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Stainless Steel Tamper-Resistant One-Way Round Head Screws
Made from 18-8 stainless steel, these screws have good chemical resistance and may be mildly magnetic. They’re passivated for added protection against oxidation and corrosion. The S-shaped drive can be installed with a standard slotted driver, but requires a special tool for removal (sold separately). For removal tools, see one-way bits and drivers. Length is measured from under the head.
For technical drawings and 3-D models, click on a part number.
| Lg. | Threading | Head Dia. | Head Ht. | Tensile Strength, psi  | Specifications Met | Pkg. Qty. | Pkg. | |
18-8 Stainless Steel | ||||||||
|---|---|---|---|---|---|---|---|---|
4-40 | ||||||||
| 3/16" | Fully Threaded | 0.211" | 0.086" | 80,000 | __ | 100 | 000000000 | 000000 |
| 1/4" | Fully Threaded | 0.211" | 0.086" | 80,000 | __ | 100 | 000000000 | 00000 |
| 3/8" | Fully Threaded | 0.211" | 0.086" | 80,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
| 1/2" | Fully Threaded | 0.211" | 0.086" | 80,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
| 3/4" | Fully Threaded | 0.211" | 0.086" | 80,000 | __ | 100 | 000000000 | 00000 |
6-32 | ||||||||
| 3/16" | Fully Threaded | 0.260" | 0.103" | 80,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
| 1/4" | Fully Threaded | 0.260" | 0.103" | 80,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
| 3/8" | Fully Threaded | 0.260" | 0.103" | 80,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
| 1/2" | Fully Threaded | 0.260" | 0.103" | 80,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
| 3/4" | Fully Threaded | 0.260" | 0.103" | 80,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
| 1" | Fully Threaded | 0.260" | 0.103" | 80,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
| 1 1/2" | Fully Threaded | 0.260" | 0.103" | 80,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
8-32 | ||||||||
| 1/4" | Fully Threaded | 0.309" | 0.120" | 80,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
| 3/8" | Fully Threaded | 0.309" | 0.120" | 80,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
| 1/2" | Fully Threaded | 0.309" | 0.120" | 80,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
| 3/4" | Fully Threaded | 0.309" | 0.120" | 80,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
| 1" | Fully Threaded | 0.309" | 0.120" | 80,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
| 1 1/2" | Fully Threaded | 0.309" | 0.120" | 80,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
10-24 | ||||||||
| 1/2" | Fully Threaded | 0.359" | 0.137" | 80,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
| 3/4" | Fully Threaded | 0.359" | 0.137" | 80,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
| 1" | Fully Threaded | 0.359" | 0.137" | 80,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
| 1 1/4" | Fully Threaded | 0.359" | 0.137" | 80,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
| 1 1/2" | Fully Threaded | 0.359" | 0.137" | 80,000 | ASME B18.6.3 | 25 | 000000000 | 00000 |
10-32 | ||||||||
| 1/4" | Fully Threaded | 0.359" | 0.137" | 80,000 | __ | 50 | 000000000 | 00000 |
| 3/8" | Fully Threaded | 0.359" | 0.137" | 80,000 | __ | 50 | 000000000 | 00000 |
| 1/2" | Fully Threaded | 0.359" | 0.137" | 80,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
| 5/8" | Fully Threaded | 0.359" | 0.137" | 80,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
| 3/4" | Fully Threaded | 0.359" | 0.137" | 80,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
| 1" | Fully Threaded | 0.359" | 0.137" | 80,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
| 1 1/4" | Fully Threaded | 0.359" | 0.137" | 80,000 | ASME B18.6.3 | 25 | 000000000 | 00000 |
| 1 1/2" | Fully Threaded | 0.359" | 0.137" | 80,000 | ASME B18.6.3 | 25 | 000000000 | 00000 |
1/4"-20 | ||||||||
| 3/8" | Fully Threaded | 0.472" | 0.175" | 80,000 | __ | 25 | 000000000 | 00000 |
| 1/2" | Fully Threaded | 0.472" | 0.175" | 80,000 | __ | 25 | 000000000 | 00000 |
| 3/4" | Fully Threaded | 0.472" | 0.175" | 80,000 | __ | 25 | 000000000 | 00000 |
| 1" | Fully Threaded | 0.472" | 0.175" | 80,000 | __ | 25 | 000000000 | 00000 |
| 1 1/2" | Fully Threaded | 0.472" | 0.175" | 80,000 | __ | 25 | 000000000 | 00000 |
| 2" | Fully Threaded | 0.472" | 0.175" | 80,000 | ASME B18.6.3 | 10 | 000000000 | 00000 |
Steel Tamper-Resistant One-Way Round Head Screws
The S-shaped drive can be installed with a standard slotted driver, but requires a special tool for removal (sold separately). For removal tools, see one-way bits and drivers. Screws have a zinc plating for corrosion resistance in wet environments. Length is measured from under the head.
