621Pcs Nuts and Bolts Assortment Kit SAE Grade 8 - Heavy Duty Fastener

In this review of the 621Pcs Nuts and Bolts Assortment Kit the bottom line is simple: this kit is aimed at homeowners, mechanics and DIYers who need a heavy-duty, ready-to-use assortment of SAE fasteners for repairs and projects. The reviewer found the kit's single biggest strength to be the use of SAE Grade 8 alloy steel, which makes these hex bolts, nuts and washers appropriate for demanding applications where strength and fit matter. The included Y-wrench and drill bits also make it easy to get started without searching for tools.

Key Features

• Complete 621-piece set: Includes 180 hex bolts, 147 hex nuts, 147 washers and 147 lock washers so you have a broad range of sizes on hand for many jobs.
• Grade 8 alloy steel: High-strength construction means the fasteners resist deformation and are suitable for tougher automotive and machinery uses.
• Three common thread sizes: The set covers 1/4-20, 5/16-18 and 3/8-16 threads so most SAE fastening needs are covered for household and shop projects.
• Range of lengths: Bolt lengths span from short 1/2 in to longer 2 in pieces across the three thread sizes, allowing flexibility for furniture, motorcycle and machine repairs.
• Rugged labeled storage: A locking steel 21-hole tray with size labels keeps parts organized and protects them during transport and storage.
• Mounting tools included: The kit ships with a Y-wrench and three drill bit sizes to help with fit-up and initial mounting work.

Who It's For

The kit is well suited to home mechanics, hobbyists and small shops that regularly work on automotive, motorcycle, furniture and machinery repairs and want a single, durable assortment they can rely on. The predominance of Grade 8 alloy steel and the wide selection of lengths make it a practical choice for medium-duty structural and mechanical fastening.

Those who should look elsewhere include users who need only metric sizes or specialized coatings such as stainless or zinc-plated fasteners for corrosion resistance; the set focuses on SAE Grade 8 alloy parts rather than decorative or highly corrosion-resistant finishes.

Pros & Cons

Pros

• High-strength Grade 8 alloy steel fasteners suitable for demanding tasks.
• Large, organized 621-piece assortment provides good coverage of common SAE sizes.
• Durable steel storage tray with size labels keeps parts accessible and protected.
• Includes a Y-wrench and drill bits so you can start projects right away.

Cons

• Not a metric set and lacks stainless or plated options for high-corrosion environments.
• The tray is compact but may be heavy for portable use when fully loaded.

Specifications

Brand	FMhotu
Piece count	621 pcs
Thread sizes included	1/4-20, 5/16-18, 3/8-16
Bolt length range	1/2 in to 2 in depending on size
Material grade	SAE Grade 8 alloy steel
Packaging	Locking steel 21-hole tray, labeled (13-3/8 in x 7-3/4 in x 2 in)
Extras included	Y-wrench and 3 drill bit sizes

Our Verdict

The 621Pcs Nuts and Bolts Assortment Kit offers robust value for anyone needing a comprehensive SAE fastener selection built from Grade 8 alloy steel. It is especially useful to DIYers and small shops that want strength and organization in one package, and the included tools reduce the friction of getting started. It is not ideal for metric-only needs or projects requiring stainless or plated hardware, but for general mechanical and furniture work it is a solid, practical choice.

Frequently Asked Questions

Are metric sizes included?
No, this assortment contains SAE thread sizes 1/4-20, 5/16-18 and 3/8-16.

What is the material and grade of the fasteners?
The bolts, nuts and washers are made of SAE Grade 8 alloy steel for higher strength.

Does the kit include tools?
Yes, the package includes one Y-wrench and three drill bit sizes to assist with mounting.