Rectangular Head Bolt

Xiaoguo® offers a full range of standard and full-size Rectangular head bolt in stock, with the dimensional tolerance strictly controlled at ±0.1mm. Provide material certificates and salt spray reports, offer customs clearance services, and enable customers to enjoy a one-stop shopping experience.

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Product Description

How to choose the appropriate surface treatment?

Choosing the appropriate surface treatment for Rectangular head bolt is crucial in balancing the aspects of corrosion resistance, production cost, and environmental compliance. Bolts are metal products that need to withstand various working environments such as oil contamination, moisture, and chemical erosion. Selecting the right surface treatment is essential for maximizing the performance of the product and is something we need to consider.

（1）Environment

In an indoor dry environment, electro-galvanizing is the most cost-effective choice.

In outdoor humid or salt-spray environments, hot-dip galvanizing or Dacromet coating must be used.

In extremely corrosive environments (such as in chemical plants or at sea), duralumin or Teflon coatings are more reliable.

（2）Intensity

For high-strength Rectangular head bolt of grade 10.9 and above, due to the risk of hydrogen embrittlement, ordinary electro-galvanizing is strictly prohibited. Instead, processes such as dactron, phosphating, zinc-nickel alloy, or mechanical galvanizing, which do not cause hydrogen embrittlement, should be selected.

（3）Cost

Under the condition of meeting performance requirements, the costs of electro-galvanizing and blackening are the lowest.

The prices of phosphating and hot-dip galvanizing are moderate.

The costs of high-performance coatings such as Dacromet, zinc-nickel alloy and Teflon are higher and are suitable for scenarios with strict performance requirements.

（4）Special Requirements

In the electronics field, nickel plating may be necessary for electrical conductivity.

For situations where adhesion is a concern, Teflon can be chosen.

A perfect appearance and outstanding corrosion resistance are required. Electrostatic painting is a suitable option.

Rectangular Head Bolt

Comparison with the structures of other bolts

Feature	Rectangular head bolt	Hex head Bolt
Head shape	Square	Hexagon
Wrench contact surface	4 planes	6 planes
Force application area	Large(width of opposite sides)	Medium
Anti-slip performance	Excellent(less prone to slipping in oily environments)	Average
Anti-reverse mechanism	Can be combined with mechanical anti-reverse mechanism with square holes.	It needs to be fixed on the side of the head using a wrench.
Single-sided installation capability	Yes (compatible with round holes)	No
Torque transmission capacity	High (able to withstand large torque)	Medium
Head height	High (approximately 0.5 - 0.7 times the width across the opposite side)	Medium
Blind assembly adaptability	Excellent (The round head makes it easy to find by blind touch)	Medium

Rectangular Head Bolt

Mon	3/8	7/16	1/2	5/8	3/4	7/8	1	1-1/8	1-1/4	1-3/8	1-1/2
P	16\|24\|32	14\|20\|28	13\|20\|28	11\|18\|24	10\|16\|20	9\|1420	8\|1220	7\|12\|18	7\|12\|18	6\|12\|18	6\|12\|18
ds max	0.388	0.452	0.515	0.642	0.768	0.895	1.022	1.149	1.277	1.404	1.531
s max	0.562	0.625	0.75	0.938	1.125	1.312	1.5	1.688	1875	2.062	2.25
s min	0.544	0.603	0.725	0.906	1.088	1.269	1.45	1.631	1.812	1.994	2.175
e max	0.795	0.884	1.061	1.326	1.591	1.856	2.121	2.386	2.652	2.917	3.182
e min	0.747	0.828	0.995	1.244	1.494	1.742	1.991	2.239	2.489	2.738	2.986
k max	0.268	0.316	0.348	0.444	0.524	0.62	0.684	0.78	0.876	0.94	1.036
k min	0.232	0.278	0.308	0.4	0.476	0.568	0.628	0.72	0.812	0.872	0.964
r max	0.03	0.03	0.03	0.06	0.06	0.06	0.09	0.09	0.09	0.09	0.09
r min	0.01	0.01	0.01	0.02	0.02	0.02	0.03	0.03	0.03	0.03	0.03