Best Hex Washer Head Bolt Options for Repairs and Projects
If you need a hex washer head bolt, first check whether you want a bolt with a washer-like flange built into its head or a standard hex-head bolt used with a separate washer. The products below are assorted hex-head fastener kits, not products described as integrated-flange washer head bolts. The MroMax set is best for common 1/4-inch hardware, while the Hicarer set suits larger 1/2-inch applications. Metric projects may be better served by the stainless M4–M6 assortment or the M3 and M6 socket screw kits.
| Product | Best For | Key Detail |
|---|---|---|
| Stainless M4–M6 assortment | General metric repairs | 304 stainless steel; flat and spring washers |
| M6 socket screw kit | M6 metric projects | Eight lengths; 12.9-grade alloy steel |
| MroMax 1/4-20 set | Inch-size assemblies | Fully threaded, 2-inch stainless bolts |
| Hicarer 1/2-13 set | Large fasteners | Six-inch bolts, nylon lock nuts, large washers |
| M3 socket screw kit | Small metric projects | Eight lengths; 750-piece assortment |
304 Stainless M4–M6 Bolt Assortment
This 496-piece assortment includes metric M4, M5, and M6 hex-head bolts, nuts, flat washers, and spring lock washers. Its listed material is 304 stainless steel, which the product description identifies as resistant to rust and corrosion. Flat washers increase the contact area, while spring washers are intended to provide tension in a joint assembly.
Best for: Buyers handling varied metric repairs who want matching nuts and two washer types in one kit. It is the closest match here to a standard hex bolt paired with separate washers. Limitation: The listing does not specify bolt lengths in the provided details, so confirm the assortment’s size breakdown before purchase. It is not identified as an integrated washer-head bolt.
Fgruh M6 Socket Screw Kit
This 185-piece kit contains M6-1.0 socket cap head bolts in eight lengths, from 8 mm to 35 mm, along with nuts and washers. The listed material is 12.9-grade alloy steel with a black zinc finish. The product describes it for DIY repairs, 3D printing, electronics, RC models, and CNC machinery.
Best for: Buyers who need several M6 lengths for metric assemblies and prefer a hex socket drive. The selection of eight lengths makes it more adaptable than a single-size bolt set. Limitation: These are socket cap head screws, not conventional external-hex bolts or integrated washer-head bolts; check the drive type and dimensions required by the project.
MroMax 1/4-20 Stainless Bolt Sets
This product supplies 20 sets of fully threaded 1/4-20 hex-head bolts, each 2 inches long, with nuts, flat washers, and spring lock washers. The bolts are listed as 304 stainless steel with a bright finish. The 20 TPI thread specification helps distinguish this inch-size fastener from metric alternatives.
Best for: Projects that call for a 1/4-inch diameter, 20-thread-per-inch bolt and a complete nut-and-washer combination. Choose it over the metric kits when the required thread is 1/4-20. Limitation: The bolt length is specified as 2 inches, so it is not a varied-length assortment.
Hicarer 1/2-13 Long Bolt Kit
The Hicarer kit includes 10 sets of 1/2-13 x 6-inch hex-head bolts, nylon lock nuts, and large-size washers. The bolts are described as Grade 5 alloy steel with color galvanizing. The listing presents the finish as corrosion- and rust-resistant and identifies the set for indoor and outdoor use.
Best for: Buyers whose project requires a long, large-diameter inch bolt and a locking nut. Its 6-inch length and included large washers set it apart from the shorter, smaller fasteners here. Limitation: Confirm the unusually substantial 1/2-inch diameter and 6-inch length fit the assembly; this is not a general-purpose small-hardware assortment.
Fgruh M3 Socket Screw Assortment
This 750-piece kit contains M3-0.5 hex socket cap head bolts in eight lengths, from 6 mm to 30 mm, plus nuts and washers. The product lists 12.9-grade alloy steel and a black zinc finish. Suggested uses include 3D printing, electronics, RC models, DIY repairs, and CNC machinery.
Best for: Small metric assemblies that need M3 hardware in multiple lengths. It offers more pieces and smaller fasteners than the M6 kit. Limitation: M3 bolts are substantially smaller than the inch-size options and are socket-drive cap screws, so they are unsuitable when a project specifies a larger external hex head.
Buying Guide: How to Choose a Hex Washer Head Bolt
Do you need an integrated washer head?
A hex washer head bolt has a hexagonal head with a broad bearing surface, often formed as a flange. A standard hex bolt may instead require a separate flat washer. None of the products above is explicitly described as having an integrated washer head. If that feature is required, verify the head style in the listing or product drawing rather than assuming a separate washer makes the bolt equivalent.
Which thread and length should you match?
Match the fastener to the receiving hole or nut. The listed options include metric M3, M6, and M4–M6 assortments, plus inch threads 1/4-20 and 1/2-13. Metric and inch threads are not interchangeable. Check diameter, pitch or threads per inch, and the length measured below the head before ordering.
Should you choose stainless steel or alloy steel?
The 304 stainless options are specified as stainless steel, including the MroMax bolts and the M4–M6 kit. The socket screw assortments list 12.9-grade alloy steel, while Hicarer lists Grade 5 alloy steel with color galvanizing. Select based on the material and finish required by the application; the provided product details do not establish suitability for every environment or load.
Frequently Asked Questions
Is a hex washer head bolt the same as a hex bolt with a washer?
No. A washer-head bolt has a washer-like flange integrated into its head. A standard hex bolt uses a separate washer when needed.
Can I use metric bolts in an inch-threaded hole?
No. Metric and inch-threaded fasteners have different thread dimensions. Match the bolt to the specified thread standard.
What does 1/4-20 mean?
It identifies a 1/4-inch nominal thread diameter and 20 threads per inch, as specified for the MroMax bolts.
Which option includes separate washers?
The M4–M6 assortment and the MroMax 1/4-20 sets list flat and spring lock washers. The Hicarer set includes large-size washers.
Are socket cap screws external hex bolts?
No. Socket cap screws use a hexagonal recess for a key or driver, while external hex bolts have a hexagonal head turned from the outside.