EKB Brand KM8 Lock Nut | M40×1.5 | Bearing Shaft Lock Nut

EKB Brand KM8 is a shaft lock nut with M40×1.5 metric thread, designed for locking bearing inner rings on shafts. It is used together with MB8 lock washer and matching adapter sleeve or withdrawal sleeve for tapered-bore bearing mounting.

Basic dimensions: thread diameter 40 mm, outside diameter 58 mm, width 9 mm. Material: 20# steel. Weight approx. 0.078 kg per piece.

Confirm the complete component combination (lock nut + washer + sleeve) with your bearing model and shaft diameter before ordering.

Product Specifications

Note: Confirm thread size, outside diameter and width against your drawing before ordering.

Matching Components

KM8 lock nut is normally used together with the following components:

• Lock washer: MB8 — bent into the KM8 slots after tightening to prevent loosening.

• Adapter sleeve: H308 / H2308 — for mounting 40 mm bore tapered-bore bearings onto a 35 mm cylindrical shaft. Confirm sleeve compatibility with the specific bearing model before ordering.

• Hook spanner: HN8 / HN8-9, depending on the tool specification.

If you are replacing an existing lock nut, send us the original part number, thread size or a photo, and we will help confirm the matching washer and sleeve combination.

Key Features

• M40×1.5 Metric Fine Thread — Provides precise axial adjustment when locking bearing inner rings.

• 4 Slots Around Circumference — For hook spanner tightening, with slot width 6 mm and depth 2.5 mm.

• 20# Steel Construction — Suitable for general bearing mounting and shaft locking applications.

• Used with MB8 Lock Washer — Washer tabs are bent into the nut slots to prevent rotation after tightening.

• Standard Dimensions — Manufactured to DIN 981 / ISO 2982-2 reference dimensions.

Measured Dimensions & Quality Verification

Each KM8 lock nut supplied by EKB is dimensionally checked before shipment, with thread, outside diameter and width verified to the drawing tolerance.

Documents Available:

• Dimensional drawing (technical sketch)

• Dimensional inspection report / measured data sheet

• Material certificate (on request)

• Packing list per order

Packaging, Trading Terms & Lead Time

Packaging — Anti-rust wrapped, individually bagged, then carton as required. Neutral or custom-brand packaging available on request.

Trading Terms — EXW / FOB / CIF available; payment by T/T (30% deposit + balance before shipment, or as agreed).

Lead Time — Stock items ship promptly; production orders depend on quantity — please confirm with our sales team.

Typical Applications

• Locking bearing inner rings on tapered shafts

• Adapter sleeve and withdrawal sleeve mounting

• Gearboxes, motors, pulleys and shaft assemblies

• General industrial machinery requiring axial bearing location

Dimensions and Replacement Compatibility

The basic dimensions of KM8 are:

• Thread: M40×1.5 (thread diameter 40 mm / 1.575")

• Outside diameter: 58 mm (2.283")

• Width: 9 mm (0.354")

A lock nut with the same M40×1.5 thread is not necessarily an interchangeable replacement — outside diameter, width and slot configuration should also match. Confirm the complete dimensions against your original nut before ordering.

Not sure which lock nut size you need? See our Bearing Identification Service — send us a photo or your shaft size, and we will recommend the matching lock nut, washer and sleeve.

Other KM Series Lock Nuts

Looking for a different shaft size? We also supply:

• KM2 (M15×1)

• KM9 (M45×1.5)

• KM16 (M80×2)

Contact us with your thread size for the full KM, KMK and KMT series list.

Need a KM8 Lock Nut?

EKB supplies lock nuts, lock washers and adapter sleeves for industrial bearing mounting. When contacting us, please include:

• Required lock nut model and quantity

• Whether you need matching MB8 washers or adapter sleeves

• Bearing model or shaft diameter, if known

• Required delivery date

We will confirm stock, lead time and the correct component combination for your application.

Browse This Category

See our full range of Lock Nuts & Bearing Accessories.

About EKB

EKB Bearing is an integrated manufacturer and exporter of bearings and bearing accessories. We combine our own 18,000 sqm production facility — equipped with 13 automated production lines and 42 high-precision testing units — with our international sales team, and our products are exported to 66 countries. Our manufacturing facility operates under a formal ISO 9001:2015 quality management system (GB/T 19001-2016).

We support customers with difficult-to-source bearing and accessory requirements, including special-dimension, inch-size and replacement parts.

Frequently Asked Questions

What is KM8 used for?
KM8 is a shaft lock nut used to lock bearings with tapered bore onto adapter sleeves or directly onto tapered shafts. It is paired with MB8 lock washer.

What thread is KM8?
M40×1.5 metric fine thread, fitting a 40 mm shaft.

What washer goes with KM8?
MB8 lock washer. The washer tabs are bent into the slots of KM8 after tightening.

What adapter sleeve goes with KM8?
H308 or H2308 adapter sleeves, used for mounting 40 mm bore tapered-bore bearings onto a 35 mm cylindrical shaft. Confirm with the specific bearing model.

How many slots does KM8 have?
4 slots around the circumference, for hook spanner (HN8 / HN8-9) tightening.

What is the weight of KM8?
Approx. 0.078 kg (0.172 lb) per piece.

Can you provide inspection records?
Yes. Each lock nut is dimensionally checked before dispatch and measurement data can be supplied with the order.

Request a Quote

Looking for KM8 or a different size lock nut? Send us your thread size, quantity, or the bearing model you are mounting. EKB will help confirm the correct nut, washer and sleeve combination before you order.

Contact EKB