Metric Flange Hex Bolt & Nut Assortment — 292-Piece Class 10.9 Black Alloy Steel Kit
When a stripped bolt or missing fastener stops your project cold, you need a reliable kit on hand. This 292-piece metric flange hex bolt assortment is built for automotive technicians, machinery operators, and serious DIYers who can't afford downtime. Every fastener in this set is rated Class 10.9 — one of the highest strength grades available for metric hardware.
The set covers M6, M8, and M10 thread diameters across multiple lengths (12mm to 30mm), paired with matching flange nuts, flat washers, and lock washers — all finished in black oxide for corrosion resistance. The complete kit ships in a clear plastic organizer case measuring 19.5 × 13 × 3.6 cm (7.67 × 5.11 × 1.41 in), keeping every piece sorted and ready to grab.
From tightening engine brackets and motorcycle frames to securing lawn equipment, metal fabrication, and structural woodworking, this assortment covers the most common metric fastener scenarios in a single organized box.
✅ Compatible with M6, M8, and M10 metric applications — automotive, machinery, industrial equipment, and general DIY assembly.
Key Features
- 🔩 Class 10.9 high-strength alloy steel construction — engineered for demanding mechanical and structural applications where standard-grade fasteners fall short
- 🖤 Black oxide finish provides corrosion resistance and a clean, professional appearance across all 292 pieces
- 🔧 Flange hex head design distributes clamping load over a wider surface area, reducing the risk of loosening under vibration
- 📦 292-piece complete assortment includes flange bolts, flange nuts, flat washers, and lock washers — everything needed for a secure, complete fastening system
- 📐 Covers M6, M8, and M10 thread sizes with lengths from 12mm to 30mm — the most frequently needed metric sizes for automotive and machinery work
- 🗂️ Organized plastic storage case (19.5 × 13 × 3.6 cm) keeps all pieces sorted by size for fast access on the job or in the shop
What's in the Box
| M6 × 12mm Flange Bolts |
12 pcs |
| M6 × 16mm Flange Bolts |
9 pcs |
| M6 × 20mm Flange Bolts |
8 pcs |
| M6 × 25mm Flange Bolts |
6 pcs |
| M6 × 30mm Flange Bolts |
5 pcs |
| M6 Flange Nuts |
40 pcs |
| M6 Flat Washers |
40 pcs |
| M6 Lock Washers |
40 pcs |
| M8 × 16mm Flange Bolts |
10 pcs |
| M8 × 20mm Flange Bolts |
10 pcs |
| M8 × 25mm Flange Bolts |
6 pcs |
| M8 × 30mm Flange Bolts |
5 pcs |
| M8 Flange Nuts |
31 pcs |
| M8 Flat Washers |
31 pcs |
| M8 Lock Washers |
31 pcs |
| M10 × 30mm Flange Bolts |
2 pcs |
| M10 Flange Nuts |
2 pcs |
| M10 Flat Washers |
2 pcs |
| M10 Lock Washers |
2 pcs |
Who Is This For
🚗 Automotive & Motorcycle Technicians — Tighten engine brackets, body panels, exhaust components, and frame hardware with confidence. Class 10.9 strength handles the torque demands of vehicle assembly and repair.
🔧 Machinery & Equipment Maintenance — Keep lawn mowers, compressors, and industrial equipment running with a ready supply of the most common metric fastener sizes. No more last-minute hardware store runs.
🏗️ Metal Fabrication & Structural Assembly — Flange bolts and matching lock washers are ideal for structural joints where vibration resistance and load distribution matter.
🪵 DIY Home & Workshop Projects — From deck hardware to workshop fixtures, this assortment covers the metric fastener needs of serious home builders and weekend project enthusiasts.
Technical Specifications
| Total Pieces |
292 |
| Strength Grade |
Class 10.9 (High Strength) |
| Material |
Alloy Steel |
| Finish |
Black Oxide |
| Head Type |
Flange Hex |
| Thread Type |
Metric Coarse |
| Thread Sizes Included |
M6, M8, M10 |
| Bolt Lengths Included |
12mm, 16mm, 20mm, 25mm, 30mm |
| Included Hardware Types |
Flange Bolts, Flange Nuts, Flat Washers, Lock Washers |
| Package Dimensions |
19.5 × 13 × 3.6 cm (7.67 × 5.11 × 1.41 in) |
| Product Weight |
1328 g (2.93 lb) |
Frequently Asked Questions
What thread sizes are included in this set?
This set includes M6, M8, and M10 metric coarse thread fasteners. It does not include M4, M5, or M12 sizes. Each size comes with matching flange nuts, flat washers, and lock washers.
What does Class 10.9 mean for bolt strength?
Class 10.9 is a high-strength metric bolt grade. The first number (10) indicates a minimum tensile strength of 1000 MPa, and the second number (9) indicates the yield strength is 90% of tensile strength. This makes Class 10.9 bolts suitable for high-load mechanical and automotive applications.
Are lock washers included in this set?
Yes. The set includes lock washers for M6, M8, and M10 sizes, along with flat washers and flange nuts. This gives you a complete fastening system for each bolt size without needing to source additional hardware.
Is the black oxide finish rust-proof?
Black oxide provides corrosion resistance and is suitable for indoor and sheltered outdoor use. For prolonged exposure to moisture or harsh outdoor environments, applying a light coat of oil or using additional protective measures is recommended.
Does the flange head replace the need for a separate washer?
The integrated flange distributes clamping load and can reduce the need for a flat washer in many applications. However, this set also includes flat washers and lock washers for situations where additional load distribution or vibration resistance is required.
What is the storage case like?
The set comes in a clear plastic organizer case measuring 19.5 × 13 × 3.6 cm (7.67 × 5.11 × 1.41 in). The case has individual compartments for each size and type, making it easy to find the right fastener quickly and keep the set organized over time.
Is this set suitable for automotive use?
Yes. Class 10.9 alloy steel fasteners are commonly used in automotive and motorcycle assembly and repair. The M6, M8, and M10 sizes cover a wide range of engine, body, and frame fastening applications. Always verify torque specifications for your specific vehicle before installation.
Are these bolts compatible with standard metric tools?
Yes. The flange hex head design is compatible with standard metric hex sockets and wrenches. M6 bolts typically use a 10mm wrench, M8 uses 13mm, and M10 uses 17mm — though flange head dimensions may vary slightly from standard hex bolts.
Need a reliable metric fastener kit that covers the most common sizes? Add this 292-piece Class 10.9 assortment to your cart and keep your projects moving — no more stopping for a single missing bolt.
