Automotive replacement bolts are critical components for maintaining the integrity and safety of a vehicle, spanning applications from engine compartments to body panels. Selecting the correct bolt type, material, and size is paramount for secure fastening and preventing future issues. Products were evaluated based on material grade, assortment versatility, application specificity, user reviews, and feature analysis.
mankk 400PCS Metric Grade 10.9 Flange Bolts and Nuts Assortment Kit M6x1.0, M8x1.25, M10x1.5 (12mm to 45mm) Black Alloy Steel Class Hex Bolts and Nuts Washers Kit for Automotive
This kit offers a comprehensive range of high-grade metric flange bolts, nuts, and washers, suitable for diverse automotive repair scenarios.
Search on AmazonBesitu 280Pcs Metric Flange Bolt Assortment, M6x1.0, M8x1.25, M10x1.5 (12mm to 30mm) Assorted Hex Bolts and Nuts Washers Kit for Automotive, 10.9 Black Zinc Galvanized
Providing a substantial assortment of common metric flange bolts with a robust 10.9 alloy steel construction, this option delivers significant value.
Search on AmazonGM Genuine Parts 11610633 Starter Bolt
As an OEM part, this starter bolt is engineered and tested to rigorous standards, ensuring an exact fit and performance for specific GM vehicles.
Search on AmazonLooking for the best Automotive Replacement Bolts?
Discover now our comparison of the best Automotive Replacement Bolts. It is never easy to choose from the wide range of offers. On the market, you will find an incalculable number of models, all at different prices. And as you will discover, the best Automotive Replacement Bolts are not always the ones at the highest prices! Many criteria are used, and they make the richness and relevance of this comparison.
To help you make the best choice among the hundreds of products available, we have decided to offer you a comparison of the Automotive Replacement Bolts in order to find the best quality/price ratio. In this ranking, you will find products listed according to their price, but also their characteristics and the opinions of other customers. Also discover our comparisons by categories. You won’t have to choose your products at random anymore.
- 【Metric Flange Bolt Assortment】This is nice selection of metric flange head bolts of the most common lengths along with the nuts and washers, Including M6-1.0 x 12/16/20/25/30mm, M8-1.25 x 16/20/25/30mm, M10-1.5 x30mm, 280pcs in total. The fully...
- 【10.9 Alloy and Black Galvanized】This flange bolt kit is crafted from 10.9 grade alloy steel with a durable black galvanized finish. If you're working inside the engine, you'll need high-strength Class 10.9 bolts on hand. Class 8.8 bolts are not rated...
- 【Time & Money Saver】Great bins for storage with a size chart on the inside and outside. Compared to the time it takes to go to a hardware store and the cost of buying individual packs, this flange bolts nuts washers kit is a time and money saver.
- 【Wide Applications】The flange has serrations grip that increases the torque needed to loosen the bolt, which is perfect for mounting something that exposed to vibrations and harshness during action. Widely used in home improvement, automotive projects...
- 【Reusable Container】Everything is sorted in separate compartments that are labeled, which is nice when you're looking for a specific size. You can also reuse the plastic container after you've used all the flange bolt kit. The quintessential toolbox...
- 【High Quality Materials 】Flange bolts are made of 10.9 grade alloy steel with galvanized surface and high strength, which is very suitable for working inside the engine.
- 【Product Features】Including two thread designs: full thread and half thread, to ensure stability and safety and meet different requirements. Metric flange head bolts, nuts and washers with the most common sizes can fully meet your needs.
- 【Wide Application】Flange bolts are widely used in many industries, such as building structures, automobile industry, industrial equipment, mechanical equipment and so on.
- 【Easy to Use 】The are placed in a handheld box plastic box, each size of Flange bolts are sorted separately which is easy to transport and distinguish.There are classified notes in the box for easy distinction.
- 【Package Include 】A total of 400 PCS metric flange bolt Kits,17 different sizes flange bolt,Includes 100PCS flange screw, 100PCS nut, 100PCS gasket, 100PCS elastic sheet,enough replacement to suit your needs.
- 【Multi-purpose and portable box】The flange bolts are packed in a multi-purpose and portable tool box with a movable divider for easy distinction. After use, other products can be stored and reused.
- Compatible Models: This self tapping screw assortment kit is compatible with Audi models, including but not limited to: Audi A3/A4/A5/A6/A7/A8/Q3/Q5/Q7/Q8/R8, etc. Ensure a wide range of applications to meet the needs of different car models
- Premium Material: This set of automotive trim screws is made of high quality carbon steel with galvanized material, which is sturdy and durable, with excellent corrosion resistance and high temperature resistance, ensuring stable use in various...
