Wrenches, Spanners, and Sockets
Wrenches and sockets are among the most frequently used hand tools offshore. Incorrect use can result in pinched fingers, rounded fasteners, tool slippage, and serious line-of-fire injuries.
1. Choosing the Correct Size
Using the wrong-size tool leads to:
- Slippage
- Rounded bolt heads
- Sudden loss of grip
- Increased force required
Golden Rule:
A wrench or socket should fit snugly with no play.
2. Types of Wrenches and Their Uses
• Open-End Spanner
- Fast access in tight areas
- Not ideal for high torque
- More risk of slippage
• Combination Wrench (Spanner)
- Closed end reduces slippage
- Ideal for loosening tight bolts
• Adjustable Wrench
- Only for temporary use
- Increased risk of rounding
- Never use on high-torque tasks
Adjustable wrenches should NOT replace the correct spanner size.
3. Socket Types and Safe Operation
• Standard Sockets
Used for general maintenance tasks.
• Impact Sockets
Thicker walls designed for impact tools.
• Deep Sockets
For long studs and recessed bolts.
Safety Tips:
- Ensure fully seated before applying force
- Use extensions only when required
- Never use “cheater bars” unless approved
4. Applying Torque Safely
Incorrect torque causes:
- Bolt stretching
- Equipment leaks
- Structural failures
Safe torque practices:
- Pull, don’t push
- Keep wrist aligned
- Keep body balanced
- Use torque wrenches when required
5. Line-of-Fire Awareness with Wrenches
Always ask:
- “Where will my hand go if this slips?”
- “Am I directly behind the force?”
- “Is my body stable if sudden movement happens?”
Key Takeaways
- Correct tool size = safety + efficiency
- Closed-end tools reduce slippage
- Adjustable wrenches are last resort tools
- Proper torque prevents rework and equipment damage