For technical drawings and 3-D models, click on a part number.
| Lg. | Threading | Head Dia. | Head Ht. | Tensile Strength, psi | Specifications Met | Pkg. Qty. | Pkg. | |
Zinc-Plated Steel | ||||||||
|---|---|---|---|---|---|---|---|---|
4-40 | ||||||||
| 1/4" | Fully Threaded | 0.211" | 0.086" | 60,000 | __ | 100 | 000000000 | 000000 |
| 3/8" | Fully Threaded | 0.211" | 0.086" | 60,000 | __ | 100 | 000000000 | 00000 |
| 1/2" | Fully Threaded | 0.211" | 0.086" | 60,000 | __ | 100 | 000000000 | 00000 |
| 3/4" | Fully Threaded | 0.211" | 0.086" | 60,000 | __ | 100 | 000000000 | 00000 |
6-32 | ||||||||
| 1/4" | Fully Threaded | 0.260" | 0.103" | 60,000 | __ | 100 | 000000000 | 00000 |
| 3/8" | Fully Threaded | 0.260" | 0.103" | 60,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
| 1/2" | Fully Threaded | 0.260" | 0.103" | 60,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
| 3/4" | Fully Threaded | 0.260" | 0.103" | 60,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
| 1" | Fully Threaded | 0.260" | 0.103" | 60,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
8-32 | ||||||||
| 1/4" | Fully Threaded | 0.309" | 0.120" | 60,000 | __ | 100 | 000000000 | 00000 |
| 3/8" | Fully Threaded | 0.309" | 0.120" | 60,000 | __ | 100 | 000000000 | 00000 |
| 1/2" | Fully Threaded | 0.309" | 0.120" | 60,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
| 3/4" | Fully Threaded | 0.309" | 0.120" | 60,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
| 1" | Fully Threaded | 0.309" | 0.120" | 60,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
| 1 1/2" | Fully Threaded | 0.309" | 0.120" | 60,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
10-24 | ||||||||
| 1/2" | Fully Threaded | 0.359" | 0.137" | 60,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
| 3/4" | Fully Threaded | 0.359" | 0.137" | 60,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
| 1" | Fully Threaded | 0.359" | 0.137" | 60,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
| 1 1/2" | Fully Threaded | 0.359" | 0.137" | 60,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
10-32 | ||||||||
| 1/4" | Fully Threaded | 0.359" | 0.137" | 60,000 | __ | 100 | 000000000 | 00000 |
| 3/8" | Fully Threaded | 0.359" | 0.137" | 60,000 | __ | 100 | 000000000 | 00000 |
| 1/2" | Fully Threaded | 0.359" | 0.137" | 60,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
| 3/4" | Fully Threaded | 0.359" | 0.137" | 60,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
| 1" | Fully Threaded | 0.359" | 0.137" | 60,000 | ASME B18.6.3 | 100 | 000000000 | 00000 |
| 1 1/2" | Fully Threaded | 0.359" | 0.137" | 60,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
1/4"-20 | ||||||||
| 3/8" | Fully Threaded | 0.472" | 0.175" | 60,000 | __ | 50 | 000000000 | 00000 |
| 1/2" | Fully Threaded | 0.472" | 0.175" | 60,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
| 3/4" | Fully Threaded | 0.472" | 0.175" | 60,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
| 1" | Fully Threaded | 0.472" | 0.175" | 60,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
| 1 1/2" | Fully Threaded | 0.472" | 0.175" | 60,000 | ASME B18.6.3 | 50 | 000000000 | 00000 |
One-Way Rounded Head Screws for Sheet Metal
The S-shaped drive can be installed with a standard slotted driver, but requires a special tool for removal. Made from 18-8 stainless steel, these screws are chemical resistant and may be mildly magnetic. They penetrate 0.025" and thinner sheet metal. Length is measured from under the head.
