Altech Corp.: 85-A STH5 Hinge-Type Terminal Blocks Resist Vibrations and Provide Fast, Safe Access

August 17, 2026
In power distribution, heavy-duty machinery and transportation applications, vibrations can weaken a terminal block’s clamping power and loosen wire connections. The resulting power and signal failures can lead to unwanted system downtime, fire and shock risks, or other safety issues. Fortunately, one type of terminal block design makes secure connections possible while also providing easy access for installation and maintenance.
Hinge-type terminal blocks, such as the 85-A STH5 from Altech Corp., ensure secure connections and allow technicians to easily open the circuit quickly and safely. Here are the design elements that make these benefits possible:
- Hinged carrier with bolt feed through terminals. The captive nut is housed inside a plastic enclosure with a hinge for easy access. The ring lugs are bolted to the terminal block’s flat current bar, providing a high clamping force that ensures a secure, vibration-resistant connection. With the STH5, technicians only need a standard flathead screwdriver to tighten the connection and keep it in place.
- Reliable ring lugs. Not only do standard fork-type bolted rings stay put during vibrations, they cannot accidentally fall out of the hinged housing. Terminals that use fork-type rings also have a large contact area that keeps resistance low while minimizing heat.
- Safe and fast wiring. The touch-proof terminals include a flip-to-open plastic hinged cover that makes installation, inspection and maintenance fast and easy. When flipped open, the IP20 hinge shrouds the conductive parts for safety.
Altech’s STH5 85-A hinge-type terminal block comes with all of these design elements, accepts 22-4 AWG wires and has a 600-V rating. It also offers the following features:
- Support for two-lug connectivity.
- Polyamide 66 insulation.
- Optional DIN rail, end plate and marking tags.
Thanks to the STH5’s exceptional vibration resistance, this terminal block is well-suited for transportation and semiconductor equipment as well as many other heavy-duty applications.






