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What is a spanner wrench?
A spanner wrench, also known as an adjustable wrench, is a hand tool used to turn nuts and bolts. It consists of a movable jaw adjustable by a worm gear, allowing it to be used with different sizes of fasteners. The jaws have flat, smooth surfaces designed to engage with the flat sides of a fastener’s head. Applying force to the handle pivots the movable jaw towards the stationary jaw, tightening the jaws’ grip on the fastener. This allows the fastener to be turned by rotating the wrench’s handle.
Advantages of Using a Spanner Wrench
Versatility
The key advantage of a spanner wrench is its versatility. By adjusting the movable jaw, a single spanner can be used with a wide range of bolt and nut sizes, typically from 1/4″ to 1″. This eliminates the need to have multiple fixed sized wrenches to fit every fastener on a project. One adjustable wrench replaces an entire set of fixed wrenches.
Accessibility
The adjustable range of a spanner wrench allows it to fit fasteners in tight spaces that a fixed wrench may not. Being able to insert the jaws into a confined space and then expand them to grip the fastener head makes the spanner ideal for hard to reach nuts and bolts. This versatility also aids in disassembling machinery or vehicles where removing the surrounding components to access fasteners with other wrenches is not feasible.
Portability
Carrying a full set of fixed wrenches requires a large tool box with multiple drawers or trays to organize the various sizes. An adjustable wrench provides equivalent functionality in a single tool that requires minimal storage space. This portability makes it ideal for field work or mobile tool kits where minimizing the number of tools is essential.
Applied Force
The long handles of most spanner wrenches allow increased torque to be applied compared to small fixed wrenches. The adjustable jaws maintain a tight grip on the fastener without slipping under high force. This makes spanners well suited for tasks requiring high torque such as loosening rusted nuts or bolts.
Types of Spanner Wrenches
Standard Adjustable Wrench
The most common type of adjustable wrench has a straight handle with parallel flat jaws. Jaw width capacity generally ranges from 1-3 inches depending on handle length. The worm gear adjuster is located behind the movable jaw. Standard adjustable wrenches are versatile general purpose tools suitable for most common fastening and disassembly tasks.
Angle Head Adjustable Wrench
These feature a head with the jaw at an angle to the handle, typically around 15-45 degrees. The offset head allows the wrench to fit into narrow spaces and provides greater access to confined fasteners. The angled jaws also provide increased grip and turning force. Angle head adjustable wrenches are designed for tightening or loosening fasteners in narrow spaces.
Pliers Style Adjustable Wrench
Instead of a flat solid handle, these wrenches have plier style handles with handles that pivot. While gripping and turning force is reduced compared to fixed handle models, the pivoting handles allow greater access to fasteners in extremely tight areas. Useful in very confined spaces where standard adjustable wrenches won’t fit.
Vise Grip Style Adjustable Wrench
These adjustable wrenches have a double pivot handle connected to a short metal frame with threaded jaws. They function similar to locking pliers, with the pivoting, scissor-like handles providing a strong grip on the workpiece. Useful for clamping and turning smooth fasteners in confined areas.
Pipe Wrench Style Adjustable Wrench
Designed specifically for gripping pipes and round workpieces, these have a heavy duty frame and thick, serrated jaws that provide an extremely strong grip. The knurled adjustment knob allows quick adjustments. Pipe wrench style adjustable wrenches are ideal for heavy turning applications.
How to Use a Spanner Wrench
1. Select the Proper Size
Determine the size of the nut or bolt head the wrench will be used on. Adjust the jaws of the wrench to open slightly larger than this dimension. Proper jaw width will allow maximum grip on the sides of the fastener.
2. Insert Jaws onto Fastener
Fit the jaws of the wrench over and around the top sides of the nut or bolt head. Center the jaws on the fastener to distribute gripping force evenly.
