NAK Sealing Technologies / NAK Radial Oil Seals and Shaft Sealing Solutions

NAK Sealing Technologies / NAK is Taiwan's largest manufacturer of industrial oil seals, rotary shaft seals, and hydraulic packings. Engineered sealing solutions for speed reducers, pumps, and mobile machinery.

NAK V-Ring Shaft Seals (Types VA, VS, VL)

NAK elastomeric V-rings mount directly onto rotating shafts with an interference fit, sealing perpendicularly against stationary counter faces. The VA 31x39x4.7/7.5 NBR profile keeps external slurry, metal dust, and moisture away from high-speed precision bearing assemblies.

Standard profiles VA, VS, and VL accommodating shaft diameters from 2.7 to 2020 mm
Proprietary NBR, FKM, and silicone compounds operating from -40 deg C to +200 deg C
Low rotational friction dynamics maintaining sealing integrity under axial runout
Durable dynamic barrier protecting drive motor bearings against abrasive slurry

NAK Rubber OD Radial Oil Seals (Types SC, TC, VC, KC)

NAK rubber-covered outer diameter oil seals provide dependable static sealing within housing bores showing high thermal expansion or surface roughness. Dual-lip geometries in TC and KC profiles feature a secondary exclusion lip that blocks abrasive particulate in gear reducers.

Fully rubber-covered outer diameter eliminates bore corrosion and fluid seepage
Carbon steel garter spring maintains consistent radial contact load along shafts
Secondary dust lip geometry prevents particulate ingress in industrial gearboxes
Full compatibility with mineral lubricants, synthetic gear oils, and greases

NAK Metal OD Radial Oil Seals (Types SB, TB, VB, KB)

NAK precision ground metal outer diameter shaft seals ensure rigid press-fit retention in heavy industrial housings subject to vibration. The sturdy steel body prevents axial dislocation under pressure spikes, serving reliably in heavy extrusion gear drives and rolling mill gearboxes.

Precision ground metal outer body delivers tight press-fit retention in bores
High structural rigidity preventing seal pop-out under intermittent pressure
TB and KB profiles with hydrodynamic pumping ribs for directional oil return
Proven durability in industrial gear drives, rolling mills, and heavy pumps

NAK Metal Shrouded Axial Face Seals (Types RE, RE1)

NAK Type RE axial face seals integrate an elastomeric V-lip with a protective outer steel shroud for extreme duty environments. Rotating with the shaft, the assembly repels coarse slurry, agricultural debris, and mining abrasives through dynamic centrifugal deflection forces.

Rigid outer steel shroud shields the elastomeric lip from coarse rock debris
Shaft-driven rotation creates a centrifugal effect that slings mud and liquid
Axial sealing against counter flanges in mining drives and track roller hubs
Exceptional impact endurance under rugged construction equipment conditions

NAK Hydraulic Piston and Rod Seals (Types UOP, HPO, HRO)

NAK hydraulic cylinder packings utilize advanced polyurethane and nitrile elastomers engineered with asymmetric sealing profiles. Specialized piston seals UOP and rod packings HRO maintain low breakout friction and superior fluid barrier integrity at pressures up to 40 MPa.

Asymmetric dynamic lip geometry delivers optimized contact stress profiles
Tough polyurethane formulations resist extrusion under high hydraulic surge
Operating pressure capability up to 400 bar across variable stroke speeds
Standard fitment for industrial press cylinders and earthmoving equipment

NAK Bonded Washers and Wiper Seals (Types WS, KDS, VA1)

NAK bonded washers WS and KDS integrate a zinc-plated steel outer ring with an elastomer lip to seal threaded fluid fittings under high torque. Companion wiper rings VA1 through VA5 clear abrasive dirt, moisture, and road grit from reciprocating cylinder rods with low drag.

Permanently bonded rubber-to-metal structure prevents lip roll-over or creep
Static sealing for pipe unions, drain plugs, and manifold ports up to 70 MPa
Dynamic wiper lips scrape away encrusted dirt, ice, and industrial debris
Prolongs hydraulic fluid life by blocking particulate contamination at rods

DIN 3760 Radial Shaft Seal Design Geometries

NAK Sealing Technologies / NAK manufactures radial lip seals across basic designs A, B, and C adhering to DIN 3760 and ISO 6194 industrial dimensions.

