Industrial Bearings by Application: Cement, Steel, Mining, Food Processing, CNC

Industrial bearings are rolling element assemblies engineered to sustain heavy loads, extreme temperatures, and harsh operating environments specific to each manufacturing sector — from cement rotary kilns to precision CNC spindles. Unlike commercial-grade bearings, industrial bearings must achieve calculated service lives measured in tens of thousands of hours, often running continuously around the clock under dust, vibration, and shock loading.

Across Vietnam, eight core industrial sectors account for over 80% of annual industrial bearing imports. Each sector imposes distinct requirements on internal clearance, cage material, grease type, and precision class. This article examines bearing requirements for each sector in detail, with specific bearing designations, operating parameters, and field-proven lessons from Vietnamese plants.

For foundational bearing knowledge, see What is a bearing? before continuing.

Cement — Rotary Kiln, Ball Mill, ID Fan

The cement industry ranks among the largest bearing consumers in Vietnam. Each plant producing 2,500–5,000 tonnes of clinker per day uses hundreds of bearing sets at critical positions: rotary kiln, ball mill, ID fan, and conveyor systems.

Rotary kiln — SRB 232xx through 240xx

Kiln support rollers carry radial loads ranging from 800 kN to 2,500 kN at rotation speeds of only 1–4 rpm. Spherical roller bearings (SRB) in the 232xx, 233xx, 238xx, and 240xx series with C4 clearance are the standard choice. C4 clearance compensates for thermal expansion as the kiln shell exterior reaches 250–350°C. High-temperature grease based on polyurea or lithium complex thickener rated for continuous 200°C service is mandatory (SKF, Bearing selection for rotary kilns).

Thrust rollers that prevent axial kiln migration use SRB or spherical roller thrust bearings in the 292xx–294xx series. The girth gear drive train also demands four-row tapered roller bearings or large-bore SRB.

A cement plant in Hai Duong province extended support roller bearing life from 18 months to 36 months by switching from C3 to C4 clearance and replacing standard lithium grease with polyurea-based grease rated to 220°C.

Ball mill — SRB 222xx through 223xx, brass cage

Ball mill trunnion bearings absorb impact loading from grinding media falling inside the chamber. SRB designations such as 22228, 22236, and 22244 with brass cages (suffix CA or MA) are preferred because brass cages tolerate impact loading better than pressed steel cages (FAG, Rolling bearing catalogue HR1). C3 clearance is typically sufficient since trunnion temperatures remain lower than kiln positions.

ID fan — DGBB 6316 through 6320 C3

ID fan motors rated 200–800 kW use deep groove ball bearings (DGBB) in the 6316, 6317, 6318, and 6320 range with C3 clearance. Ultra-fine clinker dust below 10 μm is the primary threat — contact seals (2RS) alone are insufficient, requiring labyrinth seals combined with positive air purge (NSK, Cement plant bearing solutions).

Further reading: Cement plant bearings (deep-dive), Spherical roller bearings, SRB products.

Steel & Metallurgy — Hot Rolling, Furnace, Crane

Vietnam's steel industry, with capacity exceeding 30 million tonnes per year, imposes the most severe demands on bearings: temperatures reaching 300°C near reheating furnaces, extreme shock loads at rolling stands, and continuous vibration on overhead cranes.

Hot rolling mill — Four-row tapered roller bearings

Work rolls and backup rolls in hot rolling stands use four-row tapered roller bearings (TRB) in the 330xxx–332xxx series. Each bearing must withstand radial loads of 1,000–4,000 kN with additional shock when the steel billet enters the roll gap. Circulating oil lubrication with 10 μm filtration is mandatory — grease cannot dissipate enough heat (Timken, Steel mill bearing solutions).

A steel mill in Ba Ria – Vung Tau province reduced rolling stand downtime by 40% after installing online temperature and vibration sensors on all roll chock housings, enabling early detection of bearing deterioration before failure.

Reheating furnace — Heat-resistant SRB

Conveyor rollers inside reheating furnaces use SRB in the 22320 E through 22340 E range with C4 clearance and brass cages. Radiant heat from billets at 1,100°C causes external housing temperatures of 150–250°C. Solutions include insulated housings, water-cooled housing circulation, and PFPE or polyurea grease rated to 260°C.

