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ASME B18.3 (T8):2012 Countersunk Head Hex Socket Screw
ASME B18.3 (T8):2012 Countersunk Head Hex Socket Screw combines a hex socket drive with a countersunk head, making it suitable for fastening points that require reliable clamping, removable maintenance, and standardized assembly. The ASME standard framework suits projects requiring U.S.-standard compatibility and engineering applicability, supporting smooth alignment between engineering drawings, purchasing lists, and quality inspection.
From an assembly perspective, the internal hex socket provides deeper tool engagement, enabling higher assembly torque in compact spaces while reducing external head interference. At the same time, the tapered head seats into a prepared countersink, allowing the screw to sit flush or nearly flush with the surface, so the screw can provide stable fastening performance across different sheet thicknesses, appearance requirements, and space limitations.
It works well on flat surfaces, rails, covers, module housings, and areas where snagging or interference should be avoided. For exposed equipment positions, head forming quality, recess integrity, edge chamfering, and coating uniformity can be emphasized so fastening performance aligns with the finished product appearance.
Dimensions unit: inch
|
Nominal diameter d |
0# |
1# |
2# |
3# |
4# |
5# |
6# |
8# |
10# |
12# |
1/4 |
5/16 |
|
|
d |
Nominal diameter |
0.06 |
0.073 |
0.086 |
0.099 |
0.112 |
0.125 |
0.138 |
0.164 |
0.19 |
0.2158 |
0.25 |
0.3125 |
|
PP |
Coarse teeth/UNC |
- |
64 |
56 |
48 |
40 |
40 |
32 |
32 |
24 |
24 |
20 |
18 |
|
Fine Teeth/UNF |
80 |
72 |
64 |
56 |
48 |
44 |
40 |
36 |
32 |
28 |
28 |
24 |
|
|
Extra-Fine Thread/UNEF |
- |
- |
- |
- |
- |
- |
- |
- |
- |
32 |
32 |
32 |
|
|
ds |
Max. |
0.06 |
0.073 |
0.086 |
0.099 |
0.112 |
0.125 |
0.138 |
0.164 |
0.19 |
0.2158 |
0.25 |
0.3125 |
|
Min. |
0.0568 |
0.0695 |
0.0822 |
0.0949 |
0.1075 |
0.1202 |
0.1329 |
0.1585 |
0.184 |
0.2102 |
0.2435 |
0.3053 |
|
|
dk |
Max. |
0.138 |
0.168 |
0.197 |
0.226 |
0.255 |
0.281 |
0.307 |
0.359 |
0.411 |
0.45 |
0.531 |
0.656 |
|
Min. |
0.117 |
0.143 |
0.168 |
0.193 |
0.218 |
0.24 |
0.263 |
0.311 |
0.359 |
0.41 |
0.48 |
0.6 |
|
|
k |
Reference |
0.044 |
0.054 |
0.064 |
0.073 |
0.083 |
0.09 |
0.097 |
0.112 |
0.127 |
0.135 |
0.161 |
0.198 |
|
s |
Nominal |
- |
- |
- |
1/16 |
1/16 |
5/64 |
5/64 |
3/32 |
1/8 |
1/8 |
5/32 |
3/16 |
|
Nominal |
0.035 |
0.05 |
0.05 |
0.062 |
0.062 |
0.078 |
0.078 |
0.094 |
0.125 |
0.125 |
0.156 |
0.188 |
|
|
t |
Min. |
0.025 |
0.031 |
0.038 |
0.044 |
0.055 |
0.061 |
0.066 |
0.076 |
0.087 |
0.094 |
0.111 |
0.135 |
|
b |
Min. |
0.5 |
0.62 |
0.62 |
0.62 |
0.75 |
0.75 |
0.75 |
0.88 |
0.88 |
0.88 |
1 |
1.12 |
|
α |
±2° |
82° |
82° |
82° |
82° |
82° |
82° |
82° |
82° |
82° |
82° |
82° |
82° |
|
Nominal diameter d |
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 |
|
|
d |
Nominal diameter |
0.375 |
0.4375 |
0.5 |
0.625 |
0.75 |
0.875 |
1 |
1.125 |
1.25 |
1.375 |
1.5 |
|
PP |
Coarse teeth/UNC |
16 |
14 |
13 |
11 |
10 |
9 |
8 |
7 |
7 |
6 |
6 |
|
Fine Teeth/UNF |
24 |
20 |
20 |
18 |
16 |
14 |
12 |
12 |
12 |
12 |
12 |
|
|
Extra-Fine Thread/UNEF |
32 |
28 |
28 |
24 |
20 |
20 |
20 |
18 |
18 |
18 |
18 |
|
|
ds |
Max. |
0.375 |
0.4375 |
0.5 |
0.625 |
0.75 |
0.875 |
1 |
1.125 |
1.25 |
1.375 |
1.5 |
|
Min. |
0.3678 |
0.4294 |
0.4919 |
0.6163 |
0.7406 |
0.8647 |
0.9886 |
1.1086 |
1.2336 |
1.3568 |
1.4818 |
|
|
dk |
Max. |
0.781 |
0.844 |
0.938 |
1.188 |
1.438 |
1.688 |
1.938 |
2.188 |
2.438 |
2.688 |
2.938 |
|
Min. |
0.72 |
0.781 |
0.872 |
1.112 |
1.355 |
1.604 |
1.841 |
2.079 |
2.316 |
2.553 |
2.791 |
|
|
k |
Reference |
0.234 |
0.234 |
0.251 |
0.324 |
0.396 |
0.468 |
0.54 |
0.611 |
0.683 |
0.755 |
0.827 |
|
s |
Nominal |
7/32 |
1/4 |
5/16 |
3/8 |
1/2 |
