The best 3/4-inch square head bolt depends on the thread, length, and quantity your project requires. The four 1/2-13 options below list a 3/4-inch-square head; choose among them by bolt length and pack size. A separate 3/4-10 option has a larger 1-1/8-inch-square head, so it is for buyers who need a 3/4-inch thread diameter—not a 3/4-inch head.
| Product | Best For | Key Difference |
|---|---|---|
| Lexar Industrial 1/2-13 x 1-1/2 | Shorter bolts in a bulk pack | 60 pieces; unplated |
| Lexar Industrial 1/2-13 x 3 | Longer bolts in a bulk pack | 35 pieces; unplated |
| uxcell 1/2-13 x 2 | Small projects needing five bolts | Black oxide finish |
| uxcell 1/2-13 x 3 | Longer bolts in a two-piece pack | Black oxide finish |
| Lexar Industrial 3/4-10 x 4 | Projects needing a 3/4-inch thread | Head measures 1-1/8 inches square |
Lexar Industrial 1/2-13 x 1-1/2-Inch
This pack contains 60 unplated square head bolts with a 1/2-13 thread and a listed length of 1-1/2 inches. The product name specifies a 3/4-inch-square head. The listing gives an ASTM A310 specification; check the product information carefully if a particular standard is required for your application.
Best for: Buyers who need a supply of shorter 1/2-13 bolts for repeated jobs. Its larger pack is the main distinction from the smaller uxcell options. Limitation: The bolts are unplated, and the listing does not describe a protective finish.
Lexar Industrial 1/2-13 x 3-Inch
This bulk pack has 35 unplated bolts with 1/2-13 threads and a 3-inch length. The product name identifies a 3/4-inch-square head. Its longer shank makes it a better match than the 1-1/2-inch Lexar option when the required bolt length is three inches.
Best for: Projects that call for longer 1/2-13 square head bolts and multiple pieces. The listing gives ASTM A314 as its specification. Limitation: The unplated finish may not suit an application that requires a specified coating; verify the required material and standard before ordering.
uxcell 1/2-13 x 2-Inch Black Oxide
This five-piece set uses carbon steel with a black oxide surface. Each bolt has a 1/2-13 thread, a listed length of 2 inches, a 38 mm thread length, and a head measuring 19 by 8.5 mm—approximately 3/4 by 0.33 inches. The listing describes a partially threaded design.
Best for: Smaller jobs needing five medium-length bolts with a black oxide finish. Limitation: The pack contains only five pieces, and the finish should be checked against the conditions of the intended use rather than assumed suitable for every environment.
uxcell 1/2-13 x 3-Inch Black Oxide
This two-piece carbon-steel set has 1/2-13 threads and a listed 3-inch length. Its black oxide finish, 50 mm thread length, and 19 by 8.5 mm head dimensions are specified in the listing. The head is approximately 3/4 inch wide, making this a closer match to the keyword than bolts with larger heads.
Best for: Buyers who need a pair of longer 1/2-13 bolts and prefer the listed black oxide surface. Limitation: Choose another option if you need a larger pack or a documented material specification not provided in the product details.
Lexar Industrial 3/4-10 x 4-Inch
This option has a 3/4-10 thread diameter, a 4-inch length, and a square head listed as 1-1/8 inches across. It is included for buyers using “3/4 square head bolt” to mean a bolt with a 3/4-inch diameter. It is not a match if the required head width is 3/4 inch.
Best for: Applications that specifically call for a 3/4-10 thread and the larger square head. Limitation: The head is larger than 3/4 inch, and the listing provides limited detail beyond diameter, length, and head type. Confirm the full specification before purchase.
Buying Guide
Does 3/4 inch refer to the head or the thread?
Check the measurement convention before choosing a bolt. A 3/4-inch-square head is not the same as a 3/4-inch thread diameter. The 1/2-13 products above are listed with heads around 3/4 inch wide. The 3/4-10 Lexar bolt has a larger, 1-1/8-inch-square head.
How do thread and length affect the choice?
Match the thread diameter and pitch to the receiving hole or nut. In these listings, 1/2-13 means a 1/2-inch thread diameter with 13 threads per inch. Compare the specified bolt length with the thickness of the materials being joined and the required thread engagement. Do not assume that equal thread sizes make different lengths interchangeable.
Which finish and pack size should you choose?
Choose unplated Lexar bolts if that finish fits the job and you need a larger quantity. The uxcell options are black oxide carbon steel and come in two- or five-piece packs. Confirm finish requirements for the installation environment; the product descriptions alone do not establish suitability for every exposure or application.
What specifications should you verify?
Check the product listing for head width, bolt length, thread length, material, finish, and any required standard. The two Lexar 1/2-13 listings provide different ASTM references, so verify the specified standard rather than treating them as interchangeable. Confirm dimensions against the project drawing or existing hardware before ordering.
Frequently Asked Questions
What does 1/2-13 mean on a square head bolt?
It indicates a 1/2-inch thread diameter and 13 threads per inch. It does not describe the head width or bolt length.
Which listed bolts have a 3/4-inch-square head?
The product names for both Lexar 1/2-13 bolts specify a 3/4-inch-square head. The uxcell listings give head dimensions of 19 mm by 8.5 mm, approximately 3/4 by 0.33 inches.
Is the 3/4-10 Lexar bolt a 3/4-inch head bolt?
No. Its 3/4-10 designation refers to the thread diameter and pitch. The listed head is 1-1/8 inches square.
Are black oxide and unplated finishes interchangeable?
Not necessarily. They are different listed surface conditions. Select the finish that matches the project requirements, and verify suitability for the intended environment.