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If you are replacing a failed motor bearing, matching only the 95 × 200 × 45 mm dimensions is not enough. The buyer also needs to confirm the cage, radial clearance and location of the insulating coating. Otherwise, an ordinary 6319 may fit the shaft and housing but remove the electrical protection specified for the motor.
This matters when the removed bearing has a fluted raceway. The bearing may have carried the mechanical load correctly and still failed because electrical current passed through the rolling contacts. Noise and vibration often appear first; by the time the bearing is removed, the raceway may show pitting or a distinct washboard pattern.
SKF 6319 M/C3VL0241 is specified to address more than one requirement. It combines a 6319 single-row deep groove ball bearing with a machined brass cage, greater-than-Normal radial clearance and an electrically insulating coating on the outer ring from the insulated-bearing family. Leave out any one of those suffixes and the quotation can become a different bearing.
Before approving a quotation, check that the supplier confirms all four elements in writing:
| Order requirement | What the quotation should confirm |
|---|---|
| 6319 | Deep groove ball bearing, 95 × 200 × 45 mm |
| M | Machined brass cage, ball centred |
| C3 | Radial internal clearance greater than Normal |
| VL0241 | INSOCOAT insulation on the outer-ring external surfaces |
Editorial illustration: an insulated motor-bearing inspection scene. Confirm the supplied product from its complete marking and documentation.
The base 6319 is a metric single-row deep groove ball bearing. The SKF 6319 M/C3VL0241 product keeps those boundary dimensions while adding the specified cage, clearance and insulation features. This bearing type is designed primarily for radial load and can also accommodate axial load in both directions within the limits of the application. It has a cylindrical bore and an open bearing arrangement unless another closure suffix is specified.
The verified boundary dimensions for the 6319 size are:
| Item | Value |
|---|---|
| Bore diameter, d | 95 mm |
| Outside diameter, D | 200 mm |
| Width, B | 45 mm |
SKF catalogue data for the base 6319 size lists a basic dynamic load rating of 159 kN and a basic static load rating of 118 kN. These catalogue values are not a machine service-life guarantee. Actual life depends on load, speed, fit, lubrication, temperature, contamination, shaft voltage and mounting accuracy.
In SKF rolling-bearing nomenclature, M identifies a machined brass cage centred on the rolling elements. A machined brass cage is different from the standard pressed-steel cage found in many common deep groove ball bearings.
The cage suffix must remain on the purchase request when the motor or machine specification calls for it. Changing the cage can affect mass, speed behaviour, lubrication demand and performance under vibration or acceleration. It should not be removed merely because an ordinary 6319 has the same boundary dimensions.
C3 means that the bearing's radial internal clearance is greater than the SKF Normal clearance range before mounting. It does not mean “precision class 3,” and it is not automatically an upgrade for every application.
The effective clearance changes after the bearing is mounted and reaches operating temperature. A tight interference fit can reduce internal clearance. A hot inner ring and cooler outer ring can reduce it further. Motor designers may therefore specify C3 to obtain the required operating clearance after these effects are considered.
Substituting Normal clearance, C4 or another class without reviewing the shaft fit, housing fit, speed and temperature can cause heat, noise or reduced bearing life. Preserve the specified clearance unless the motor manufacturer or responsible engineer approves a change.
Technical illustration: VL0241 identifies outer-ring insulation. The image is not an official SKF product drawing.
VL0241 identifies SKF's standard INSOCOAT electrically insulating coating on the external surfaces of the outer ring. The coating integrates the insulating function into the bearing and helps interrupt the path of damaging electrical current through the rolling contacts.
SKF's current INSOCOAT information lists its standard VL0241 outer-ring coating with a minimum 3,000 V DC breakdown voltage and minimum electrical resistance of 200 MΩ under the specified test conditions of temperature no higher than 40°C and relative humidity no higher than 60%. These are coating specification values, not permission to expose the installed bearing to an arbitrary continuous voltage.
The suffix should not be shortened to VL024 or confused with VL2071. SKF identifies VL2071 as an insulating coating on the inner-ring surfaces. Outer- and inner-ring coatings serve the same general purpose but are not the same product configuration.
Voltage can build between the shaft and housing in electric motors and generators. If the lubricant film can no longer insulate the rolling contact, current may discharge through the bearing. Variable-frequency drives, high switching frequencies, grounding condition and machine geometry can influence this risk.
