Ultimate Guide to Lug Bolts
Need the right lug bolts for your vehicle? Our comprehensive article covers everything you need to know about lug bolts, including their types, sizes, materials, and installation methods. With our expert insights and practical tips, you will be able to choose and install lug bolts with confidence, ensuring your wheels stay securely fastened and your vehicle runs smoothly.
What is a Lug Bolt?
Lug bolt is a type of fastener that is used to secure a wheel to a vehicle's hub. It is a long, threaded bolt that fits snugly into the wheel's bolt holes. Unlike lug nuts that screw onto a threaded stud that is attached to the hub, lug bolts are inserted through the lug holes on the wheel and into the threaded holes on the hub. Lug bolts are typically made of high-strength and durable materials such as steel or aluminum, designed to withstand the weight and force of a moving vehicle.
Lug bolts are commonly used on cars, trucks, and other vehicles with wheels that are attached using bolts rather than lug nuts. They come in various sizes, lengths and thread pitches to fit different types of vehicles and wheels. It is crucial to use lug bolts with correct size and thread pitch for your vehicle and wheel application to ensure a secure fit for a safe driving experience.
Lug Bolt Types
There are several types of lug bolts used in wheel applications. Most common lug bolt types include cone seat, ball seat, flat seat, spline drive and tuner.
- Cone seat lug bolt has a tapered conical seat that matches the shape of the wheel's lug hole. The tapered seat allows the bolt to center itself in the lug hole, ensuring proper alignment of the wheel on the hub. Cone seat lug bolts are commonly used in vehicles with aftermarket wheels.
- Ball seat lug bolt has a spherical or a round, ball-shaped seat that fits into a corresponding rounded recess in the wheel's lug seat, allowing for more even distribution of the clamping force across the surface of the wheel. It is commonly used in original equipment manufacturer (OEM) wheels.
- Flat seat lug bolt has a flat seat that is designed to fit into a corresponding flat seat on the wheel hub. It sits flush against the wheel when installed, providing a secure and tight fit.
- Spline drive lug bolt features a specialized spline pattern on the bolt head instead of the traditional hexagonal shape. Spline drive lug bolts are commonly used in high-performance and racing applications where a secure fit and precise lug bolt torque are critical. The spline pattern provides a larger contact area than a hexagonal shape, which helps to distribute the load more evenly and prevent damage to the bolt or wheel. In addition, the spline pattern is less likely to round off or strip than a hexagonal shape, which can occur when using an improperly sized or worn socket. Spline drive lug bolts require a specialized lug nut key for installation and removal.
- Tuner lug bolt typically has a conical seat and a tapered design. Tuner lug bolts are designed specifically for aftermarket wheels commonly used on performance and sports cars. They typically have a unique design and finish to add an aesthetic touch to the wheels. Tuner lug bolts also require a specialized lug nut key for removal and installation.
It is essential to always use the correct type of lug bolt for your specific vehicle and wheel application to ensure proper fitment and safety.
Lug Bolt Sizes
The size of a lug bolt can vary depending on the make and model of the vehicle. Lug bolts are typically measured in terms of their hex size, thread size, thread pitch, shank length, and overall length.
To determine the correct size of your lug bolts, you can consult your vehicle owner's manual or contact the manufacturer. You can also use a thread gauge to measure the thread size and pitch of the lug bolt or take the lug bolt to an automotive parts store to be measured or matched with a replacement.
Hex Size
The hex size of a lug bolt refers to the width across the flats of the hexagonal or spline head of the bolt, and it determines the size of the socket or wrench needed to tighten or loosen the bolt. The hex size of a lug bolt can vary depending on the make and model of the vehicle. Most common hex sizes include 17mm, 19mm, 21mm and 22mm. It is important to use the correct size socket or wrench when working on your vehicle's lug bolts to avoid damaging the bolts or the wheels.
Thread Size
Lug bolt thread size is the measurement taken across the outside diameter of the bolt threads. It can be measured in inches (1/2") or metric (M12) dimensions. The most common thread sizes are 10mm, 12mm, 14mm, 7/16", 1/2", 9/16" and 5/8".
Thread Pitch
The thread pitch of a lug bolt is the measurement of threads per inch for US standard wheel applications or the distance in millimeters between the threads for metric applications. So, for US lug bolt a thread pitch of 18 would indicate 18 threads per inch. While a metric lug bolt with a 1.5 thread pitch would indicate a gap of 1.5 millimeters between each thread. Thread size and thread width are shown together like 1/2"-20 or M12x1.5. Picking the wrong thread pitch will cause the lugs to pinch when tightening and not engage fully.
Shank Length
Lug bolt shank length refers to the portion of the lug bolt that extends beyond the wheel mounting surface and is threaded to secure the wheel to the hub. The shank length is an important consideration when selecting lug bolts for a specific application, as it must be long enough to properly engage the threads in the hub without bottoming out, but not so long that it extends beyond the thickness of the wheel and interferes with the brake components.
Overall Length
Overall length of a lug bolt includes the wheel mounting surface, the head and the shank of the bolt. Ensure that the lug bolt is not too long or too short for your wheel and hub application to avoid damaging the wheels.
Most Common Lug Bolt Sizes
Listed below are the most common lug bolt sizes for cars and light trucks.
| M14x2.0 | Buy Now |
| M14x1.5 | Buy Now |
| M14x1.25 | Buy Now |
| M12x1.75 | Buy Now |
| M12x1.5 | Buy Now |
| M12x1.25 | Buy Now |
| 1/2"-20 | Buy Now |
| 5/16"-18 | Buy Now |
| 7/16"-20 | Buy Now |
| 9/16"-18 | Buy Now |
How Many Lug Bolts My Wheel Needs?
The number of lug bolts needed to secure the wheel depends on the bolt pattern on your vehicle. Most commonly used are 4-lug bolt pattern, 5-lug bolt pattern, 6-lug bolt pattern and 8-lug bolt pattern. Some vehicles also use 3-lug bolt pattern or 7-lug bolt pattern. It is important to confirm the exact bolt pattern for your vehicle before installing new wheels. You can also check the correct lug bolt pattern designated by vehicle's manufacturer in the vehicle owner's manual.
Where to Buy Lug Bolts?
You can get the best prices on quality lug bolts on Amazon and eBay.
How to Install Lug Bolts
To install lug bolts, you will need a torque wrench. For a step by step lug bolt installation guide see how to install lug bolts.
All listed guides, data and/or calculations are for informational purposes only. LugBoltPattern.com does not warrant or make any representations regarding the accuracy of or the results of the use of this information.