- Not Easy to Fall Off: The auto interior screw opening is designed with deep and even torque to ensure that it is firm and not easy to fall off after tightening. After rigorous engineering design, they are suitable for long time use and not easy to loosen...
- Total Package: In this kit, you will get 160 pieces and 14 sizes of metal automotive screws and retaining clips, covering 14 popular specifications. The abundant quantity meets daily needs and is suitable for various occasions
- Widely Used: These metal car screws and bolts are extremely practical accessories, widely used in splash guards, fender liners, bumper covers, air ducts and plastic trims, etc., to help with daily maintenance and repair of your vehicle and ensure that...
- [Packing List] You will receive 20pcs fender screws, sufficient quantity and long service life.
- [Size] Screw Size: M4.8-1.61 x 19mm (#10 x 3/4”), Phillips Truss Head, Washer Outer Diameter: 16mm (5/8”), very convenient to carry, does not take up too much space, and brings great convenience to your driving.
- [Compatible]Replace#90114-SE0-000,90114-SZ3-000,90114SE0000,90114SZ3000, meets or exceeds OEM specifications.
- [Product Design] Fender liner screws adopt cross slot design screws, which are easy to install and do not require additional tools. They can directly replace old fasteners and are very suitable for your car.
- [Essential Tools] Bumper Cover Fender Liner Screw is easy to install and fasten quickly without complicated installation steps. It has a compact and stable structure and is an ideal replacement part for original equipment. Please check the size of the...
- FEL-PRO ES 72310 Engine Cylinder Head Bolt Set for Volkswagen Jetta
- COMPATIBILITY – Fits 2009-2013 Audi A3 Quattro; 2013-2013 Audi allroad; 2013-2013 Audi A4 allroad; 2009-2014 Audi TTS Quattro; 2006-2009 Audi A3; 2010-2013 Audi A3; 2010-2013 Audi A5 Quattro; 2011-2013 Audi Q5; 2010-2013 Audi A5; 2012-2013 Audi A...
- GET THE RIGHT PART -- Before purchasing, research to ensure that the part will fit your vehicle; enter all vehicle information (year, make, model, engine and trim) for compatibility and check qualifier notes
- Meets or exceeds all original equipment specifications
- Application specific design to ensure a perfect fit
- Validated for fit, form and function
- 【Package Contains】: This screw and nut clip kit contains 20 pcs body bolts with built-in fenders, 20 pcs u-clips, 20 pcs screws, 20 pcs gold u-clips, 20 pcs plastic push clips. The quantity is sufficient to meet your usage needs.
- 【Quality Material】: This screw u-nut kit is made of high-quality nylon and high-hardness steel, with excellent compressive strength, toughness, abrasion resistance, corrosion resistance, and long service life.
- 【Fine Design】: These under-engine cover splash shield body bolts adopt a U-shape fixing structure, providing good tightness to ensure a safe and solid connection, not easy to loosen or fall off, giving you a better driving experience.
- 【Easy Installation】: These car's screws and bolts don't need to be pre-punched, just use the basic tools to tighten and fix the screws and nuts, save your installation time, and use it more efficiently.
- 【Widely Used】: These bumper cover wing fasteners ensure they meet the most common fastening requirements in vehicle maintenance and repair, suitable for under the bonnet, splash guard, fascia, grille, side skirts, and splash guard retainers.
- 【Screw and Nut Clip Kit】: You will receive automotive metal bolts (20 pcs), U-shaped Clamps (20 pcs), automotive metal screws (20 pcs), Gold U-shaped clamps (20 pcs), automotive plastic clips (20 pcs). The quantity is enough to meet your various...
- 【High-Quality Materials】: The car bumper screws are made of premium metal, and the U-clips are galvanized to ensure durability and resistance to wear, rust, and oxidation. They are sturdy, not easily deformed, broken, or bent
- 【U-Shaped Support Base】: The set features U-shaped brackets that enhance installation sealing, prevent screws from falling off, increase safety, reduce screw waste, and offer a sleek and practical design that perfectly matches your vehicle
- 【Easy Installation】: The screws and nut clips are crafted with excellent workmanship, featuring a one-piece molded design for secure connections and reduced slippage during installation. The deep, clear threads ensure a high bite, making installation...
- 【Wide Application】: These car clamps are suitable for securing various objects in appropriately sized holes. The self-tapping screws provide firm fastening and a strong hold without the need for pre-drilling. Ideal for securing car panels, bumpers...
- 🌷Premium Quality Materials: Our differential cover bolts are crafted from high-strength carbon steel used for any differential requiring M8-1.25x20mm bolts, guaranteeing exceptional reliability and long-lasting performance under rigorous conditions...
