Bearing puller guide: 2-arm or 3-arm, which one?
A bearing puller removes ball bearings, pulleys and gears from a shaft without hammering and without damage. This guide explains how to choose by arm count, how to size the jaw span and reach, and when to use an internal or external grip.
View pullers2-arm or 3-arm - what is the difference?
The number of arms decides how evenly the pulling force spreads across the component. A 2-arm puller is slim and fits into tight spaces or behind spokes, while a 3-arm puller centres the part better and is less likely to tilt.
For round, freely accessible parts such as pulleys, gears or bearings on a shaft, the 3-arm is the safe choice because the load sits symmetrically. The 2-arm wins when only two opposing grip points are reachable or a web is in the way.
- 2-arm: slim, fits narrow gaps and reaches behind webs or spokes.
- 3-arm: self-centring, spreads the load evenly, less tilting.
- Self-centring models hold the arms parallel while you set them.
- Both types are available with a hydraulic spindle for high forces.
How do I work out jaw span and reach?
A puller only fits if the arms hook securely behind the part. The two key figures are the jaw span (the diameter the opened arms enclose) and the reach (how far the hook tips extend behind the part).
Measure the outer diameter of the bearing or hub and choose a puller whose span covers that value near the middle of its range, not at the outermost limit. That keeps a reserve and holds the arms as close to perpendicular to the shaft as possible.
Internal or external grip - when to use which?
The difference is where the arms grip. With an external grip the hooks wrap around the part from the outside - the normal case for bearings on a shaft, pulleys and gears.
With an internal grip the reversed arms reach into a bore or blind hole and pull the part out from inside. This is needed when a bearing sits in a housing and the outer ring is not accessible. Many pullers switch between both modes by flipping or reversing the arms.
- External grip: standard for bearings, pulleys and hubs on a shaft.
- Internal grip: for bearings in a housing or blind holes, arms grip outward.
- A back plate or separator protects delicate inner rings.
- Always apply force through the tight ring, never through balls or rollers.
Frequently asked questions
2-arm or 3-arm - which is better?
The 3-arm centres better and tilts less, ideal for round, freely accessible parts. The 2-arm is slimmer and fits into tight spaces or behind webs. Both are also available with a hydraulic spindle for high forces.
How do I pick the right size?
Measure the outer diameter of the part and choose a puller whose span covers that value near the middle of its range. The reach of the arms must be greater than the width of the part so the hooks do not slip off.
When do I need an internal-grip puller?
When a bearing sits in a housing or blind hole and the outer ring is not accessible. The arms are reversed and reach into the bore to draw the part out from inside.
How do I remove a bearing without damage?
Always run the pulling force through the tightly seated ring, never through the balls or rollers. A back plate or separator adds protection, and a little penetrating oil eases the release.
Looking for the right bearing puller?
We stock 2- and 3-arm pullers, internal and external grip, and hydraulic sets in all common spans - selected with advice for your component.
Wide range
2- and 3-arm, internal and external grip, mechanical and hydraulic.
Component-friendly
The right span prevents tilting and slipping.
Correctly sized
Jaw span and reach matched to your bearing.
Expert advice
Our specialists help you pick the right size.