For technical drawings and 3-D models, click on a part number.
Head | |||||||
|---|---|---|---|---|---|---|---|
| Lg. | Dia. | Ht. | Drill Bit Size | Approximate Threads per Inch | Pkg. Qty. | Pkg. | |
18-8 Stainless Steel | |||||||
No. 6 | |||||||
| 1/2" | 0.26" | 0.103" | No. 32 | 18 | 100 | 000000000 | 000000 |
| 3/4" | 0.26" | 0.103" | No. 32 | 18 | 100 | 000000000 | 00000 |
| 1" | 0.26" | 0.103" | No. 32 | 18 | 50 | 000000000 | 00000 |
No. 8 | |||||||
| 1/2" | 0.309" | 0.12" | No. 29 | 15 | 50 | 000000000 | 00000 |
| 3/4" | 0.309" | 0.12" | No. 29 | 15 | 50 | 000000000 | 00000 |
| 1" | 0.309" | 0.12" | No. 29 | 15 | 50 | 000000000 | 00000 |
| 1 1/4" | 0.309" | 0.12" | No. 29 | 15 | 50 | 000000000 | 00000 |
| 1 1/2" | 0.309" | 0.12" | No. 29 | 15 | 50 | 000000000 | 0000 |
No. 10 | |||||||
| 1/2" | 0.359" | 0.137" | No. 21 | 12 | 50 | 000000000 | 00000 |
| 3/4" | 0.359" | 0.137" | No. 21 | 12 | 50 | 000000000 | 00000 |
| 1" | 0.359" | 0.137" | No. 21 | 12 | 50 | 000000000 | 00000 |
| 1 1/2" | 0.359" | 0.137" | No. 21 | 12 | 50 | 000000000 | 00000 |
| 2" | 0.359" | 0.137" | No. 21 | 12 | 25 | 000000000 | 00000 |
No. 12 | |||||||
| 1/2" | 0.425" | 1/8" | 3/16" | 11 | 50 | 000000000 | 00000 |
| 3/4" | 0.425" | 1/8" | 3/16" | 11 | 25 | 000000000 | 00000 |
| 1" | 0.425" | 1/8" | 3/16" | 11 | 25 | 000000000 | 0000 |
| 1 1/2" | 0.425" | 1/8" | 3/16" | 11 | 25 | 000000000 | 00000 |
| 2" | 0.425" | 1/8" | 3/16" | 11 | 25 | 000000000 | 00000 |
No. 14 | |||||||
| 1/2" | 0.472" | 0.175" | 5.5 mm | 10 | 50 | 000000000 | 00000 |
| 3/4" | 0.472" | 0.175" | 5.5 mm | 10 | 25 | 000000000 | 00000 |
| 1" | 0.472" | 0.175" | 5.5 mm | 10 | 25 | 000000000 | 00000 |
| 1 1/2" | 0.472" | 0.175" | 5.5 mm | 10 | 25 | 000000000 | 00000 |
| 2" | 0.472" | 0.175" | 5.5 mm | 10 | 25 | 000000000 | 00000 |
| 3" | 0.472" | 0.175" | 5.5 mm | 10 | 10 | 000000000 | 00000 |
One-Way Oval Head Screws for Sheet Metal
The S-shaped drive can be installed with a standard slotted driver, but requires a special tool for removal. Made from 18-8 stainless steel, they are chemical resistant and may be mildly magnetic. Screws penetrate 0.025" and thinner sheet metal. Length is measured from under the head.
For technical drawings and 3-D models, click on a part number.