Best Steel Square Head Bolts in 2026
Daisy
Last Updated: Jul 17, 2026
Daisy
Last Updated: Jul 17, 2026
* PickSmartly editors independently research, review, and endorse the top products through comprehensive data analysis. We may earn a commission for qualifying purchases made through our product links.
| SELLER | SELLER SCORE | AMAZON FULFILLED | PRIME | FREE SHIPPING |
|---|---|---|---|---|
| Eastlo | 9.92 | ✅ | ✅ | ✅ |
Contents: 25 PCS 1/4-20 x 1-1/2 inch carriage bolt with round domed head and suqare neck
Screw Length: 1-1/2 inch or 38mm (measured from under the round head, including the neck height)
Big round domed head designed to eliminate the need for a washer; Square neck underneath the head helps self locking
Diameter of the head: 14.3-15mm; Height of the round head: 3.18-3.68mm; Height of the Neck:3.18-3.96mm
Made of 304 stainless steel 18-8 (no coating outside) which is superior to regular steel and any zinc plated fasteners, provides good strength and corrosion resistance in bad environments
| SELLER | SELLER SCORE | AMAZON FULFILLED | PRIME | FREE SHIPPING |
|---|---|---|---|---|
| MewuDecor Online | 9.86 | ✅ | ✅ | ✅ |
The carriage bolts are 100% stainless steel 18-8 (304) which offers a high level of chemical and corrosion resistance.
System of Measurement: Inch; Finish: Bright Finish.
Thread Diameter: 1/4 Inch; Thread Count: 20; Head Diameter: 0.594 Inch; Head Height: 0.145 Inch; Screw Length: 1-1/2 Inch.
Package Included: 25 x Carriage Bolts.
These bolts can be used in high-stress applications, such as valves, pumps, motors, and automotive suspension systems.
| SELLER | SELLER SCORE | AMAZON FULFILLED | PRIME | FREE SHIPPING |
|---|---|---|---|---|
| Discount Distributors LLC | 6.05 | ✅ | ✅ | ✅ |
Thread Diameter 0.250"
Head Diameter 0.594"
Head Height 0.145"
Square Neck Height 0.156" / Square Neck Width 0.26"
18-8 Stainless Steel provides strength and offers good corrosion resistance in many environments.
| SELLER | SELLER SCORE | AMAZON FULFILLED | PRIME | FREE SHIPPING |
|---|---|---|---|---|
| Aoesin | 9.95 | ✅ | ✅ | ✅ |
Standard: ASME/ANSI B18.5
Thread Size: 3/8 inch; Thread Pitch: 16 threads per inch (TPI)
Head Diameter: 0.782 inch to 0.844 inch; Head Height: 0.188 inch to 0.288 inch
Screw Length (include the square neck): 4 inch
Material: 304 Stainless Steel 18-8 that you will probably see in your pans and cookery tools. It's used for a wide variety of home and commercial applications. Because of its slightly higher strength and wear resistance than type 316, it's also used for nuts, bolts, screws and other fasteners.
| SELLER | SELLER SCORE | AMAZON FULFILLED | PRIME | FREE SHIPPING |
|---|---|---|---|---|
| FASTENER DEPOT, LLC | 9.77 | ❌ | ❌ | ❌ |
Thread Diameter 0.3125"
Head Diameter 0.719"
Head Height 0.176"
Square Neck Height 0.187" / Square Neck Width 0.32"
18-8 Stainless Steel provides strength and offers good corrosion resistance in many environments.
