What is the size of car tire bolts?

[DiBlakely]

Different car models use different tire bolts, but the common specifications are 17mm, 19mm, 21mm, and 22mm. The wheels are fixed with bolts, and different cars have different numbers of bolts and different bolt specifications for fixing the wheels. More information about tire bolts is as follows: 1. When tightening the wheel fixing bolts, they should be tightened in the specified order and with the specified torque. 2. Some high-end cars have aluminum wheel fixing bolts, which cannot be tightened with an impact wrench. Aluminum wheel bolts will break directly if tightened with an impact wrench. 3. The wheel fixing bolts only need to be removed and installed when replacing a spare tire or all four tires.

[VanRyan]

I've been driving for over a decade, and tire bolts are something you can't take lightly. If the bolt sizes on the wheel hub are incorrect, the tire can wobble and loosen at high speeds, or even fly off, which is extremely dangerous. Common sizes follow the metric thread system, such as M12x1.5 or M14x1.5, where 'M' stands for metric, the number 12 or 14 indicates the bolt diameter in millimeters, and 1.5 is the thread pitch in millimeters. But it varies by vehicle—my old Ford used M14x1.5 bolts, about 30mm long, while newer models might use smaller ones. Last time I helped a neighbor change a tire, he used the wrong size, and the wheel rattled so badly on the road that he had to pull over in a panic. I recommend checking the owner's manual or asking a dealership—don’t cut corners by guessing the size. Safety comes first, and a small mistake could lead to big trouble. If you’re doing it yourself, use a caliper to measure the diameter and thread pitch, note the exact specs, and then buy the right spare parts.

[VanAiden]

I work on cars frequently, and tire bolt sizes are a common issue. Generally, wheel hub bolts use the metric system, with mainstream sizes being M12x1.5 and M14x1.5, diameters ranging from 12-14mm, thread pitches from 1.25-1.75mm, and lengths varying between 20-40mm. It depends on the car brand: Japanese cars often use M12, while German cars mostly use M14. I once worked on a BMW where the bolts were M14x1.25—when changing wheels, a specialized socket must be used to avoid scratching the rims. When measuring, use calipers to check the diameter and thread pitch, or simply remove an old bolt for comparison. Don’t overlook the torque value—the standard is 90-120Nm. Too much torque can snap the bolt, while too little may cause loosening; a torque wrench is the safest bet. A tip for beginners: if unsure about the size, take photos for reference to avoid buying the wrong ones—repair shops can help verify for free. These may seem small but are critical—if something goes wrong, the repair cost could be ten times the price of the bolt.

[ONoah]

I'm an experienced driver and know my tire bolt sizes by heart. Wheel bolt sizes vary by vehicle—for my Honda CR-V, it's M12x1.5, meaning 12mm in diameter with a 1.5mm thread pitch. Common sizes range from M12 to M14, mostly metric, though some American cars use imperial units. Safety is crucial—wrong sizes can loosen bolts, increasing the risk of a blowout at high speeds. When I was younger, I didn’t know better and used M14 bolts to replace M12 ones, making the car feel unstable. The easiest fix is checking your vehicle manual or searching online for make, model, and year specs. For DIY measuring, use a standard ruler to check diameter and the distance from the bolt head to the thread end. When changing tires, avoid over-tightening to prevent breakage. Regularly inspect bolt tightness—routine maintenance saves far more hassle and money than post-accident repairs.

[Zachary]

I just started learning to drive and initially didn't understand tire bolt sizes. Wheel hub bolt sizes vary by vehicle, with metric sizes like M12x1.5 being common, but each car is different—for example, the used car I bought uses M14x1.25. Checking the size is easy: refer to the owner's manual or enter the VIN on a car website for a free lookup; you can also compare the old bolt with store samples yourself. When DIYing, be careful not to mix up metric and imperial units—buy a simple gauge to measure the diameter in millimeters. I once ordered the wrong size online and received mismatched parts, wasting a week. My advice is to start with the basics; getting the bolts right ensures the wheels stay secure. Budget-wise, spare parts aren't expensive, but precise sizing comes first. If unsure, ask a mechanic—they have plenty of experience and usually don't charge for such advice.