not only does the soft overlay wear away prematurely under abrasive service conditions, but low deposition efficiency wastes expensive alloy materials. By keeping travel speeds controlled, avoiding excessive weaving that dwells heat in a single area, and maintaining a tight grip on amperage limits, operators can protect the integrity of the alloy chemistry and extend the operational lifespan of the component.

Mastering heat management directly dictates whether a hardfacing deposit will meet its expected wear-life benchmarks.

Selecting the appropriate deposition technique is critical for optimizing the performance and longevity of hardfacing overlays applied via Shielded Metal Arc Welding (SMAW).

Stringer beads and weave beads each serve distinct metallurgical and structural purposes when depositing wear-resistant alloys. Understanding when and how to apply each technique prevents premature failure, excessive base metal dilution, and destructive thermal distortion. The fabricator must evaluate the component geometry, the nature of the wear mechanism, and the alloy's sensitivity to heat input before initiating the arc.

Stringer beads—narrow, linear passes deposited with minimal sideways manipulation—are the preferred technique for minimizing heat input, thermal shock, and part distortion. When hardfacing smaller components, sharp edges, or thin sections, stringer beads limit the total thermal energy transferred into the base metal. This reduction in heat input restricts the size of the heat-affected zone (HAZ) and lowers the percentage of base metal dilution, ensuring that the deposited alloy retains its nominal chemical composition and designed hardness. Furthermore, multiple parallel stringer beads can be laid down with overlapping patterns to build up worn surfaces while providing inherent stress distribution across the overlay.

In contrast, weave beads involve oscillating the electrode side-to-side to cover a wider surface area in a single pass. Weave beads are highly efficient for broad surface coverage on large, heavy components such as tractor idlers, crusher mantles, or large industrial plates subject to severe abrasion and moderate impact. By utilizing a weave technique, operators can achieve higher deposition rates and smoother, more uniform surface profiles, which significantly reduces post-weld grinding and finishing time. However, because weave beads introduce a larger volume of concentrated heat into the workpiece, they must be used cautiously on alloy steels or components prone to cracking and warping.

Beyond bead width and heat management, the directional layout of the weld passes plays a vital role in resisting service wear. As a general rule of thumb, hardfacing beads should be deposited perpendicular to the primary flow direction of abrasive materials, soil, or rocks. For example, on agricultural tines, bucket lips, or earth-moving chutes, laying stringer or weave beads across the path of material flow ensures that the abrasive medium continuously overrides successive weld ridges rather than carving out parallel grooves between them. This cross-flow orientation maximizes the mechanical interlock between the abrasive particles and the wear-resistant overlay, dramatically extending the operational lifespan of the component.

Mastering the balance between stringer and weave techniques ensures that the hardfacing deposit delivers maximum wear resistance without compromising the structural integrity of the underlying metal.

Understanding and managing crack formation is a critical aspect of successfully applying hardfacing welding electrodes to heavy-duty industrial components.

During the solidification of high-alloy hardfacing deposits, severe thermal contraction forces interact with rigid base metals to create immense internal stresses. In many high-alloy formulations, particularly those rich in chromium carbides, the weld metal naturally accommodates these stresses through a phenomenon known as cross-checking. Cross-checking refers to the network of fine, transverse relief cracks that form at regular intervals across the face of the weld bead as the deposit cools. This cracking occurs due to carbide precipitation and the inherently low ductility of high-hardness microstructures when subjected to rapid thermal contraction.

Far from indicating a structural defect, cross-checking is frequently an intended and desirable metallurgical characteristic. These micro-fissures act as internal stress relievers, drastically reducing the overall residual stress trapped within the overlay. Without this natural stress-relief mechanism, the massive shrinkage forces could easily cause the entire hardfacing overlay to delaminate, warp, or completely spall off the base metal. Welders must evaluate each specific application to determine whether cross-checking is acceptable, as certain crack-free alloy formulations exist specifically for environments where any form of fracturing could compromise corrosion resistance or lead to premature fatigue failure.

When utilizing crack-sensitive alloys or applying multi-pass buildups where cracking must be strictly controlled, rigorous thermal management is mandatory. Strict preheating protocols—often ranging from 300°F to over 600°F—are required to slow down the cooling rate and reduce thermal shock. Furthermore, maintaining tightly controlled interpass temperatures prevents excessive heat accumulation, which can otherwise coarsen the grain structure, exacerbate base metal dilution, and trigger catastrophic spalling or delayed cracking during post-weld cooling.

By respecting the metallurgical realities of high-hardness overlays and applying proper thermal controls, technicians can effectively harness cross-checking to produce durable, long-lasting wear surfaces.

Understanding these core SMAW operating principles provides the foundation for exploring precise current controls, advanced heat management strategies, specific bead techniques, and comprehensive crack-control methods.

Selecting the optimal hardfacing welding electrode requires a precise balance between the specific wear mechanism—whether severe abrasion, high impact, metal-to-metal friction, or elevated temperatures—and the microstructural capabilities of the chosen alloy system. By matching the appropriate cobalt-base, nickel-base, or specialized iron-base formulation to the substrate and operating environment, fabricators can drastically extend component service life. Coupled with disciplined SMAW techniques, such as maintaining lower amperages, minimizing base metal dilution, and managing cross-checking relief cracks, hardfacing procedures yield durable, reliable surface overlays that stand up to the most punishing industrial demands.