Why Wheel Studs Break Off

Why Wheel Studs Break Off

In this post, we’ll cover why they break off and what you can do to avoid it from happening. KSP Performance is always here to provide an assessment backed by experience and expertise.

Stud Quality Issues

The biggest reason you need to make sure you’re getting high-quality wheel studs is to ensure driver safety. If there is no strict quality control, any error in production will cause sub-standard bolt production which can lead to catastrophe.

KSP can tell you the quality of your bolts by its product description and appearance. From raw materials and surface finish to thread processing and mold design (which can’t be determined from the surface). These are the areas that can cause stud break-off or thread-off.

1. Surface Treatment

Grey/white Geomet (Dacromet) is a better surface treatment than zinc or electronic plating. Geomet surface treatment increases the stud’s resistance to rust and corrosion while increasing its strength.

2. Material

You’ll find that most sellers use 40Cr, however 40Cr doesn’t reach the 10.9 standard grade for studs. Only SCM435 (or higher performing materials) can meet the standard.

Contrary to what it might seem, wheel studs become more fragile when hardness increases. That’s why 10.9 is the standard. This grade is perfect blend of hardness and toughness to prevent stud break-off.

Trust that KSP uses SCM435 grade 10.9 bolts on wheel spacers.

Other Major Issues That Lead to Stud Break-Off

At times, if you test a broken lug bolt, you can find that it meets the standard quality. Yet it still breaks. So, why do lug bolts break if they are made with the proper material and quality assurance?

1. Installation

When installing wheel spacers, bolts may not be tightened according to the recommended torque. Some customers use impact wrenches to install or disassemble spacers.
If the direct of force is incorrect, then the wheel stud can break off while driving or disassembly.

2. Wheel Hub

If the wheel hub is dirty or not flat, or if the wheel spacer is not re-torqued after 50-100 miles of driving, the bolts can break off. In these scenarios, the wheel spacer is loose and the stress to the studs is uneven.

3. Spacer Machining

If the design or the machining of the aluminum spacer is poor, it will lead to a lateral extrusion force on the bolt (This is called shear force), which will more than likely lead to stud break-off after driving.

4. Lug Nuts

Many people equip wheel hubs with after-market lug nuts. Some of these lug nuts are not quality-assured, which leads to the bolts snapping off due to the incorrect direct of force. Even more, the stud’s thread is stripped.

5. Impact

If the wheel hub was impacted by a strong external force and was not checked or repaired, it can lead to stud break-off.

Wrapping Up

Poor stud quality isn’t the only reason studs break off, though it is still a valid reason. Suppliers need to provide wheel spacers with higher quality studs and customers need professional installation to avoid break-off.

KSP Performance provides custom 10.9 grade studs to ensure quality exceeds OEM standard. We also use SCM435 alloy steel, the OEM heat treatment, Dacromet surface treatment, professional design/processing, and strict quality control.

Customer safety is always our top priority. KSP is a supplier you can trust.