Repeated discharge can melt microscopic points on the raceway. Over time, the surface damage can become fluting. Metal particles and electrical stress can also degrade the lubricant, increasing noise and temperature.
An insulated bearing is one part of the protection strategy. Grounding, cabling, drive settings, shaft-grounding devices and the bearing arrangement should be reviewed at system level. Installing one insulated bearing in the wrong position may not solve the current path.
This size and configuration may be considered for medium and large electric motors, generators and other rotating electrical equipment where a 95 × 200 × 45 mm deep groove ball bearing, C3 clearance, machined brass cage and outer-ring insulation are specified.
Do not select it from the application description alone. The non-drive end and drive end can use different bearing types. One position may need axial location while another must accommodate thermal expansion. Some motors use a cylindrical roller bearing at one end and a deep groove ball bearing at the other.
Before replacement, confirm the motor manufacturer's bearing arrangement, shaft and housing fits, original marking and insulation location.
Not when electrical insulation is required. An ordinary 6319 M/C3 may match the main dimensions, cage and clearance, but it does not include the VL0241 outer-ring insulating coating. Installing it would remove a specified electrical protection feature.
Similarly, 6319/C3VL0241 should not automatically replace 6319 M/C3VL0241 because the missing M indicates a different cage configuration. A buyer should compare the complete designation, not search only for 6319.
The coated outer-ring surfaces need careful handling. Do not strike, scratch or clamp the coating. Keep the bearing in its packaging until the mounting area is clean. Use suitable equipment and apply mounting force through the ring being fitted rather than through the rolling elements.
Editorial illustration: inspect the coating, fits and bearing position before mounting.
Check:
Bearing and package marking against the purchase order
Coating condition around the outer ring and side faces
Shaft and housing dimensions, roundness and surface condition
Shoulder geometry and fillet clearance
Radial clearance requirement and fit
Lubricant type, quantity and compatibility
Motor grounding and the intended insulated-bearing position
After installation, establish baseline vibration, noise and temperature. If the previous bearing showed electrical damage, confirm that the wider electrical-current problem has also been investigated.
A useful enquiry can be concise:
Please quote SKF 6319 M/C3VL0241, quantity __ pieces, for an electric motor. Destination: __. Please confirm the complete designation, outer-ring INSOCOAT configuration, current availability and traceability documents. Motor nameplate and existing bearing photographs are attached.
For a faster comparison, also ask the supplier to state the manufacturer, country of origin shown on the offered product, lead time, packaging condition and which traceability documents can be supplied. These points should appear in the quotation rather than being assumed from a stock photograph.
State clearly whether only SKF is acceptable or whether a technically reviewed alternative may be proposed. If alternatives are permitted, compare the bearing type, 95 × 200 × 45 mm dimensions, cage, C3 clearance, insulation location and electrical specification. “6319 insulated bearing” is not a complete substitution proposal.
The designation does not contain a seal or shield suffix. Buyers should not assume that it is grease-filled and sealed. Confirm the motor's lubrication arrangement and the supplied product configuration.
No. VL0241 describes an insulating coating on the outer-ring surfaces of a conventional rolling bearing. A hybrid bearing normally uses ceramic rolling elements. Both approaches can address electrical-current risks, but they have different construction and application considerations.
Not without technical approval. VL0241 is associated with outer-ring coating, while VL2071 identifies inner-ring coating. The machine design, bearing size and current path determine the appropriate option.
C3 provides greater initial radial internal clearance than Normal. It may be specified to account for clearance reduction caused by interference fits and operating temperature. It should still be checked against the actual motor design.
Send the full designation, quantity, destination, motor nameplate and clear photographs of the existing bearing and package. New customers may contact FONKIN BEARING through WhatsApp at +86-187-5155-1686 or email fonkin-industries@188.com.
SKF 6319 M/C3VL0241 should be purchased as a complete technical designation. 6319 defines the deep groove ball bearing size, M specifies a machined brass cage, C3 specifies greater-than-Normal radial internal clearance, and VL0241 specifies an electrically insulating coating on the outer ring. Removing any of these elements changes the request.
FONKIN BEARING can review motor-bearing lists, markings and application information before quotation. For the fastest response, send the complete bearing code, quantity, destination and motor details, and confirm whether only the requested SKF configuration is acceptable.
Request a checked quotation: send the complete marking, quantity, destination country, required delivery date and photographs of the bearing, package and motor nameplate. WhatsApp: +86-187-5155-1686 · Email: fonkin-industries@188.com · Send an enquiry
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