What Is a Single Open-End Spanner?
A single open-end spanner is a tool used primarily for tightening and loosening hexagonal bolts and nuts.
The part that grips the bolt or nut is called the “bore,” and the width of the U-shaped opening is called the “two-sided width.” A double-end spanner has a bore on both ends, whereas a single open-end spanner has a bore on only one end.
Spanner and wrench have the same original meaning in British and American English, respectively.
Uses of Single Open-End Spanners
Single open-end spanners are used in various applications, from general DIY to professional workplaces. Single open-end spanners are mainly useful for tightening and loosening hex bolts and nuts. They are indispensable tools in all situations, including machinery and equipment, precision instruments, vehicles, engines, construction, furniture, and DIY.
The single open-end spanners have an open U-shaped tip, which allows it to be inserted from the side and is used for working on bolts and nuts in tight spaces. Since the single open-end spanners support and tighten at two points, it is not a tool suitable for applying large forces. Therefore, it is generally used as a temporary stop.
Most single open-end spanners have holes in the handle, through which a cord can be threaded to prevent it from falling when working in high places. Another advantage over double-ended wrenches is that they are easier to hold since they have a bore on only one side.
Principle of Single Open-End Spanners
The single open-end spanners use the “leverage principle” to tighten or loosen a bolt or nut by generating a large force with a small force. The fulcrum is the center of the bolt or nut, the force point is the part of the hand holding the single open-end spanners, and the action point is the angle between the bolt or nut and the two points where the spanner meets.
By holding and turning the end of the single open-end spanners, the bolt or nut can be easily tightened or loosened. The single open-end spanners have two points of contact with the bolt and nut, while the wrench has six points of contact. Therefore, the wrench can apply more force to tighten the bolt or nut more firmly.
Types of Single Open-End Spanners
1. Single Open-End Spanners
One side of the handle has a bore section that grips the bolt or nut. The two side widths are fixed. Convenient when the size of the bolt or nut to be used is the same.
2. Thin Spanner
This is a thinner-than-usual wrench. Used when working in tight spaces or when the bolt or nut is thin. Thin spanners are not suitable for large bolts and nuts, but useful for small bolts and nuts.
3. Percussion Spanner
Normal single open-end spanners are not strong enough to be struck with a hammer or the like. Applying a force stronger than necessary may damage the bolt or nut or deform the wrench itself.
This striking wrench is strong enough to endure striking the handle with a hammer. It is used when removing or retightening rusted nuts and bolts is necessary.
How to Select Single Open-End Spanners
The use of single open-end spanners suited to the purpose of work will affect work efficiency, safety, and accuracy of the finished product.
1. Size
The part that clamps the bolt or nut is fixed, so select a wrench that matches the size of the bolt or nut. The size is not the diameter or radius. However, the distance between the “width of two sides” where the single open-end spanners fit the bolt or nut.
The size is marked in numbers on the handle. Basically, the size is marked in meters, but in rare cases, some sizes are in inches, so you need to check.
2. Similar Products
Some wrenches have a circular bore. Since the bore hits the entire circumference of the bolt or nut, it is difficult to dislodge or tamper with.
There are also single open-end spanners, double open-end spanners with bores on both ends and combination wrenches consisting of both a wrench and a spanner.
Other Information on Single Open-End Spanners
How to Use Single Open-End Spanners
- First, turn and tighten the bolt or nut by hand.
- Place the bolt or nut so that it is firmly seated in the innermost part of the bore. The bore should be parallel to the bolt and nut.
- Start by turning the single open-end spanner and tighten the bolt or nut. It is more efficient to hold the end of the handle and turn it to transmit power more efficiently.
- If you want to loosen a bolt or nut that is stuck and hard, apply oil and leave it for a while before turning.