Overhead crane — SRB and DGBB

Cranes handling billets and coils weighing 20–30 tonnes use SRB 22220–22228 for bridge travel wheel shafts and DGBB 6316–6320 for hoist motors. Shock loading during coil lifting requires C3 clearance and outer ring anti-rotation pins.

Further reading: Tapered roller bearings, TRB products, Bearing lubrication.

Mining — Crusher, Conveyor, Vibrating Screen

Vietnam's mineral extraction industry — from Quang Ninh coal to Central Highlands limestone — operates bearings under dust, moisture, and continuous shock loading. Bearing service life at mine sites typically reaches only 50–70% of clean workshop conditions (SKF, Mining industry bearing guide).

Jaw and cone crushers

Eccentric shafts in jaw crushers use SRB 22228 EK/C3 and 22232 EK/C3 with brass cages. Shock loading when hard rock enters the crushing chamber creates peak loads 3–5 times the nominal rating. C3 clearance is mandatory for eccentric shafts; C4 when ambient temperature exceeds 50°C.

Cone crushers use large tapered roller bearing pairs on the main shaft — for example, TRB series 332xxx or SRB 23156 CA/W33 for 1,000-tonne-per-hour cone crushers.

Ore conveyors — SRB 22216 through 22220

Head and tail pulleys on conveyors spanning 500–2,000 m use SRB 22216 E, 22218 EK, and 22220 EK in SNL or SAF plummer block housings. Housings require triple-labyrinth seals combined with grease purge chambers to prevent mud and ore slurry ingress.

A coal mine in Quang Ninh province reduced conveyor bearing failure rates by 60% after replacing double-lip seal housings with triple-labyrinth seal housings paired with automatic grease pumps on 4-hour cycles.

Vibrating screens — Dedicated vibration bearings

Vibrating screens use special cylindrical roller bearings designed for centrifugal loading — such as FAG vibrating screen bearings or NSK 22xx EM series. Requirements include precise dynamic balancing, mandatory C4 clearance, and specialty grease rated for accelerations exceeding 10 G.

Further reading: Spherical roller bearings, Construction equipment bearings, SRB products.

Food & Beverage — Hygiene, Corrosion Resistance, Food-Safe Grease

The food and beverage processing sector inverts the priorities of heavy industry: the primary concerns are not load capacity but hygiene, corrosion resistance, and food safety. Bearings must comply with FDA 21 CFR 178.3570, EU Regulation 1935/2004, and HACCP standards (NSK, Food and beverage bearing solutions).

NSF H1 grease

Grease carrying NSF H1 certification (safe for incidental food contact) is mandatory for every bearing within production zones. Synthetic PAO-based grease with aluminum complex or polyurea thickener achieving NSF H1 registration is the most common choice. NSF H1 grease costs 3–5 times more than standard grease, but it is a non-negotiable regulatory requirement.

Stainless steel housings and IP69K seals

Plummer block housings manufactured from AISI 316L stainless steel withstand high-pressure washdown (CIP/SIP) with alkaline or acidic cleaning solutions. Seals achieving IP69K rating resist 80 bar water pressure at 80°C — the standard for washdown equipment in dairy, brewery, and beverage plants.

Common stainless steel bearings include SS 6204 2RS, SS 6205 2RS, and SS 6206 2RS in AISI 440C or AISI 316 (for acidic environments). Larger stainless SRB serve mixers and centrifuges.

Traceability and foreign body control

A dairy plant in Binh Duong province requires all replacement bearings to carry material certificates, production lot traceability codes, and post-installation metal detection verification. This system supports FSSC 22000 audit compliance.

Further reading: Ball bearing products, Bearing maintenance.

CNC & Precision Machining — Angular Contact Bearings, P4/P2 Precision

CNC machines, grinding machines, and precision lathes demand bearings with extremely low runout and very high rotational speed capability. CNC spindles operating at 8,000–40,000 rpm require angular contact ball bearings (ACB) in precision class P4 (ABEC 7) or P2 (ABEC 9) per ISO 492 (SKF, Super-precision bearings catalogue).

