The best assorted bolts and nuts kit depends on whether your projects use metric or SAE sizes, how many fasteners you need, and what material suits the job. The smseace kit is a compact metric choice for general repairs, while wugongshan offers more metric pieces in an organized case. Bonost covers several metric and SAE styles, Besitu is a 304 stainless-steel SAE option, and Kadrick provides a larger stainless-steel assortment.
| Kit | Best for | System and material |
|---|---|---|
| smseace 516-piece kit | Everyday metric repairs | Metric, carbon steel |
| wugongshan 1,080-piece kit | Metric machine screws and storage | Metric, metal |
| Bonost 3,010-piece kit | Broad workshop coverage | SAE and metric, carbon steel |
| Besitu 252-piece kit | Common SAE fastening tasks | SAE, 304 stainless steel |
| Kadrick 744-piece kit | SAE projects needing stainless hardware | SAE, 18-8 (304) stainless steel |
smseace 516-Piece Metric Assortment
This kit includes 516 pieces across 13 screw sizes, four nut sizes, and four flat-washer sizes in the M3, M4, M5, and M6 range. Its carbon-steel construction is described as corrosion- and oxidation-resistant, and the product information highlights clean, smooth threads intended to reduce slipping during installation.
Best for: Buyers handling routine metric repairs on machinery, furniture, motorcycles, or other equipment. Its mix of common metric sizes makes it a practical general-purpose option without the large piece count of a workshop-scale set.
Limitation: It is a metric assortment, so it will not replace SAE fasteners where an inch-based thread is required. The listed features specify flat washers, not lock washers.
wugongshan 1,080-Piece Metric Kit
The wugongshan assortment contains M3, M4, M5, and M6 cross-slotted round-head machine screws, nuts, and flat washers. Its 1,080 pieces are stored in separate compartments in a plastic case, which the product description says is designed to help keep sizes organized and accessible. The listed material is metal, with smooth edges and threads.
Best for: People who regularly use cross-slotted metric machine screws and want a sizable supply organized by size. It is better suited than a small kit to recurring repair or DIY work that uses these specific fastener styles.
Limitation: The assortment is focused on round-head, cross-slotted screws in M3–M6 sizes. Check the head style and dimensions needed for your project before choosing it.
Bonost 3,010-Piece Multi-Style Kit
This large assortment is split across four trays and includes SAE Phillips-head bolts, metric Phillips-head bolts, and metric hex bolts. The metric ranges include M3 through M8, with matching nuts and washers; the hex-bolt assortment also includes locking washers. Carbon steel and zinc coatings are listed, along with a stackable case and fastener guide.
Best for: Workshops that use both SAE and metric hardware and need several head styles in one kit. Its broad selection is the strongest reason to choose it over a smaller, single-system assortment.
Limitation: A high piece count does not guarantee that a specific length or thread matches your repair. Confirm the individual size in the included guide before starting work.
Besitu 252-Piece Stainless SAE Kit
Besitu’s 252-piece kit covers 10 SAE sizes using 1/4-20, 5/16-18, and 3/8-16 fasteners. It includes hex bolts, nuts, and washers, with fully threaded 304 stainless-steel bolts. The product description also notes storage bins and a size chart on the inside and outside of the case.
Best for: Buyers who need common inch-based hex bolts and prefer stainless-steel hardware for general use, including some outdoor or wet settings. Choose this over a metric kit when the existing threads are SAE.
Limitation: The size range is limited to the listed thread diameters and lengths. Stainless-steel hardware is not automatically the right choice for every load-bearing application; match fastener specifications to the job.
Kadrick 744-Piece Stainless SAE Kit
Kadrick’s kit contains 744 pieces, including 186 bolts, hex nuts, and flat and lock washers across 15 specifications. Its fasteners are identified as 18-8 (304) stainless steel. The portable box has a handle, more than 15 compartments, and labeled sections for identifying hardware.
Best for: SAE users who want more pieces and washer options than the Besitu kit lists. The labeled compartments and carrying handle are useful when hardware needs to be stored or moved between work areas.
Limitation: This is an SAE assortment, not a metric kit. Review the listed specifications to ensure the bolt lengths and thread sizes cover your repair.
Buying Guide: How To Choose An Assorted Fastener Kit
Should you buy metric or SAE bolts and nuts?
Match the kit to the threads already used by the equipment. Metric fasteners are marked in millimeters, such as M4 or M6; SAE sizes use inch-based designations, such as 1/4-20. These systems are not interchangeable. Confirm diameter, thread pitch, and length rather than relying on appearance alone.
How many pieces and sizes do you need?
A smaller kit can be easier to store and may suit occasional household fixes. A larger set may offer more size choices for a shared workshop, but check the contents list: total piece count alone does not show how many sizes, lengths, or fastener styles are included.
Which material is right for the job?
Carbon steel kits can be useful for general indoor repairs, while stainless-steel options are described as corrosion-resistant and may suit some outdoor or damp conditions. Coatings and material do not replace checking the fastener’s required strength, environment, and application. Follow the equipment maker’s specifications when available.
Do washers and storage matter?
Check whether the kit includes flat washers, lock washers, or both; they serve different purposes. Compartmentalized cases and size charts can make it easier to identify a fastener and keep parts separated. Before relying on a kit, verify that its labeled compartments match the contents.
Frequently Asked Questions
Can metric and SAE nuts and bolts be used together?
No. Their thread dimensions differ, and forcing mismatched fasteners can damage threads. Identify the required system and size first.
What do M3, M4, and M6 mean?
These labels indicate metric thread-size families. Check the full fastener specification, including length and pitch where relevant, before selecting a replacement.
Are stainless-steel bolts suitable for every repair?
No. Stainless steel can resist corrosion, but the correct material and strength depend on the application. Use the specified fastener for safety-critical or load-bearing repairs.
Why choose a kit with lock washers?
Lock washers are included in some assortments as an additional washer type. Check the repair’s requirements and use the washer style specified for the joint.
How should I store assorted bolts and nuts?
Keep each size in a labeled compartment, close the case securely, and replace mixed or unreadable labels. This helps prevent choosing the wrong diameter or thread during a repair.