Most Asked BIW Fixture Design Interview Questions and Answers

Body in White (BIW) is a term that refers to the basic body of the car, which includes the doors, hooks, and deck lids, before the addition of the chassis, powertrain, and trim-level features like windscreens, seats, upholstery, electronics, etc. At the most basic level, BIW offers the necessary shape and structure for incorporating the aforementioned additional factors.

Are you considering a career as a BIW Design Engineer, or have you already begun and are preparing for the next step? If you want to land your dream in the core industry, you need to be aware of the expected interview questions. As a successful BIW design engineer in India, you can earn up to ₹7,00,000 annually. 

Read and understand some of these often-asked BIW sheet metal interview questions before approaching you next interview.

10 BIW Fixture Design Interview Questions 

In this section, we have jotted down the most common BIW design interview questions. We hope this will help you along your journey of preparation.

 

• Why are Allen bolts sometimes chosen over hexagonal bolts?

 

Allen bolts have one major advantage over hex bolts: the tool required to tighten them can be smaller than the head. Therefore, they are ideal if you have a bolt recessed inside a small aperture. The Allen key can be inserted into the hole to tighten the bolt.

They resemble flathead or Phillips screws, which also need a screwdriver. However, because an Allen bolt or screw has a significantly larger surface area, the hole is less likely to be stripped out.

You can use hex bolts in tight locations if you have an extension rod for your socket driver. But to accommodate the socket, you'll still need more space around the hex head.

 

• Describe spot welding

 

One of the earliest methods of joining two or more sheets of metal together is spot welding, a type of resistance welding in which no filler material is used.

Using shaped alloy copper electrodes that conduct an electrical current through the weld pieces, the procedure entails applying pressure and heat to the weld region. When the material melts and fuses the components together, the current is cut off, the electrodes' pressure is maintained, and the liquid "nugget" solidifies to create the joint.

 

• Why is it vital to measure the weld nugget?

 

All resistance welding enterprises must measure weld nuggets as part of their quality control process. A nugget's strength is generally considered adequate if its average diameter falls within the permitted range (which changes based on the metals being welded). 

The method of measuring the weld nugget's diameter may highlight irregularities or problems with the welding procedure. Additionally, it can be a symptom of potential future problems such as electrode wear, conductor wear, or loose connections. Electrode wear happens as a result of electrical arching ablating the metal surface and fluorine continuously passivating the electrode surfaces.

The electrode's composition is crucial (many electrodes are made of solid brass or a mix of brass and other metals), and different alloys are employed for their low erosion properties.

 

• Why is shimming necessary while designing a BIW fixture?

 

The workpieces become heated during the welding process. Due to the heat, the product being welded together can shrink or move. 

And it is difficult to provide a tight joint even during welding. Shimming is a process of inserting thin sheet metal to establish a tight joint.

 

• When should we prefer a diamond locating pin over a round pin?

 

When placing a diamond locating pin, it's essential to consider the contact surfaces' orientation. If a vital measurement for your assembly needs to be maintained, place the diamond locating pin in this position.

When the central axes must be aligned but the rotation of the parts is not crucial, diamond locating pins can also be utilised for concentric parts. It will be ideal for installing three diamond pins on a circle centred on the part with the contact surfaces aligned radially. The pieces' two centres will then be coaxial; however, they can be gently rotated to facilitate assembly.

 

• Is aluminum difficult to weld?

 

When welding aluminum, you may face several challenges, including:

• Exceptional Thermal Conductivity: Due to the higher heat input needed due to the excessive heat dissipation, this might make welding challenging and/or cause unintended distortion of the pieces.
• Solubility of Hydrogen: Due to the high solubility of hydrogen in molten aluminum, processing involves hydrogen absorption in the weld pool. The hydrogen bubbles are trapped as the liquid material hardens, resulting in porosity.
  

 

• Explain the functionality of toggle clamps

 

Toggle clamps are adaptable work-holding devices that lock a stationary workpiece. This is particularly helpful for applications like injection molding, production lines, welding, etc.

Toggle clamps are quick-action clamping devices that work on the "toggle action," an over-center locking mechanism. The clamping handle moves a linkage to its centre position using a system of levers and pivots. After that, the clamping arm meets the centre to secure the fixture or workpiece.

 

• What do we mean by car lines in BIW?

 

Car lines or grid lines on the fixture that correspond to the same spot display the coordinates at the corner. These lines make it simple to understand the position in BIW.

Sometimes the fixture has a single coordinate hole representing the vehicle line coordinates. Using that reference point, the fixture can be created and checked. Near the hole, body coordinates are mentioned.

 

• What is hemming in automotive production?

 

The edges of the sheet are curled or folded across another region during the hemming procedure to achieve a snug fit. Hemming procedures are typically used to join components together, enhance a part's appearance, and reinforce part edges.

For this assembly, hoods, doors, trunk lids, and fenders are typical components.

 

• Why is it difficult to join aluminium to steel?

 

Typically, steel melts at roughly 1370°C, which is more than twice as hot as aluminum, which melts at about 660°C. And in the molten state, these two metals are completely insoluble with each other. Instead of fusing, they become a brittle intermetallic compound. 

Conclusion

We have discussed a few BIW interview questions and answers often asked to candidates appearing for interviews. If you want to save time in preparing for an interview, enroll in Skill-Lync’s PG program in BIW fixture. We equip you with new-age technologies and offer placement training and job assistance.