- 🌷Precision Engineering: Each rear differential cover bolt is meticulously engineered to exact specifications, guaranteeing a perfect fit and secure attachment to both the differential cover and housing. This precision guarantees optimal alignment and...
- 🌷Secure and Durable Fastening: Featuring robust design and 1.25mm pitch, our diff cover bolts deliver a strong grip that effectively secures the differential cover in place. This avoids any risk of loosening during operation, safeguarding against...
- 🌷Effective Sealing Performance: Properly tightened, our differential gasket bolts maintain a tight and reliable seal between the differential cover and housing. This sealing integrity against leaks of differential fluid, crucial for maintaining optimal...
- 🌷User-Friendly Installation: Designed with ease of installation in mind, our bolts with 10mm hexagonal opposite side length are suitable for standard tools. This simplifies the assembly process, guaranteeing hassle-free installation for automotive...
- OEM Numbers: Our car engine splash guard bolts can be replaced by OEM numbers are N623332-S100, W5220822-S426, N623332-S2, W520802-S439 (compatible with Ford), 11503716, 12337917, 1016937, 11503714, 11503957 (compatible with GM). Please double check the...
- Important Size: We have a total of hex bolts*25 and spacers*25 in our package for you, the specification of M6 bolt is M6-1.0 x 25 mm, the diameter of the spacer is 0.77 inch/19.5 mm, the diameter of the bolt's hex head is 0.39 inch/10 mm, please check...
- Provide Tightening Effect: Our car engine splash shield bolts with high precision threads are adapted to the need of replacing old and worn out bolts, providing reliable tightening effect, they are essential accessories for automotive repairs
- Application Scenario: Our car 10 mm bolts have a rounded and unthreaded end, which can avoid the nut from falling off when used with nuts, and are especially suitable for fixing many key parts of the car such as bumpers, mudguards, splash guards...
- Sturdy and Durable: The use of carbon steel galvanized as the main material of the car rear bumper bolts, giving the bolts good structural strength and structural stability, durable, not easy to fracture, deformation and other problems, can be used for a...
- [Set Includes]The set includes 20 GM screws in sufficient quantity to meet your daily replacement and repair needs.
- [Product Name] Other Names: U-shaped Nut for Door Decorative Panel, Bumper Cover Nut, Wheelhouse Lining Nut, Wheelhouse Lining U-shaped Nut, Fender Lining U-shaped Nut, Grille Nut, Air Deflector U-shaped Nut, External Fuel Filler U-shaped Nut; Rear air...
- [High Quality materials]The bumper cover splash shield bolts are made of high-quality materials, which are wear-resistant and corrosion-resistant. They are not easy to break or crack during use and are durable.
- [Specification] Screw size: M4.2-1.41, 7mm hex head, loose washer, 17mm outer diameter.
- [Specification] Screw size: M4.2-1.41, 7mm hex head, loose washer, 17mm outer diameter.
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Last update on 2026-03-24 / Affiliate links / Images from Amazon Product Advertising API
How to Choose the Best Automotive Replacement Bolts
Material Grade and Finish
The material grade of automotive replacement bolts dictates their strength and suitability for specific applications. For instance, kits like the mankk 400PCS Metric Flange Bolts and Besitu 280Pcs Metric Flange Bolt Assortment prominently feature Grade 10.9 alloy steel. This high tensile strength material is typically required for critical connections, such as engine mounts or suspension components, where significant stress is encountered. In contrast, components like those in the LAINLOY 100PCS Automotive Screws and Bolts kit incorporate high-hardness steel alongside nylon for less load-bearing applications like splash shields or fender liners. The finish is also crucial; galvanized or black zinc galvanized surfaces, as seen with mankk and Besitu, provide enhanced corrosion resistance, which is vital in automotive environments exposed to moisture and road salts.
Assortment Versatility vs. OEM Specificity
Choosing between a general assortment and an original equipment manufacturer (OEM) specific part depends entirely on the repair task. Comprehensive kits from brands like mankk and Besitu offer a wide array of common metric sizes (M6, M8, M10) and lengths, making them highly versatile for general repairs or stocking a workshop. These kits often include both full and half thread designs, allowing for application-specific stability. However, for critical components like a crankshaft pulley bolt (Ford F5RZ6A340B) or a starter bolt (GM Genuine Parts 11610633), an OEM part is often preferred. These are designed and tested to exact vehicle specifications, ensuring precise fit, material composition, and performance that aftermarket assortments may not replicate.
Thread Design and Application
The specific thread design of a bolt can significantly impact its performance and suitability. Some kits, like the mankk assortment, explicitly state the inclusion of both full-thread and half-thread designs. Full-thread bolts offer maximum grip along the entire engaged length, often preferred for thinner materials or when maximum clamping force is needed. Half-thread (or shoulder bolt) designs typically provide a smoother, unthreaded shank that can act as a pivot or spacer, which is beneficial in applications where shear strength or precise alignment is required. Flange bolts, characteristic of the mankk and Besitu kits, integrate a washer-like flange under the head, distributing the clamping load over a wider area and often negating the need for a separate washer.