The Type C architecture (profiles SC, TC, VC, KC) features a rubber-covered outer diameter providing dependable static sealing within housing bores showing high thermal expansion.

The Type B series (profiles SB, TB, VB, KB) incorporates a precision ground metal outer shell for rigid press-fit retention in heavy industrial housings subject to vibration. The Type A series provides double metal reinforcing rings for demanding rolling mill and extruder gear drive duties.

Selecting the correct outer shell ensures complete static retention and bore leakage prevention.

Elastomeric Compound Selection for Temperature and Fluid Media

The operational service life of NAK Sealing Technologies / NAK shaft seals depends upon elastomeric compatibility with lubricating fluids and ambient operating temperatures. Standard nitrile rubber (NBR) operates reliably from -40 to +100 deg C in mineral oils, greases, and water.

Fluoroelastomer (FKM Viton) withstands continuous exposure from -20 to +200 deg C, retaining resilience in synthetic gear oils, hydrocarbons, and aggressive fluid additives.

Polyacrylate rubber (ACM) serves in hot transmission assemblies up to +150 deg C, while ethylene propylene diene monomer (EPDM) is specified exclusively for glycol-based brake fluids, phosphate esters, and industrial steam.

NAK VA V-Ring Mounting and Operational Principles

NAK Sealing Technologies / NAK VA series axial face seals mount directly onto the rotating shaft with an interference fit and rotate with it, sealing perpendicularly against a stationary counter wall.

Unlike radial lip seals, VA, VS, and VL profiles do not require hardened or ground shaft counter-surfaces and tolerate angular misalignment up to one degree.

As the shaft rotates, centrifugal force slings liquid slurry, abrasive grit, and dust away from the seal lip, establishing a dynamic protective barrier for bearing units.

When mounting the VA 31x39x4.7/7.5 NBR seal, maintaining the specified axial distance to the counter face prevents excessive friction and premature lip wear.

Exclusion Lip Geometries and Hydrodynamic Helix Ribs

For contaminated equipment environments, NAK Sealing Technologies / NAK provides dual-lip shaft seals with secondary exclusion lips (TC, KC, TB, KB). The dust lip protects the primary sealing lip against abrasive particulate, while the intermediate cavity holds lubricating grease.

For high-speed gearbox shafts, NAK incorporates patented Helix hydrodynamic pumping ribs (clockwise R, counterclockwise L, or bidirectional W).

During shaft rotation, the micro-pattern pumps escaping fluid back into the lubricating reservoir, substantially lowering operational temperatures at the contact interface and extending lip endurance.

Press-Fitting Guidelines and Shaft Counterface Preparation

Optimum operational endurance of NAK Sealing Technologies / NAK seals requires strict adherence to installation guidelines and counterface standards. Shaft surface finish at the contact band must maintain Ra 0.2 to 0.8 micrometers with a surface hardness of at least 45 to 55 HRC.

Plunge grinding without spiral lead is mandatory to prevent fluid pumping past the seal lip. Pressing the seal into the housing bore requires a dedicated installation tool applying uniform pressure onto the outer shell without tilting.

When passing the seal over keyways, splines, or threads, protective assembly thimbles prevent micro-cuts to the delicate elastomeric lip.

Storage Standards for Elastomeric Seals to Prevent Aging

Elastomeric seals from NAK Sealing Technologies / NAK require storage compliance with DIN 7716 guidelines to prevent premature thermal, ozone, or UV degradation.

Products must remain in their original sealed packaging in a dry, ventilated room at +15 to +25 deg C with relative humidity below 65 percent. Direct sunlight, artificial ultraviolet radiation, and proximity to ozone-generating equipment (electric motors, welders) must be avoided.

Seals must be stored in a relaxed state without hanging on pins, hooks, or wires, preventing static stresses that induce permanent elastomeric distortion.

NAK Sealing Technologies / NAK and model names are trademarks of their respective owners and are used only to identify the equipment for which we source parts. SpareX is not an official dealer, distributor or representative of NAK Sealing Technologies / NAK and is not affiliated with the trademark owner. Origin, documents and warranty are stated for each item in the quotation.