7xxx series for CNC spindles

Angular contact ball bearings in the 7005, 7008, 7010, 7012, and 7014 range with 15° contact angle (suffix C or AC) or 25° contact angle (suffix E or BE) are standard. Common mounting arrangements:

• DB (back-to-back): supports radial + bidirectional axial load, suitable for most milling spindles.
• DT (tandem): increases unidirectional axial load capacity, used for drilling spindles.
• DBD or TBT (triplex): three bearings in back-to-back + tandem arrangement, for grinding spindles exceeding 20,000 rpm.

High-speed grease and oil-air lubrication

High-speed grease based on synthetic ester with barium complex or lithium complex thickener achieves speed factor (n·dm) values exceeding 1,500,000 mm·rpm. For spindles above 25,000 rpm, oil-air lubrication replaces grease — each 0.01–0.03 ml oil droplet is carried by compressed air to the bearing contact zone.

Preload influence

Preload determines spindle stiffness and speed limits. Light preload (suffix L) for high speed, medium preload (suffix M) for balanced speed-stiffness, and heavy preload (suffix H) for heavy cutting at lower speeds.

A mold-making workshop in Ho Chi Minh City improved mold surface finish from Ra 0.8 to Ra 0.2 μm after upgrading spindle bearings from P5 to P4 class and switching to oil-air lubrication.

Further reading: Angular contact bearing products, Electric motor bearings.

Thermal Power — Insulated Bearings, Large Motor SRB

Coal and gas-fired thermal power plants in Vietnam employ large motors (2,000–20,000 kW) for boiler ID fans, feedwater pumps, circulating water pumps, and coal mills. Bearings for large motors and generators must address two sector-specific problems: shaft currents and heavy loading (SKF, INSOCOAT bearings).

Shaft currents and INSOCOAT insulated bearings

Variable frequency drives (VFD) controlling motors generate parasitic shaft voltages. This current discharges through bearings, creating electrical discharge machining (EDM) pitting on raceways. Solutions include:

• INSOCOAT insulated bearings (SKF): 100 μm aluminum oxide (Al₂O₃) ceramic coating on the outer or inner ring, withstanding >1,000 V DC. Example codes: 6316/C3VL0241, 6320/C3VL0241.
• Hybrid ceramic bearings: silicon nitride (Si₃N₄) rolling elements replacing steel — providing complete electrical insulation with reduced friction. More expensive than INSOCOAT but longer-lived at high speeds.
• Grounding rings: installed on the motor shaft to discharge current before it passes through the bearing.

Large motor SRB

Motors above 500 kW typically use SRB at the drive end (DE) to accommodate heavy radial loads and misalignment, combined with DGBB at the non-drive end (NDE) for axial positioning. Example: SRB 22228 EK (DE) + DGBB 6228 C3 (NDE) for a 1,500 kW motor.

A thermal power plant in Quang Ninh province eliminated ID fan motor bearing failures — previously occurring 4 times per year — by replacing standard bearings with INSOCOAT combined with grounding rings. The additional investment of approximately 800 USD per motor saved over 50,000 USD per year in repair costs and lost generation.

Further reading: Electric motor bearings, Bearing lubrication, Ball bearing products.

Paper & Packaging — Dryer Cylinder, Press Roll, Calender

The paper and packaging industry requires bearings to operate continuously in high-humidity environments, at elevated temperatures (dryer cylinders up to 180°C), and under heavy nip loads between rolls. Each wide-format paper machine contains 40–100 rolls, each with two bearing positions — totaling 80–200 bearings requiring management (FAG, Paper machine bearing solutions).

Dryer cylinder — Heat-resistant SRB

Dryer cylinders charged with 5–8 bar steam reach surface temperatures of 120–180°C. SRB in the 22228, 22232, and 22236 range with C4 clearance (compensating thermal expansion) and brass cages (CA) are the standard selection. SNL or SDAF plummer block housings with labyrinth seals prevent condensate ingress.

Grease must withstand 180°C continuously — polyurea or PFPE-based formulations. Relubrication intervals of 500–1,000 hours depend on actual operating temperature.

Press section — Heavy-duty SRB

Press rolls operating at 80–120 kN/m nip pressure generate very high radial loads. SRB in the 231xx–232xx range with C3 clearance and EP (extreme pressure) grease meet the requirements. Some plants use self-aligning housings to compensate for machine frame deflection.