3. Tighten Jaws
Turn the worm gear or knob on the wrench to tighten the jaws until they secure tightly on the fastener. Pressure should be firm but not excessive. Proper tightness will allow adequate force to be applied through the handle.
4. Position Yourself for Leverage
With larger wrenches, brace yourself and take a stance so you can use your body weight to fully lever the wrench handle. Grip the tool near the head for optimal leverage.
5. Turn Wrench and Fastener
Pull or push the wrench handle to turn the fastener. Keep the tool’s head as close to the nut or bolt as possible so force is transmitted directly into the axis of the fastener. Using smooth full strokes allows you to fully utilize the wrench’s length.
6. Loosen Jaws and Remove
Once the fastener is tightened or loosened sufficiently, turn the adjustment knob to loosen the jaws until they can be removed from the fastener.
Common Uses
Auto Repair and Maintenance
Adjustable wrenches are standard equipment for any auto mechanic. Their versatility to tackle the range of fastener sizes found on vehicles makes them essential repair tools. Typical uses include:
- Removing or tightening lug nuts when changing a tire
- Loosening or tightening bolts to remove engine components
- Adjusting fittings, clamps, and belts
- Assembling or disassembling suspension components
Mechanics keep a standard adjustable wrench at hand for quick adjustments or fast jobs where retrieving a socket set is not practical. The ability to fit in tight spaces makes them ideal for engine compartment work.
Bicycle Repair and Maintenance
Bicycles have many nuts and bolts that must be loosened for repairs and maintenance. The versatility and compact size of adjustable wrenches allows them to tackle the variety of fastener sizes. Typical uses include:
- Removing or installing wheel axle nuts
- Adjusting fittings on brake and derailleur cables
- Loosening or tightening bolts on frames and components
- Assembling or disassembling gearing and chains
For bike repairs on the go, a standard adjustable wrench easily fits in a toolkit to provide an all purpose tightening and loosening tool. They eliminate having to carry multiple fixed size wrenches.
Plumbing Tasks
Plumbers rely heavily on adjustable wrenches for the convenience of adjusting to any pipe fitting size on the job. Typical plumbing uses include:
- Assembling or disassembling pipe joints and fittings
- Tightening and loosening pipe clamps and straps
- Removing or replacing valves, traps, and couplings
- Securing fittings and pipes during installation or repairs
The ability to firmly grip round components like pipes makes adjustable wrenches well suited for plumbing applications. Models with pipe wrench style jaws excel at providing high grip strength.
Electrical Maintenance
Electricians use adjustable wrenches for a wide variety of electrical hardware:
- Tightening or removing conduit fasteners
- Securing wire terminals and bus bars
- Assembling cable trays, raceways, and channel struts
- Adjusting electrical box and enclosure hardware
Their versatility and compact size makes adjustable wrenches a convenient tool for electricians for basic assembly and adjustments.
Machinery Maintenance
The prevalence of nuts, bolts, and fittings on industrial machinery makes adjustable wrenches invaluable maintenance tools. Typical applications include:
- Removing housing and cover panels using fastener hardware
- Tightening fittings and connections on fluid power lines
- Securing guards and shields prior to operation
- Assembling and adjusting machine components and frameworks
Machinery maintenance and repairs often require access to confined spaces which adjustable wrenches are ideally suited for. Their wide gripping range allows tackling machinery fasteners of all sizes.
Conclusion
Adjustable spanner wrenches are versatile, durable hand tools that utilize a movable jaw and worm gear mechanism to tighten around objects of various sizes. This adaptability allows a single wrench to be used for multiple nuts, bolts, pipes, fittings, and other fixtures, eliminating the need for sets of fixed size wrenches. The compact size provides access to fasteners in tight spaces. Models designed specifically for maximum grip strength on pipes or other rounded objects are available. Standard adjustable wrenches are essential for auto repair, plumbing, machinery maintenance, bicycle repair, and other applications involving various fastener sizes. They represent an efficient combination of functionality, portability, and convenience in a single tool.