What Is an Adjustable Wrench? Sizes and Selection Criteria
An adjustable wrench is a hand wrench whose movable jaw is set by a worm screw to fit hex nuts and bolt heads of different sizes.
An adjustable wrench is a hand wrench whose movable jaw opens and closes on a worm screw so that it fits hex nuts and bolt heads of different sizes; it is also called an adjustable spanner. It is used in maintenance, installation and assembly work, where a fixed wrench of the exact size is not at hand, to turn metric and inch fasteners with one tool.
Sizes
The inch value of an adjustable wrench gives the overall length of the wrench, not the jaw opening. As the length grows, the maximum jaw opening and the torque from the handle increase; a small size is handy in tight spots and in a toolbox.
| Size | Overall length | Model |
|---|---|---|
| 6" | 160 mm | İzeltaş 600011006 |
| 8" | 208 mm | İzeltaş 600011008 |
| 10" | 260 mm | İzeltaş 600011010 |
| 12" | 308 mm | İzeltaş 600011012 |
| 15" | 388 mm | İzeltaş 600011015 |
Selection criteria
- Largest nut: Find the wrench size (mm) of the largest nut you will turn and choose the length whose maximum jaw opening covers it. Confirm the maximum opening on the product page or in the manufacturer's data sheet.
- Force needed: Tight and rusted connections need a long handle; on small, delicate connections a long handle applies too much torque.
- Access: In tight compartments a short wrench with a slim head fits more easily.
- Handle: The product data of the İzeltaş wrenches in the catalog state chrome vanadium steel, chrome plating and a PVC-coated handle. The PVC coating is for grip and gives no electrical insulation. Live work requires a 1000 V insulated tool to IEC 60900.
Correct use and common mistakes
- Leaving play in the jaw: If the jaw is not closed fully onto the nut, the nut's corners get rounded off.
- Loading the movable jaw: Hold the wrench so that the pulling force goes onto the fixed jaw, which is one piece with the body.
- Extending the handle with a pipe or hitting it with a hammer: This strains the jaw and worm screw; use a larger size or a box-end wrench.
- Using it on pipe: A smooth-jawed adjustable wrench does not grip round pipe; a pipe wrench with toothed jaws is used for pipe.
- Working at one size all the time: If you keep tightening the same nut with high force, a box-end or socket wrench that fully encloses the nut is safer.
Standards
The product data of İzeltaş adjustable wrenches state TS ISO 6787 and DIN 3117; both are adjustable wrench standards.
Adjustable wrenches in the catalog
The Adjustable Wrenches category lists the 5 active İzeltaş products above, sold per piece (October 2026). Fixed-size wrenches are in Wrench Sets, wrenches for pipe in Pipe Wrenches, and sockets in Socket and Bit Sets.
Frequently asked questions
What does the inch value on an adjustable wrench mean?
The overall length of the wrench. For example, the 10" İzeltaş wrench is 260 mm long; the jaw opening is stated separately.
Which size of adjustable wrench should I buy?
For general maintenance, 8" or 10" covers most jobs. Choose 12" or 15" for large nuts and high torque, and 6" for tight spots.
What is the difference between an adjustable wrench and a pipe wrench?
An adjustable wrench has smooth jaws that grip the flats of a hex nut. A pipe wrench's toothed jaws bite into round pipe; used on a nut, they damage its corners.
Can an adjustable wrench with a PVC handle be used on live parts?
No. The PVC coating is for grip. Live work requires a 1000 V insulated tool made to IEC 60900.