Ex-stock Mumbai · Pan-India Delivery
Industrial Fasteners — Manufacturer & Supplier in Mumbai
Lock nuts (KM/HM series), parallel machine keys, and wood rough keys stocked ex-Mumbai. DIN 981, DIN 6885 & IS 2048 grades. Custom sizes available. Pan-India delivery since 1971.
DIN 981 • KM0 – HM76 • M10 – M460
Lock Nut (KM / HM Series)
Ex-stock Mumbai · Custom sizes: 5–7 days
KM locknuts and HM lockwashers form a two-component bearing locking system. The KM nut is a precision-threaded slotted round nut that tightens against the inner ring of a rolling element bearing. The MB lockwasher's inner tab locates in the shaft keyway, and once the nut is tightened, an outer tab is bent into one of the nut slots — mechanically locking the nut against rotation and maintaining bearing preload indefinitely. Available in hardened and ground versions for precision spindle applications.
| Standards | DIN 981 (KM/HM series) |
|---|---|
| Size Range | KM0 (M10×0.75) – HM76 (M380×4) |
| Material | Carbon Steel (hardened), Alloy Steel |
| Thread | Fine metric thread per DIN 981 |
| Lockwasher | MB series (sold separately or as set) |
| Finish | Phosphated, Zinc plated |
Common Applications
- Rolling Bearing Locking
- Spindles & Mandrels
- Machine Tool Axes
- Gearboxes
- Pump & Motor Shafts
DIN 6885 • IS 2048 • 2×2 – 100×50
Machine Key (Parallel Key)
Ex-stock Mumbai · Custom sizes: 5–7 days
Parallel keys (machine keys) are rectangular precision-machined keys that fit simultaneously into keyways on a shaft and a hub, transmitting torque between the two components. They allow axial sliding of the hub relative to the shaft (sliding key) or are fixed in position (sunk key). Available as Form A (rounded both ends), Form B (square both ends), and Form C (one round, one square end) to suit different keyway configurations.
| Standards | DIN 6885, DIN 6886, IS 2048 |
|---|---|
| Material | Carbon Steel (C45), Alloy Steel, SS 304 |
| Size Range | 2×2 mm – 100×50 mm (W×H) |
| Forms | A (round ends), B (square ends), C (mixed) |
| Tolerance | h9 (key width) |
| Finish | Bright machined |
Common Applications
- Gear-to-Shaft Connections
- Pulley & Sprocket Drives
- Coupling Assemblies
- Motor Output Shafts
- Machine Tool Drives
IS 2048 • 2×2 – 50×30
Wood Rough Key
Ex-stock Mumbai · Custom sizes: 5–7 days
Wood rough keys (also known as saddle keys or flat keys in some applications) are supplied as raw bar stock in standard key cross-sections, intended to be cut to length and fitted on-site. They are the economical choice when a standard finished key length is not available, or when the application requires site fitting. The raw bar is machined to the exact width and height tolerance and can be cut by the user to any required length.
| Standards | IS 2048 |
|---|---|
| Material | Carbon Steel (C45), Mild Steel |
| Size Range | 2×2 mm – 50×30 mm (W×H) |
| Supply Form | 300 mm bar / custom length |
| Tolerance | h9 (width) |
| Finish | Bright drawn / Ground |
Common Applications
- General Shaft-Hub Connections
- Site-fitted Key Applications
- Repair & Maintenance
- Custom-length Requirements
- Agricultural Equipment
Common Questions
Fastener FAQ
What is a KM locknut used for?
KM locknuts (DIN 981) lock the axial position of rolling element bearings on a shaft. Used with MB lockwashers, the nut is tightened against the bearing inner ring and a lockwasher tab is bent into a nut slot to prevent rotation — maintaining bearing preload under all operating conditions.
What is the difference between a parallel key and a woodruff key?
A parallel key (machine key) is rectangular and fits keyways on both shaft and hub, transmitting torque and optionally allowing axial sliding. A woodruff key is semi-circular and self-aligning in its shaft keyway — easier to fit but with lower torque capacity. Impex stocks both parallel keys (DIN 6885) and supplies woodruff keys on request.
What sizes of KM locknuts do you stock?
We stock KM0 through HM76 (M10×0.75 to M380×4 thread) per DIN 981. For sizes beyond HM76 please contact us to confirm availability and lead time.
Do you supply machine keys in stainless steel?
Yes. Machine keys (parallel keys) are available in SS 304 on request. These are commonly used in food processing machinery and chemical plant where standard carbon steel would corrode. Contact us with your size requirements for pricing and availability.
Can you supply MB lockwashers with KM locknuts?
Yes. MB lockwashers are stocked alongside KM/HM locknuts and can be supplied individually or as matched pairs. Both are available from MB0 to MB72 sizes.
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