Last updated: 11 August 2026
A Bosch Rexroth 4WE model code has six segments, and five of them must match exactly for a replacement valve to work. The sixth, the spool symbol, decides what your machine does when the solenoid is not energised. This guide explains what each segment means, which ones you can read off the nameplate yourself, and which ones need confirming before you order.
If a directional valve has failed on a press, a clamp circuit or a hydraulic power unit, the nameplate is the fastest route to the right replacement. It is also the most common place ordering errors start, because two valves whose codes differ by a single character can hold a cylinder in place or drop it.
What a 4WE model code actually tells you
The code is a configuration string, not a part number. It describes the valve rather than identifying one catalogue item, which is why the same code can appear with different Rexroth material numbers. Read it left to right and each segment narrows the valve down further.
4WE 6 J 6X / EG24 N9K4
A direct-operated, solenoid-actuated four-way directional spool valve, NG6 interface, J spool, component series 6X, with a 24 V solenoid and an N9K4 connector arrangement.
Why the mounting pattern is standard but the valve is not
NG6 and NG10 refer to ISO 4401 interface sizes, so the bolt pattern and port positions are standardised across manufacturers. That is genuinely useful: a valve will physically bolt to the subplate. It is also the trap. A valve that mounts correctly can still be the wrong valve, because the spool symbol, the solenoid voltage and the connector are not covered by the interface standard.
This is the reason a valve can arrive, fit, and still leave the machine down. The three things ISO 4401 does not standardise are exactly the three things most likely to differ between a failed valve and its replacement.
The spool symbol is the character that decides machine behaviour
The letter after the nominal size defines how P, T, A and B connect in each switching position. For three-position valves it also defines the neutral position, which is the state the valve returns to when the solenoid is de-energised or power is lost.
That neutral behaviour is a functional and safety decision, not a preference. A spool that blocks all ports in neutral holds a cylinder in position. A spool that connects the actuator ports to tank lets it move. Substituting one for the other changes what happens to a suspended load when the machine stops, so the spool letter should be matched exactly or confirmed against the Rexroth data sheet before ordering.
We do not publish spool function tables from memory. Confirm the symbol in Bosch Rexroth data sheet RE 23178, or send us a photo of the nameplate and a Charlotte application engineer will identify the valve and the current equivalent.
4WE6 spool codes we stock
These are the NG6 spool variants that come up most often in our catalogue. Each links to live availability, where stocked.
4WE6 or 4WE10: telling the two apart
The nominal size is the second number in the code and it is the fastest way to narrow a search. NG6 valves are the smaller, direct-operated size used on most clamp, index and auxiliary circuits. NG10 valves handle higher flow and appear on main circuits and larger power units.
Ratings vary by spool and series, so take them from the Rexroth data sheet that matches your exact code rather than from a family-wide figure. If the valve is part of a system we can see, our industrial hydraulics team can size the replacement against the circuit rather than the nameplate alone.
Repair or replace a failed 4WE valve
Directional spool valves usually fail in one of three ways, and only one of them means the valve itself is scrap. Checking which one you have takes a few minutes and often avoids an unnecessary order.
- Solenoid or coil failure. The valve does not shift, but shifts normally when the spool is pushed manually with the override pin. The coil is frequently replaceable on its own.
- Connector, cable or supply fault. The coil is intact and the fault is upstream. This is an electrical problem, not a hydraulic one, and it is the most commonly misdiagnosed of the three.
- Spool sticking or contamination. Sluggish or partial shifting, often accompanied by fluid that is past its cleanliness target. Replacing the valve without addressing the fluid tends to produce a repeat failure.
Livingston & Haven repairs Bosch Rexroth and Indramat hydraulic and drive units in house, so we can evaluate a unit rather than default to a new sale. See Rexroth and Indramat repair services, or, if the valve sits on a unit we built or can rebuild, custom hydraulic power units.
What you need, and where to go
Common questions
What does 4WE mean on a Rexroth valve?
It denotes a four-way directional spool valve with solenoid actuation. The 4 is the number of main working ports, P, T, A and B. WE indicates a directional spool valve operated electrically by solenoid. Pilot-operated versions of the same family carry WEH, and hydraulically actuated versions carry WH.
What does 6X mean in a Rexroth 4WE6 code?
6X is the component series. The series number governs which mounting and connection dimensions are interchangeable between valves, so two valves with different series numbers are not automatically substitutable even when the rest of the code matches. Confirm the series against the Rexroth data sheet for your valve before ordering a replacement.
Are 4WE6 and 4WE10 interchangeable?
No. They are different nominal sizes with different ISO 4401 mounting interfaces, NG6 and NG10 respectively. They will not fit the same subplate. The nominal size is the second number in the model code and is the first thing to match.
What does EG24N9K4 mean at the end of a 4WE code?
It is the solenoid and connector block, covering the supply type, the nominal voltage, the connector arrangement and the sealing variant. The 24 refers to a 24 V nominal solenoid. Because the connector and sealing details are encoded here rather than in the interface standard, this block should be matched exactly. Confirm it in the Rexroth data sheet or send us the nameplate.
Can a Bosch Rexroth 4WE valve be repaired?
Often, yes. Solenoid coil failures and connector faults are frequently resolved without replacing the valve body, and spool sticking caused by contamination sometimes clears once the fluid is brought back within its cleanliness target. Livingston & Haven repairs Bosch Rexroth and Indramat units in house and can advise whether repair or replacement is the better route for your unit.
Where do I find the Rexroth 4WE6 data sheet?
The relevant Bosch Rexroth document for direct-operated NG6 directional spool valves is RE 23178. Use the revision that matches your component series, because spool tables, ratings and dimensional drawings differ between series. If you are unsure which series you have, send us the nameplate.
Send us the nameplate. We will identify the valve.
Livingston & Haven has been supplying and repairing industrial hydraulics from Charlotte, North Carolina since 1947. We are an authorized Bosch Rexroth distributor. If you have the code, order it. If you do not, an application engineer will work it out with you.
