Ex-stock Mumbai · Pan-India Delivery
Industrial Fasteners — Manufacturer & Supplier in Mumbai
Lock nuts (KM/HM series), parallel machine keys, wood rough keys and cotter pins (split pins) stocked ex-Mumbai. DIN 981, DIN 6885, DIN 94, IS 549 & 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
DIN 94 / ISO 1234 • IS 549 • 1/16″ – 1/2″ dia
Cotter Pin (Split Pin)
Ex-stock Mumbai · Special sizes: 5–7 days
Cotter pins (also called split pins or castle pins) are double-stranded wire fasteners made by folding semi-circular wire in half. Inserted through a hole in a bolt, clevis pin, or shaft, the two legs are spread apart to lock the assembly — preventing nuts, clevis pins, and shafts from backing out under vibration or load. Stocked in Mild Steel (MS) and Stainless Steel (SS 304/316) to suit both general engineering and corrosion-resistant applications.
| Standards | DIN 94, ISO 1234, IS 549, BS 1574 |
|---|---|
| Diameter Range | 1/16″ – 1/2″ (approx. 1.6mm – 13mm) |
| Length Range | 1/2″ – 6″ |
| Material | Mild Steel (MS), Stainless Steel SS 304 / SS 316 |
| Finish | Self colour (MS), Bright (SS) |
| Pricing | Per 100 pieces |
Common Applications
- Castle & Slotted Nut Locking
- Clevis & Yoke Pin Retention
- Agricultural Equipment
- Automotive Brake & Steering Linkages
- Material Handling & Rigging
- General Engineering Assemblies
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.
What is a cotter pin / split pin used for?
A cotter pin (also called a split pin or cotter key) is a metal fastener made from a semi-circular wire bent double. It is passed through a drilled hole in a bolt, shaft, or clevis pin, and the two legs are spread apart to lock the assembly. Common uses include securing castle nuts on axles and wheel hubs, preventing clevis pins from walking out in linkages, and safety-locking bolts in agricultural machinery, construction equipment, and marine hardware.
What sizes of cotter pins do you stock?
We stock MS cotter pins from 1/16″ to 1/2″ diameter and 1/2″ to 6″ length per DIN 94 / ISO 1234 / IS 549. SS 304 and SS 316 grades are available on request. Contact us with your diameter, length, and quantity for pricing and lead time.
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