Spring or screw terminals - which should you choose?
Spring-clamp and classic screw terminals both connect conductors reliably, yet they differ sharply on vibration, speed and maintenance. This guide compares both technologies against concrete criteria and shows when each terminal is the right choice.
View terminal blocksHow do the two clamping principles differ?
The screw terminal presses the conductor against a busbar through a thread - the installer sets the force via the tightening torque. The spring-clamp terminal instead generates contact force through a pre-loaded stainless-steel spring that pushes permanently and independently of the operator.
With the screw joint, quality depends on correct torque: too little raises contact resistance, too much damages fine-stranded conductors. The spring-clamp terminal always applies the same defined force and even compensates for the settling and creep of the copper over time on its own.
Which terminal withstands vibration better?
Vibration is the main reason spring technology has prevailed in rail, automotive and machine building. A screw can loosen under continuous shock, so the contact pressure drops, contact resistance rises and the clamping point heats up.
The spring follows every mechanical movement of the conductor and keeps the contact pressure constant. That is why spring-clamp terminals are permanently vibration-proof per IEC 60947‑7‑1 and are preferred in applications with high shock and vibration loads.
How much time does the spring terminal save?
Every second counts when wiring. Push-in spring terminals accept a solid conductor or ferrule with a simple push - no tool, no torque, no check. That shortens the wiring time per connection versus the screw terminal by up to 50 percent.
- No re-torque: the spring holds the pressure with no maintenance interval.
- Reproducible: the same contact force at every point, regardless of the installer.
- Tool-light: push-in often needs no tool at all, actuation only uses a screwdriver as a lever.
- Screw terminals stay strong at very large cross-sections and high currents.
- Always fit a ferrule on fine-stranded conductors for push-in.
Matching terminals, jumpers and end stops for the DIN rail.
Read the guideFrequently asked questions
Are spring-clamp terminals really maintenance-free?
In normal operation, yes. The pre-loaded spring keeps the contact force constant over time, so no re-torque is needed as with a screw. A periodic visual check is enough.
Do screw terminals handle higher currents?
At very large cross-sections and high currents, screw and bolt terminals offer more achievable contact force. For typical control wiring up to 16 mm² spring-clamp is equivalent and faster.
Do I need ferrules for spring-clamp terminals?
For fine-stranded conductors, yes, so the strands do not splay and the push-in contact grips cleanly. Solid conductors can be inserted directly.
Why do screw terminals loosen under vibration?
Continuous shock can loosen the thread on its own, lowering the contact pressure and heating the clamping point. The spring follows the movement and keeps the pressure.
Looking for terminal blocks for your application?
We supply spring-clamp and screw terminals to IEC 60947-7-1 including jumpers, end stops and marking - matched to any DIN rail.
Standard-tested
Terminals meet IEC 60947-7-1.
Vibration-proof
Spring force resists vibration for good.
Fast to fit
Push-in saves up to 50 percent of time.
Expert advice
Specialists help you choose.