Automotive Manufacturing: Studs or bolts? The key to the car’s functionality is the decision about whether to use custom head studs or head bolts. Although bolts and screws are similar in their functions, they each have their own unique characteristics, advantages, and drawbacks.
For the car’s overall functionality, it is important to choose whether to use either a head bolt or a stud. Although bolts and screws are considered fasteners, they serve similar functions. However, each has its own set of benefits. Let’s take a look at the key differences between bolts & studs.
Differential ties between Studs and Bolts
Overall Appearance
The Studs will be easily recognized by fully threaded ends with an unthreaded central section. Bolts are long shafts with only a partial thread. Bolts require a nut to increase tension between the parts they hold together. The bolt however has a flat head on one end. The technician will need a wrench or a screwdriver to increase or decrease the tension in the bolt-fastened assembly.
Design of Head
Bolts generally have one pointed end, which allows engineers to fasten them into the material in the same manner as a screw. To fulfill its purpose efficiently, the fastener doesn’t need a washer or a nut. A stud can be attached to one end of its stud to fulfill the same function.
Strength
Bolts and Studs both undergo a thermal treatment to increase their structural strength. The difference is that studs can have their strength increased by either undergoing additional heat treatment or a roll thread process. Note that studs subject to heat treatment have higher stress tolerance and mechanical strength, making them ideal for heavy-duty applications.
Role in Engine Assembly
One of the most striking differences between bolts and nuts is their function in the engine assembly. For a nearly perfect alignment between the head gaskets and the cylinders, high-end studs can be used that have been designed for precise tolerances. Studs are much easier and more convenient for designing an engine.
Engineers say bolts make disassembling, replacing parts, and repairing engines easier. One component can be fixed with a bolt to remove the engine. It is therefore preferable that vehicles with large cylinders run down to the engine compartment be secured by bolts.
Torque
The clamping force used by tightening to secure a stud in place can usually be applied without any additional effort. Direct clamping force is required when the stud is secured against the nuts. This results in even torque distribution, increased reliability, and a lower chance of gasket failure.
Bolts, on the other hand, need to be rotated with a wrench or screwdriver. The fastening process, regardless of the tool used, provides a vertical clamping and twisting force. This will allow the fastener to after the accumulation load to stretch out and twist. Because the bolt has to respond to two different forces, its ability to keep the head of the gasket in place is limited.