9/16 |
5/8 |
3/4 |
7/8 |
7/8 |
1 |
|
Nominal |
0.219 |
0.25 |
0.312 |
0.375 |
0.5 |
0.562 |
0.625 |
0.75 |
0.875 |
0.875 |
1 |
|
|
t |
Min. |
0.159 |
0.159 |
0.172 |
0.22 |
0.22 |
0.248 |
0.297 |
0.325 |
0.358 |
0.402 |
0.435 |
|
b |
Min. |
1.25 |
1.38 |
1.5 |
1.75 |
2 |
2.25 |
2.5 |
2.81 |
3.12 |
3.44 |
3.75 |
|
α |
±2° |
82° |
82° |
82° |
82° |
82° |
82° |
82° |
82° |
82° |
82° |
82° |
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FAQ
Frequently Asked Questions
-
1. How soon can I expect a reply after sending an inquiry?
A: We take every inquiry seriously. On working days, we will respond within 12 hours after receiving your inquiry.
-
2. What products do you mainly offer?
A: We focus on the production of fasteners made of carbon steel, stainless steel, and low-alloy steel. We are a direct manufacturer with independent production capacity. ASME B18.3 (T8):2012 Countersunk Head Hex Socket Screw Factory. We own several fastener manufacturing facilities and have an international sales department, providing full-process services from production to export.
-
3. Do you support customized production?
A: Customized production is our core business. We can develop and manufacture products based on the drawings or samples you provide.
-
4. Do you produce standard parts?
A: Yes. In addition to custom products, we also produce general construction machinery parts (GET parts) for equipment such as excavators, including bucket teeth, tooth holders, corner blades, pins, clips, bolts and nuts. ASME B18.3 (T8):2012 Countersunk Head Hex Socket Screw Wholesale.
-
5. What is your production capacity?
A: We have 12 energy-efficient and environmentally friendly modern production lines (including one fully automatic shell molding line and four heat treatment lines), with an annual production capacity exceeding 20,000 tons, enabling us to steadily meet various order requirements.
-
6. What are your payment terms?
A: Trade terms (such as FOB, CIF, etc.) are confirmed when quoting. For batch production, we typically require a 30% deposit, with the balance paid against the copy of the bill of lading. T/T is the main payment method accepted, and L/C can also be negotiated.
-
7. How is the shipment arranged?
A: We are only 35 km away from Shanghai Port and Ningbo Port, so sea freight is the main mode of transportation, which is convenient and efficient. For urgent deliveries, we can also arrange air freight via Ningbo or Shanghai airports.
About Us
BETTER FASTENER INDUSTRY CO., LTD.
Better Fastener is a professional fastener enterprise specializing in the manufacturing of steel washers, stainless steel washers, spring washers and sealingwashers. Founded in 2001 as a washer factory, the company expanded into a comprehensive enterprise integrating washers, nuts, bolts, spring nuts and other fastener products in 2010. ASME B18.3 (T8):2012 Countersunk Head Hex Socket Screw Suppliers in China.
The company positions itself as a provider of comprehensive one-stop services for customers, relying on technological R&D, industrial investment and trade distribution.
With an experienced professional team and a sound sales network, Better Fastener has achieved excellent sales performance in both domestic and foreign markets,and has grown into one of the competitive manufacturers and suppliers in China's industrial fastener industry.
Better Fastener is committed to becoming a trusted fastener supplier for customers with reliable product quality, reasonable prices and on-time deliveryCertification
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phone：+86-0571 85382212
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E-Mail：export@betterfastener.com
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Whatsapp：+86 15372362589
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