| SELLER | SELLER SCORE | AMAZON FULFILLED | PRIME | FREE SHIPPING |
|---|---|---|---|---|
| Amazon.com | 9.68 | ✅ | ✅ | ✅ |
Carriage Bolts are designed to fasten a wooden face to either wood or metal
Flat head provides a semi-flush finish to applications
The heads is designed to eliminate the need for a washer
Square underside of the head is self locking to eliminate the need for a driving tool
Galvanized finish is perfect for rust prevention
| SELLER | SELLER SCORE | AMAZON FULFILLED | PRIME | FREE SHIPPING |
|---|---|---|---|---|
| Gatzies | 9.78 | ❌ | ❌ | ❌ |
Carriage Bolts are designed to fasten a wooden face to either wood or metal
Flat head provides a semi-flush finish to applications
The heads is designed to eliminate the need for a washer
Square underside of the head is self locking to eliminate the need for a driving tool
Galvanized finish is perfect for rust prevention
| SELLER | SELLER SCORE | AMAZON FULFILLED | PRIME | FREE SHIPPING |
|---|---|---|---|---|
| Amazon.com | 9.68 | ✅ | ✅ | ✅ |
Carriage Bolts are designed to fasten a wooden face to either wood or metal
Flat head provides a semi-flush finish to applications
The heads is designed to eliminate the need for a washer
Square underside of the head is self locking to eliminate the need for a driving tool
Galvanized finish is perfect for rust prevention
| SELLER | SELLER SCORE | AMAZON FULFILLED | PRIME | FREE SHIPPING |
|---|---|---|---|---|
| Amazon.com | 9.68 | ✅ | ✅ | ✅ |
Carriage Bolts are designed to fasten a wooden face to either wood or metal
Flat head provides a semi-flush finish to applications
The heads is designed to eliminate the need for a washer
Square underside of the head is self locking to eliminate the need for a driving tool
Galvanized finish is perfect for rust prevention
| SELLER | SELLER SCORE | AMAZON FULFILLED | PRIME | FREE SHIPPING |
|---|---|---|---|---|
| Amazon.com | 9.68 | ✅ | ✅ | ✅ |
Carriage Bolts are designed to fasten a wooden face to either wood or metal
Flat head provides a semi-flush finish to applications
The heads is designed to eliminate the need for a washer
Square underside of the head is self locking to eliminate the need for a driving tool
Galvanized finish is perfect for rust prevention
| SELLER | SELLER SCORE | AMAZON FULFILLED | PRIME | FREE SHIPPING |
|---|---|---|---|---|
| Amazon.com | 9.68 | ✅ | ✅ | ✅ |
Carriage Bolts are designed to fasten a wooden face to either wood or metal
Flat head provides a semi-flush finish to applications
The heads is designed to eliminate the need for a washer
Square underside of the head is self locking to eliminate the need for a driving tool
Galvanized finish is perfect for rust prevention
| SELLER | SELLER SCORE | AMAZON FULFILLED | PRIME | FREE SHIPPING |
|---|---|---|---|---|
| Amazon.com | 9.68 | ✅ | ✅ | ✅ |
Carriage Bolts are designed to fasten a wooden face to either wood or metal
Flat head provides a semi-flush finish to applications
The heads is designed to eliminate the need for a washer
Square underside of the head is self locking to eliminate the need for a driving tool
Galvanized finish is perfect for rust prevention
| SELLER | SELLER SCORE | AMAZON FULFILLED | PRIME | FREE SHIPPING |
|---|---|---|---|---|
| Amazon.com | 9.68 | ✅ | ✅ | ✅ |
Carriage Bolts are designed to fasten a wooden face to either wood or metal
Flat head provides a semi-flush finish to applications
The heads is designed to eliminate the need for a washer
Square underside of the head is self locking to eliminate the need for a driving tool
Galvanized finish is perfect for rust prevention
| SELLER | SELLER SCORE | AMAZON FULFILLED | PRIME | FREE SHIPPING |
|---|---|---|---|---|
| Amazon.com | 9.68 | ✅ | ✅ | ✅ |
Carriage Bolts are designed to fasten a wooden face to either wood or metal
Flat head provides a semi-flush finish to applications
The heads is designed to eliminate the need for a washer
Square underside of the head is self locking to eliminate the need for a driving tool
Galvanized finish is perfect for rust prevention
| SELLER | SELLER SCORE | AMAZON FULFILLED | PRIME | FREE SHIPPING |
|---|---|---|---|---|
| Amazon.com | 9.68 | ✅ | ✅ | ✅ |
Carriage Bolts are designed to fasten a wooden face to either wood or metal
Flat head provides a semi-flush finish to applications
The heads is designed to eliminate the need for a washer
Square underside of the head is self locking to eliminate the need for a driving tool
Galvanized finish is perfect for rust prevention
| SELLER | SELLER SCORE | AMAZON FULFILLED | PRIME | FREE SHIPPING |
|---|---|---|---|---|
| Amazon.com | 9.68 | ✅ | ✅ | ✅ |
Carriage Bolts are designed to fasten a wooden face to either wood or metal
Flat head provides a semi-flush finish to applications
The heads is designed to eliminate the need for a washer
Square underside of the head is self locking to eliminate the need for a driving tool
Galvanized finish is perfect for rust prevention
Here is the list of top-rated brands that were evaluated by PM.
| Brand | Count |
|---|---|
| Hillman | 11 |
| Fastenere | 2 |
| Aoesin | 1 |
| Eastlo | 1 |
| Mewudecor | 1 |
We've carried out a comprehensive analysis of 545 reviews on square head bolts, using our selection criteria to identify the best options in the fasteners. Our findings reveal that most customers typically select square head bolts priced around $35.73, with top brands including hard-to-find fastener and small parts and uxcell
Our team of expert editors reviewed these high-quality items and handpicked the top 16 square head bolts for your consideration. We've also done extensive research on numerous sellers, identifying the best ones in the fasteners category. These include and amazon.com and amadeo city .
We are dedicated to assisting our users in finding the right bolts Products based on their needs, saving them considerable time when choosing which square head bolts to buy. We take pride in the number of satisfied users we've helped through our thorough and insightful reviews.
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