SV Technocrats India's lug keys (also known as saddle keys) are a type of key used to transmit torque between a shaft and a hub without machining a keyway into the shaft. Instead, they sit on top of the shaft and are typically held in place by friction or mechanical means.

🔧 Lug Key (Saddle Key) – Overview

• Function: Transmits torque between the shaft and hub without cutting a keyway into the shaft.

• Use Case: Typically used in light-duty applications or temporary assemblies.

• Installation: Fits into a keyway cut only in the hub. The bottom of the key rests on the shaft's surface.

🔩 Types of Lug Keys (Saddle Keys)

1. Flat Saddle Key:

o Flat bottom; rests flat on the cylindrical shaft surface.

o Relies mainly on friction between the shaft and key for torque transmission.

o Less secure than sunk keys.

2. Hollow Saddle Key:

o Curved bottom to match the shaft’s surface.

o Provides a better fit and increased contact area compared to flat saddle keys.

o Still not as strong as a key with a full keyway.

⚙️ Applications

• Used where:

o The shaft cannot be weakened by machining a keyway.

o The connection is temporary or adjustable.

o The torque requirements are relatively low.

• Common in pulleys, light-duty couplings, or tool fixtures.

✅ Advantages

• No machining of the shaft required.

• Easy to assemble/disassemble.

• Preserves shaft strength.

❌ Disadvantages

• Low torque capacity.

• Can slip under load (especially flat types).

• Not suitable for heavy-duty applications.

SV Technocrats India is leading supplier of machine keys in Pune.