What Is a Cylindrical Roller Thrust Bearing? Construction, Load Ratings & Applications

Put a cylindrical roller thrust bearing next to a ball thrust bearing built for the same 30 mm shaft, and the difference shows up immediately: the roller version is about 29% narrower — 11 mm across instead of 15.5 mm.

It also carries roughly 69% more static load. That trade — a thinner axial section in exchange for higher one-directional thrust capacity — is the entire reason this bearing type exists as a separate category from the ball thrust bearings most people think of first.

What a Cylindrical Roller Thrust Bearing Can't Do

Start with the limitation, because it's the one detail that determines whether this bearing is even the right choice: cylindrical roller thrust bearings support heavy axial load and peak loads in one direction, but not radial load — that's a direct statement from the product line's own category description, not a general rule of thumb.

There's no raceway curvature built into the geometry to react to a sideways force. If your shaft carries both axial and radial load, the radial component has to be carried by a separate bearing entirely.

Cylindrical Roller Thrust Bearing Construction: Three Parts

Unlike a sealed ball bearing, a cylindrical roller thrust bearing is specified — and often ordered — as three separate pieces: a shaft washer, a housing washer, and a roller-and-cage thrust assembly that rides between them.

Catalog part numbers make this visible directly in the prefix: WS for the shaft washer, GS or OW for the housing washer, and K for the roller-and-cage assembly. Large sizes sometimes use IW/OW instead of WS/GS — both mean the same thing, inner washer and outer washer.

Splitting the bearing into three parts isn't just a labeling convention. It lets one roller-and-cage assembly pair with different washer types — flat washers for a fixed installation, self-aligning washers where the mounting expects some shaft misalignment — which is why catalogs list washers and roller-and-cage assemblies as separate line items instead of one fixed unit.

There's also a naming pattern worth knowing before you even open a spec sheet: part numbers ending in "TN" use a glass-fibre-reinforced PA66 cage, while part numbers ending in "M" use a machined brass cage. That's consistent across every size checked in this catalog, from the 17 mm-bore 81103 TN up through the 100 mm-bore 81120 TN (both PA66), switching to brass at the 200 mm-bore 81140 M and staying brass all the way to the 1,000 mm-bore 811/1000 M.

Cylindrical Roller Thrust Bearing Load Ratings by Size

The 811/812 series spans nearly a 60-fold range in bore diameter within a single catalog family, and the numbers scale accordingly.

Two patterns stand out. First, the static-to-dynamic ratio widens with size — 2.6:1 at the 17 mm bore, climbing to 6.8:1 at the 1,000 mm bore — the same pattern seen in tapered roller thrust bearings, suggesting it's a general feature of how these fatigue-based ratings scale, not something unique to one bearing type.

Second, maximum speed drops by a factor of roughly 28 across the range, from 8,500 rpm at the smallest bore down to 300 rpm at the largest — a reminder that a bearing rated for enormous static load isn't necessarily a high-speed component.

Browse current cylindrical roller thrust bearing part numbers for size-by-size specifications.

Same-Bore Comparison: Cylindrical Roller vs. Ball Thrust

At an identical 30 mm bore, the two bearing types split the difference between compact section height and raw capacity.

At the same bore, the cylindrical roller version is thinner, carries more load in both static and dynamic terms, and — in this specific pair — even edges out the ball version on maximum speed. The ball thrust bearing's advantage shows up elsewhere: lower friction at very light loads and tolerance for slight misalignment via aligning-seat washer variants, neither of which shows up in a load-rating table.

For where cylindrical roller thrust bearings sit against the heavier-duty tapered roller design, see What Is a Tapered Roller Thrust Bearing? For the category overview, see What Is a Thrust Bearing?

Cylindrical Roller Thrust Bearing Applications

The combination of high one-directional thrust capacity and minimal axial footprint makes cylindrical roller thrust bearings a common specification in machine tool spindles, gearboxes, and other equipment where axial installation space is tight but the thrust load running through that space isn't small.

This is general engineering practice rather than a claim tied to a specific catalog citation — unlike the TTHD tapered roller construction, this product line's category description doesn't name specific end-use industries.

Frequently Asked Questions

What actually happens if this bearing sees radial load in service?

Because the rollers only make line contact along a flat washer surface, a radial force pushes the rollers to skew rather than roll evenly. That uneven, edge-loaded contact concentrates stress at the roller ends and accelerates wear dramatically.

Bearing life in a radially loaded installation typically drops far faster than the load-rating numbers would suggest, because those numbers assume pure axial loading.

How is this different from a needle roller thrust bearing?

Same basic layout — rollers between two flat washers — but a needle roller thrust bearing uses much smaller-diameter rollers, which shrinks the axial section further at the cost of load capacity.

Choose needle roller thrust when axial space is the tightest constraint you have. Choose cylindrical roller thrust when you need more load capacity and can spare a few extra millimeters of width.

Do I need to buy the washers and the roller-and-cage assembly separately?

Usually yes, and that's intentional — it lets you pair one roller-and-cage assembly with the washer type that fits your mounting: flat washers for a fixed installation, self-aligning washers where you expect some shaft misalignment.

What clearance or preload does installation need?

Standard practice is a small amount of running clearance rather than preload, since the bearing has no radial capacity to fall back on if the rollers are pinched too tight axially.

Manufacturer mounting guidance for the specific series should set the exact figure — get it wrong and you either lose load capacity or overheat the bearing.

Should I override the standard TN/M cage material choice for my application?

Usually not — the catalog's default cage material per size already reflects the load and speed that size is built for. Glass-fibre PA66 on smaller, faster-turning sizes runs cooler and lighter than steel would; machined brass on larger, slower sizes holds up to the higher unit loads those bearings see.

The cases where you'd deviate are unusual: extreme ambient temperature, exposure to solvents that attack PA66, or a speed requirement well outside the standard rating for that bore.

Why does the maximum speed rating drop so much between small and large sizes?

Larger rollers moving through the same rotational speed sweep a larger raceway circumference, which generates more heat and centrifugal loading per revolution.

The 28-fold drop in max speed across this series — 8,500 rpm at 17 mm bore down to 300 rpm at 1,000 mm bore — reflects that physical reality rather than a conservative engineering margin that could be pushed higher with a better cage or lubricant.