Product type

JFK locknuts

Axial securing on threaded shafts, from standard to high-precision applications

Not sure which type is the right choice for you? The "Selection guide" section at the bottom of this page will help you identify the best solution for your application. Alternatively, contact us directly for technical assistance.

Standard, precision, and self-locking locknuts: the complete range for every operating condition.

JFK locknuts are threaded devices designed for the axial securing of bearings and mechanical components on threaded shafts. The range is divided into three main families: KM locknuts with metric threads and locking washers, KMT and KMTA precision locknuts with three brass locking set screws, and GUK and GUP self-locking locknuts with an integrated self-locking system. Each family offers specific characteristics in terms of precision, ease of installation, and locking capability.

Find the product

Three types for every shaft securing requirement

KM locknuts for standard applications; KMT and KMTA precision locknuts for high-precision applications; GUK and GUP self-locking locknuts for environments with vibration and dynamic loads.

KM Locknuts

Metric thread · Four external grooves · With locking washers

KM locknuts feature a metric thread and four external grooves for use with a hook spanner. Combined with locking washers to prevent loosening, they provide a standard solution for industrial drive and transmission systems.

KMT and KMTA Precision Locknuts

Three brass locking set screws · High precision · No locking washer required

Three brass locking set screws. High positioning accuracy and adjustability, with no locking washer required. KMT features slots, while KMTA has a smooth outer surface for applications with limited space.

GUK and GUP self-locking locknuts

Integrated self-locking system · Standard and heavy-duty series

Integrated self-locking system. High stability under vibration and dynamic loads. GUK standard series, GUP heavy-duty series for more demanding applications.

TECHNICAL COMPARISON

Which locknut for which application

Concise comparison of the main parameters: locking system, precision, and whether a locking washer is required. For specific sizing requirements, the JFK technical team is available to provide direct support.

Type	Locking	Locking washers	Features and use
KM	With locking washers	Required	Standard solution for transmissions and industrial systems.
KMT / KMTA	Three brass set screws	Not required	High positioning precision; reduced axial space with KMTA.
GUK / GUP	Integrated self-locking mechanism	Not required	Stability under vibration and dynamic loads.

SELECTION GUIDE

Start by identifying the operating conditions

The choice depends on the required level of precision, the available axial space, and the presence of vibration or dynamic loads. Start with the operating condition that best describes your application.

Standard bearing securing on shafts

KM locknuts for most standard industrial applications, used in combination with locking washers.

High positioning accuracy required

KMT locknuts for high-precision positioning without locking washers, thanks to the three brass locking set screws.

Limited axial space

KMTA locknuts feature a smooth outer surface for applications with limited axial space and can also be used as components in non-contact protective guards.

Vibrations and dynamic loads

GUK and GUP self-locking locknuts for operating conditions involving significant vibration or dynamic loads that could loosen conventional solutions.

Have a specific requirement?

Haven’t found the right operating condition?

JFK’s technical team analyses loads, speeds and operating conditions to identify the right solution.

Specific technical requirement Technical support in selecting the right component for your application. Custom-designed product We develop customized solutions tailored to your technical specifications.