Accompanying Components and Organization
Beyond the bolts themselves, the presence and quality of accompanying components and storage solutions can enhance the utility of a kit. Assortments from mankk and Besitu typically include matching nuts and washers, ensuring a complete fastening solution. The Besitu kit, for example, is noted for its organized bins with size charts, which users report significantly saves time during repairs. Conversely, kits like LAINLOY's focus on a mix of fasteners, including U-nuts and plastic retainers, catering to specific body panel and splash shield applications where a variety of fastener types are commonly used together.
Pros & Cons
mankk 400PCS Metric Grade 10.9 Flange Bolts and Nuts Assortment Kit M6x1.0, M8x1.25, M10x1.5 (12mm to 45mm) Black Alloy Steel Class Hex Bolts and Nuts Washers Kit for Automotive
Pros
- Features high-strength Grade 10.9 alloy steel construction for critical applications.
- Includes a large 400-piece assortment covering common M6, M8, M10 metric sizes and lengths.
- Offers both full-thread and half-thread designs to accommodate various stability and safety requirements.
- Galvanized surface enhances corrosion resistance, prolonging bolt life in harsh environments.
Cons
- Being an assortment, it may not contain highly specialized sizes or OEM-specific bolts.
- The sheer number of pieces might be excessive for individuals with minimal repair needs.
Besitu 280Pcs Metric Flange Bolt Assortment, M6x1.0, M8x1.25, M10x1.5 (12mm to 30mm) Assorted Hex Bolts and Nuts Washers Kit for Automotive, 10.9 Black Zinc Galvanized
Pros
- Constructed from durable 10.9 grade alloy steel with black galvanized finish for strength and corrosion resistance.
- Comes in an organized storage bin with a size chart, which users find practical for quick identification.
- Provides a good selection of common M6, M8, M10 flange bolts, nuts, and washers for general automotive use.
Cons
- The 280-piece count is less comprehensive than some larger assortments, potentially limiting very extensive repairs.
- Does not explicitly mention different thread designs (full/half thread) like other kits.
100PCS Automotive Screws and Bolts, Car Body Bolts for Engine Under Cover Splash Shield Guard, Fenders Liner Push Retainer Auto Bumper Clips, Plastic Rivet Fasteners U-Nuts Kit
Pros
- Offers a specialized mix of body bolts, u-clips, and plastic rivets for specific body panel and under-engine cover applications.
- Materials combine high-quality nylon and high-hardness steel, suitable for designated uses like splash shields.
- U-shape fixing structure provides good tightening for secure attachment of components.
Cons
- Primarily designed for body and trim fasteners, it is not a direct replacement for structural metric bolts.
- The included bolt types and sizes are very specific and lack the versatility of general metric bolt assortments.
Common Mistakes to Avoid
Incorrect Material Grade Selection
A frequent error involves substituting a bolt of an insufficient material grade for a critical application. For instance, using a standard bolt where a Grade 10.9 alloy steel flange bolt (as found in mankk or Besitu kits) is specified can lead to premature failure under stress, risking safety and component damage. Always verify the required grade for the specific automotive component.
Disregarding OEM Specifications for Critical Parts
Assuming a generic bolt from an assortment will suffice for every application is a common pitfall. For components like the Ford F5RZ6A340B Engine Crankshaft Pulley Bolt or the GM Genuine Parts 11610633 Starter Bolt, OEM parts are engineered to precise tolerances, material composition, and sometimes unique thread pitches or lengths. Using an aftermarket bolt that doesn't perfectly match these specifications can result in improper fit, stripped threads, or component malfunction.
Overlooking Thread Design and Length Requirements
The distinction between full-thread and half-thread bolts, as highlighted by the mankk kit, is often overlooked. Using a full-thread bolt where a half-thread (shoulder) bolt is needed for shear strength or precise alignment can lead to inadequate clamping or improper component movement. Similarly, using a bolt that is too long risks bottoming out before achieving proper torque, while one that is too short may not provide sufficient thread engagement.
Neglecting Specialized Fastener Types
Focusing solely on traditional hex or flange bolts can lead to issues when dealing with vehicle bodywork or interior panels. Kits like the LAINLOY Automotive Screws and Bolts demonstrate that many automotive applications require specialized fasteners such as U-nuts, plastic rivets, or integrated fender bolts. Attempting to force a standard bolt into a location designed for these unique components often results in damage to the panel or an insecure attachment.
