GRW Bearings from National Precision Bearing
Since 1942, GRW has been the technology leader for high-precision ball bearings, assemblies and accessories. They utilize state-of-the-art equipment and manufacturing processes. In 2015, Kaman Corporation purchased GRW.
They specialize in low friction and low noise miniature and instrument bearings for medical devices, dental equipment, drive systems and other industrial applications. Their bearings are available in metric and inch dimensions.
You can rely on GRW and National Precision Bearing to meet any requirements or challenges you may face.
GRW Products
Radial Deep Groove Ball Bearings
Single-row deep-groove ball bearings are suitable for use at both low and high speeds. They have the ability to absorb radial and axial forces. GRW deep grove bearings are available in chromium steel, for 100Cr6 bearing rings, they also offer the stainless martensitic anti-friction SS (X65Cr13) and SV (X30CrMoN15-1) roller bearing steels. Hybrid designs are also available where the balls are made of a ceramic material. GRW radial deep groove bearings are available in Inch and Metric Dimensions.
GRW standard deep-groove ball bearings are manufactured according to ISO or AFBMA standards.
Make sure to ask your National Precision sales person about GRW ball bearings.
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Spindle Ball Bearings
GRW spindle ball bearings are suitable for numerous applications, such as machine tools, requiring precision while carrying a high load capacity combined with high speed.
GRW spindle ball bearings are single-row angular contact ball bearings (separable ball bearings) with a nominal contact angle of 15° or 25°. They can be subjected to both radial and (in one direction) axial loads.
GRW spindle bearings are characterized by the following properties:
- Manufactured in grade P4(Abec 7) or better
- Rings are generally made of corrosion resistant SV30 high-grade steel
- Available with both steel or ceramic balls
- Machined solid retainers of fiber-reinforced phenolic resin or special materials
- 15 degree © or 25 degree (E) contact angle as standard
- Oil or grease lubrication
- Open and closed versions are available
- Available in light, medium or heavy pre-loads
Open spindle ball bearings
- Standard version with large balls and a solid retainer for high bearing capacity
- Bearing outer ring has one shoulder only. The increased height of the snap feature prevents bearing collapse.
- The solid retainer is guided on the outer ring with a low cross-section and is particularly well suited for oil injection lubrication
Closed spindle ball bearings
- The shields are non-contact resulting in no additional friction
- They have a narrow sealing gap for dust protection
- Recommended with grease lubrication for extended service life
- Same outer dimensions as the open spindle bearings
- This design might require smaller balls, which would result in a lower bearing capacity but higher axial stiffness and speed limit.
- Also can be purchased without closures as a high-speed version
Make sure to ask your National Precision sales person about GRW spindle bearings.
Duplex Bearings
GRW Duplex bearings are two matched bearings, which provide the following bearing characteristics:
- Accurate bearing positioning in radial and axial directions
- Higher load capacity compared to a single bearing
- Matched sets
The matching of the bearings is achieved by loading each single bearing with a desired preload and then relieving the inner and/or outer rings until the surfaces of both rings are flush with each other. Two bearings machined in this way are assembled according to their markings and the instruction on the package, and loaded axially with the specified or required force. Depending on the matching used, either the inner rings or the outer rings, or even both rings are clamped together. The ball bearings must be mounted in accordance with the installation instructions on the packaging labels or the marks on the ball bearings.
The following types of Duplex assembly for deep groove radial ball bearings and spindle bearings are available:
- O arrangement: Back to back (pairing type -1 or DB with spindle bearings)
- X arrangement: Face to face (pairing type -2 or DF with spindle bearings
- Tandem arrangement (pairing type -3 or DT with spindle bearing)
- Universal (pairing type -4 or DU with spindle bearings)
Make sure to ask your National Precision sales person about GRW duplexed bearings.
Axial Deep Groove Ball Bearings
GRW bearings for customized applications
GRW axial deep groove ball bearings have axially asymmetric races. Axial deep grove ball bearings are ideally suited for special applications, or unique, customized specifications.
As axial bearings, they are used exclusively for axial loads. They are not suitable for radial loads or for use in applications where there may be misalignment. Of the groove ball bearings, these are specialized bearings and depend on having flush and rectangular seats.
The single-sided acting GRW axial deep groove ball bearings consist of:
- A plane washer with a race
- A flat hosing with a race and
- The set if balls together with a sheet steel cage
Due to their design, axial deep groove ball bearings are not self-locking. This provides the advantage of separately installing and removing the shaft and housing washers.
GRW can offer axial deep groove ball bearings in chromium steel or in stainless martensitic roller bearing steel.
