Independent third-party repair of servo and proportional valves on Nagata injection molding machines. Yuken proportional valves, Bosch Rexroth 4WRZE / 4WRZ, and legacy Tokimec (JTEKT) hardware rebuilt at the component level on the bench. One-year warranty on parts and workmanship.
Fig. 01 — Bosch Rexroth proportional valve from a Nagata injection molding
Yuken
Proportional valves
Bosch Rexroth
4WRZE / 4WRZ series
4 platforms
Seen at the bench
1 year
Parts & workmanship
Injection MoldingNagataNA / NB SeriesYuken & RexrothYukenBosch RexrothMoogParkerInjection MoldingNagataNA / NB SeriesYuken & RexrothYukenBosch RexrothMoogParker
N100 Where these valves sit
Four Nagata machine contexts
Nagata is a Japanese builder of hydraulic injection molding machines from roughly 50 tons up through 450+ tons. Below are four common contexts where Nagata valves end up at the bench.
N110
NA Series presses
Nagata's core injection molding platform: NA-150, NA-220, NA-350, NA-450. Yuken proportional and Bosch Rexroth valves come off these for rebuild.
N120
NB Series presses
Nagata's mid-range line. The same family of Yuken and Rexroth valves comes through the bench.
N130
50–220 ton legacy units
Smaller Nagata machines running Yuken proportional valves and, on older units, Tokimec (JTEKT) valves that are tough to source new in North America.
N140
350–450+ ton higher-flow machines
Larger Nagata frames. Bosch Rexroth 4WRZE / 4WRZ proportional directional valves and Yuken bodies come through routinely.
Each unit is opened, cleaned, inspected, and rebuilt at the component level. Failed parts come from inventory or off donor units. Bench verification before ship.
N210
Spool & sleeve service
Spool wear, contamination scoring, and lap restoration on Yuken, Rexroth, and Tokimec valve bodies pulled from Nagata presses.
N220
Coil & solenoid rebuild
Burned proportional coils and degraded solenoid windings replaced. Bench testing confirms drive current and dither response.
N230
Seal & o-ring kit
Full seal replacement with modern materials. Hardened or cracked elastomers from years of run time are pulled and renewed.
N240
Pilot stage cleaning
Pilot orifices flushed, jet pipe / nozzle flapper inspected on servo units, and feedback wires checked for wear at the pilot.
N250
Bench testing
Hagenbusch and older-style hydraulic stands. Flow, null, and dynamic response verified against documented procedure before ship.
N260
Hardware repair scope
NC Servo handles the valve hardware. PLC programming, parameter setup, and machine-side controller work stays with the customer or OEM.
Worn spool lands and contaminated orifices on Yuken proportional valve bodies. Bench cleaning, lap restoration, and seal replacement bring the valve back to spec.
Internal leakage
Internal leakage past the spool on aged Yuken and Tokimec bodies after years of cycling.
Spool stiction
Contamination buildup and spool stiction on Bosch Rexroth 4WRZE / 4WRZ proportional valves.
Coil & electrical failure
Proportional coils on Yuken and Tokimec valves degrade from heat cycling, moisture ingress, and voltage spikes. Failed coils drop the valve into a fail-safe position.
N500 Workflow
From part number to ship-back
Same four-step path through the shop whether the unit is a Yuken proportional, a Rexroth 4WRZE, or a legacy Tokimec valve.
N510
Get in touch
Call or email with the part number, machine model (NA-220, NA-350, etc.), and a photo of the nameplate if it helps.
N520
Bench review
Tech opens the unit, inspects pilot, spool, and coil, and runs it on the hydraulic stand to confirm the failure.
N530
Cost & approval
We call back with the cost and a rough turnaround. Nothing is started without your sign-off.
N540
Repair, test, ship
Failed components replaced from inventory or off donors, the valve verified under pressure, and shipped back.
N600 Common questions
Common questions about Nagata valve repair
Application-specific questions. For brand-specific FAQs, see the dedicated brand page in the brand list above.
Do you provide Nagata machine programming or software configuration?
No. We repair hardware components only: servo valves, proportional valves, and servo drives at the component level. We do not provide PLC programming, parameter configuration, software services, or system integration. If parameters are stored in external controllers, the customer or OEM configures them after the hardware repair.
What types of valves come off Nagata injection molding machines?
Most Nagata machines run Yuken proportional valves. Higher-flow configurations bring in Bosch Rexroth 4WRZE or 4WRZ proportional directional valves. Older Nagata machines often have Tokimec (now JTEKT) valves. All of these come off the bench for rebuild.
Can you repair valves from older Nagata machines?
Yes. Legacy Nagata units, including ones with Tokimec (JTEKT) hardware no longer in current production, come through the bench regularly. Component-level rebuild typically brings these valves back to working condition. If a body is past saving we will tell you.
Why are Nagata replacement parts hard to find?
Nagata is a smaller, mid-tier Japanese builder with limited distribution and parts support in North America. OEM components often need to come direct from Japan, which stretches lead time and cost. Rebuilding the existing valve sidesteps that supply path.
Can you repair Bosch Rexroth 4WRZE valves pulled from a Nagata machine?
Yes. The 4WRZE and 4WRZ proportional directional valves come through the bench routinely. The repair runs the same whether the valve came off a Nagata press or any other builder.
What is the warranty?
One year on parts and workmanship for repairs and rebuilt units. Standard exclusions apply for contamination, improper installation, and out-of-spec operation. Flushing and filtering the hydraulic system before reinstalling a repaired valve is recommended.
N700 More from NC Servo
Related repair coverage
Other molding-machine builder pages, the broader category hubs, and the brand pages most relevant to Nagata.
Give us a call or send a part number with the machine model and a quick description of what the valve is doing. We'll check inventory, suggest a rebuilt match if we have one, and walk through repair options if we don't.
