Answers, before you commit to a part

A shaft coupling connects a driving and a driven shaft to transmit torque and rotation while accommodating small misalignment and vibration. The quality of the design, tolerances and materials determines its reliability and service life.

• Basics

A rigid coupling needs exactly aligned shafts and offers maximum torsional stiffness at low cost. A flexible coupling accommodates angular, parallel and axial misalignment and absorbs vibration and shock, protecting bearings and seals. That makes it the right choice for servo and stepper positioning.

• Basics
• Selection

Clean the components, align the shafts (dial indicators help), then fasten with set screws, clamping bolts or keys and tighten uniformly with a torque wrench to the specified torque. Keep the specified gap to avoid metal-to-metal contact.

• Installation

Servo couplings are chosen for high-speed, high-dynamic motion with zero-backlash accuracy. Stepper couplings run at lower speed with high torque and good load holding, and are cost-efficient. Both need low inertia and high torsional rigidity for precise positioning.

• Selection

A flexible coupling accommodates misalignment, absorbs vibration and shock, and protects bearings and seals from load, which extends the life of the whole drive train.

• Basics

NBK supplies disc, Oldham, cross-joint, high-gain rubber, slit (beam) and jaw type flexible couplings, each suited to different combinations of torque, rigidity, misalignment and environment.

• Basics
• Selection

Work in four steps: choose the type (motion control vs power transmission), then the material for the environment, then the size for torque, space and bore, and finally the fastening method (set screw, clamping or keyway). Our engineers help you match all four.

• Selection

It joins two rotating shafts end-to-end to transmit torque while allowing minor misalignment, absorbing shock and reducing vibration, which protects bearings and seals in the drive train.

• Basics

Clean the shaft ends, align them, mount the hubs (or the Oldham/jaw insert), keep the specified gap to avoid metal-to-metal contact and tighten to the specified torque with a torque wrench. Download the installation manual for step-by-step guidance.

• Installation

NBK offers miniature couplings down to about 6 mm outer diameter for 1 mm shafts, such as the Oldham MOR 6 and beam coupling MSH 8, used in compact precision instruments.

• Selection

Yes. Stainless steel slit couplings (XSTS, XWSS, MSTS) and cleanroom/vacuum Oldham couplings (MOP, MOHS) are vacuum compatible, made from low-outgassing, corrosion-resistant materials and available clean-washed and clean-packed.

• Vacuum
• Cleanroom

Yes. The XSTS, MOP and MOHS couplings are made from low-particle materials and can be ultrasonically or IPA cleaned and cleanroom-packaged for semiconductor, medical and food applications.

• Cleanroom

Yes. From vacuum-compatible to cleanroom-grade screws, many products are available from inventory and can be ordered from a single piece, which is ideal for prototyping and low-volume builds.

• Selection

A vented screw has a through-bore that lets trapped air escape from blind or tapped holes, preventing the virtual leaks that slow pump-down and contaminate a vacuum chamber. NBK offers them in stainless steel, titanium and low-outgassing materials.

• Vacuum

Titanium, phosphor bronze, ceramic and specific austenitic stainless grades offer low magnetic permeability, suited to MRI, semiconductor and precision-measurement systems. For critical uses, specify a maximum permeability (µr value).

• Non-magnetic
• Selection

A captive screw stays permanently attached to the component so it cannot be lost during operation or maintenance. This is ideal for frequently opened covers, panels and access points, and it prevents parts falling into machinery.

• Basics