In a cylindrical roller bearing (CRB), the rollers carry radial load between two raceways. The number of rollers you can fit — and how they are kept in place — decides almost everything about the bearing's behaviour. Remove the cage and you fit the maximum number of rollers. That one change trades speed for load in a very predictable way.
1. What is a full-complement (non-cage) cylindrical roller bearing?
A full-complement CRB fills the space between the inner and outer race with the maximum possible count of rollers, with no cage (separator) between them. Because every millimetre of space holds a roller:
- Highest radial load capacity for a given bore and outside diameter.
- Very high rigidity — minimal elastic deformation under load.
- Smaller radial section — more rollers in the same envelope, saving axial installation space.
- Trade-off: without a cage, adjacent rollers touch and slide against each other at speed, generating heat. So the allowable speed is much lower than a caged equivalent.
2. What is a caged cylindrical roller bearing?
A caged CRB uses a separator to space and guide each roller. There are fewer rollers than a full-complement design of the same size, but each roller runs in a positively located pocket:
- Lower friction and higher allowable speed — rollers do not collide.
- Better for high-speed spindle, gearbox and motor duty.
- Lower radial capacity than full complement at the same envelope (fewer rollers share the load).
3. Side-by-side comparison
| Criterion | Full Complement (no cage) | Caged (separator) |
|---|---|---|
| Radial load capacity (same size) | Highest | Lower (fewer rollers) |
| Axial load capability | None (radial only)* | None, except NJ/NUP limited axial* |
| Allowable speed | Low (~30–50% of caged) | High |
| Rigidity | Very high | High |
| Radial section / envelope | Smaller (space saving) | Larger |
| Heat at speed | Higher (rollers rub) | Lower |
| Roller guidance | By each other (collision) | By cage (positive) |
| Typical duty | Low-speed, heavy, shock load | High-speed, smooth |
*Cylindrical roller bearings are fundamentally radial bearings. For combined radial + axial loads, use an NJ/NUP design (limited axial) or a different type (tapered / spherical / angular-contact).
4. Capacity & speed at a glance
Approximate, normalised to the caged design of the same size. Exact figures depend on series, lubrication and clearance.
Radial load capacity (higher = better)
Allowable speed (higher = better)
5. When to choose full complement (FAB model)
Where it belongs: crushers, ball mills, rolling stands, hoists, conveyors, winches, heavy/slow gearboxes, slewing and port machinery, and some wind-turbine main shafts. Anything slow, heavy and shock-loaded is full-complement territory.
6. When to choose caged
For applications dominated by speed and smoothness — electric motors, pumps, machine-tool spindles, high-speed gearboxes, and anywhere friction heat would otherwise limit life. Here the cage pays for itself many times over.
7. How to select a full-complement bearing (crusher checklist)
- Load: determine radial load — both dynamic (running) and static — and apply a shock factor for crusher / impact duty (often 1.5–2.5×).
- Speed: compute actual rpm. If it is below ~40–50% of the caged bearing's limiting speed, full complement is viable.
- Envelope: measure shaft diameter (bore) and the radial space available. Full complement's smaller section is an advantage in tight housings.
- Locating vs non-locating: pick the series — N / NU (non-locating, free axial), NJ / NUP (limited axial location), or full-complement NCF / NJG.
- Precision & clearance: specify P0/P6 and the right internal clearance for your temperature and fit.
- Lubrication: at low speed, full complement needs ample grease (or oil bath); ensure the housing supports it.
8. RAYSDE full-complement offering
Full-complement cylindrical roller bearings are our most-asked, most-specialised line — the one we are happy to engineer around your drawing rather than pull from a catalogue. Standard sizes: MOQ 300 sets, lead time 15–20 days; non-standard: MOQ 50 sets, 30–45 days. Full specs on the full-complement landing page →
9. FAQ
Can a full-complement bearing take axial load?
No — cylindrical rollers are radial-only. For light axial location use NJ/NUP; for real combined loads choose tapered, spherical or angular-contact bearings instead.
Why is the speed limit so much lower?
Without a cage, neighbouring rollers contact and slide as they pass the load zone, creating friction and heat. A cage keeps them apart so they roll cleanly.
Is full complement simply "stronger"?
Stronger in radial load and rigidity, yes. But not faster — and it will not outlive a caged bearing in a high-speed application. Match the design to the duty.
Do you make double-row full complement?
Yes — single and double row, including SL/RSL type, for very high radial stiffness in compact spaces.
Download the full technical whitepaper (PDF)
The printable version adds the dimension tables, load-curve plots and a one-page selection worksheet. We'll email it to you.