Calender roll — Higher precision bearings

Calender rolls (smoothing the paper surface) require lower runout — SRB in precision class P6 or CL7C (SKF). Operating speeds of 500–1,200 rpm with nip loads of 60–100 kN/m.

A packaging paper mill in Binh Duong province reduced web breaks by 35% after upgrading all dryer cylinder bearings to C4 clearance and increasing relubrication frequency from 2,000 hours to 800 hours.

Further reading: Bearing maintenance, SRB products.

Textile & Dyeing — High-Temperature Pumps, Corrosion Resistance

Vietnam's textile and dyeing sector operates bearings under three simultaneous challenges: high temperature (dyeing at 130°C), corrosive chemicals (alkali, acid, dye solutions), and high humidity (NTN, Textile industry bearing guide).

Dye bath circulation pumps

Pumps circulating dyeing solution at 100–130°C use DGBB 6305–6310 with double seals and fluorocarbon (PFPE) grease for chemical resistance. Stainless steel 316 pump shafts combined with mechanical seals prevent dye solution from reaching the bearing cavity.

Stenter frame

Stenters drying fabric at 160–200°C use heat-resistant bearings for the fabric transport chain and circulation fans. DGBB 6204–6208 with 200°C-rated grease and low-friction seals minimize friction-generated heat.

Spinning and high-speed weaving

Spinning spindles rotating at 10,000–25,000 rpm use small angular contact ball bearings (7200 series) or miniature deep groove ball bearings (62xx, 63xx). Requirements: high-speed grease, low noise (vibration group V1 or V2), and service life of 15,000–20,000 hours.

A textile plant in Dong Nai province reduced spindle bearing consumption by 30% after switching to synthetic ester grease and installing spinning room temperature control maintaining below 35°C.

Corrosion protection in dyeing and washing

Chemical vapor (NaOH, H₂O₂, disperse dyes) penetrating housings causes rapid corrosion. Solutions: stainless steel 440C bearings for light loads, ceramic-coated outer rings for medium loads, or polymer thermoplastic housings for the most aggressive environments.

Further reading: Electric motor bearings, Ball bearing products.

Cross-Industry Comparison

Each industry prioritizes different bearing attributes. The table below summarizes the primary requirement, dominant bearing type, and downtime cost for each sector:

Industrial Bearing Selection Principles

Regardless of sector, industrial bearing selection follows five steps:

Step 1 — Determine load and speed. Radial load (Fr), axial load (Fa), shock load factor (fd), and rotational speed (n) are the four mandatory input parameters. Calculate equivalent load P = X·Fr + Y·Fa per ISO 281 (ISO 281:2007, Rolling bearings — Dynamic load ratings).

Step 2 — Select bearing type. SRB for heavy load + misalignment, TRB for combined load + precise positioning, DGBB for light-to-medium load + high speed, ACB for very high speed + precision.

Step 3 — Determine clearance and fit. CN (normal) clearance for most applications, C3 for mild thermal expansion or tight inner ring fit, C4 for temperatures above 100°C or very tight fits. Shaft fit typically k5–m6 for rotating inner ring load, housing fit H7–J7.

Step 4 — Select lubrication. Grease for >90% of applications, oil for very high speed or very high temperature. Initial grease fill = 30–50% of bearing free volume. Relubrication interval calculated using tf = K·(14,000,000/(n·√d) − 4·d) hours (SKF relubrication formula).

Step 5 — Design sealing and protection. Contact seals for clean environments, labyrinth seals for dirty environments, labyrinth + grease purge for severely contaminated environments. Add vibration and temperature monitoring for critical equipment.

The Value of Correct Bearing Selection

Bearings represent less than 1% of equipment value yet cause over 50% of unplanned downtime in industrial plants. Selecting the correct bearing designation, clearance, lubrication, and sealing for the specific application can:

• Extend bearing service life 2–5 times compared to incorrect selection
• Reduce annual bearing maintenance costs by 30–60%
• Bring unplanned downtime to near zero with online monitoring

With high-quality European bearing supply at competitive pricing, Vietnamese plants can upgrade bearings without exceeding maintenance budgets. Contact us for complimentary technical consultation to identify the optimal bearing designation for each equipment position.