About Tapping Screws
More
About Rounded Head Screws
More
About Thumb Screw and Binding Post Materials
More
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.
Tamper-Resistant One-Way Binding Barrels and Screws
Install these binding barrels and screws with a standard slotted screwdriver, but they require a special tool to remove. One-way removal tools are sold separately. Made from 18-8 stainless steel, these binding barrels and screws are chemical resistant and may be mildly magnetic. Barrel length and screw length are measured from under the head.
Black oxide binding barrels and screws have a matte-black finish that matches dark surfaces and reduces glare.
For technical drawings and 3-D models, click on a part number.
Barrel | Screw | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| For Material Thick. | Lg. | Dia. | Head Dia. | Head Ht. | Thread Dp. | Lg. | Head Dia. | Head Ht. | Pkg. Qty. | Pkg. | |
18-8 Stainless Steel | |||||||||||
10-24 | |||||||||||
| 1/2" to 5/8" | 1/4" | 1/4" | 7/16" | 7/64" | 7/32" | 15/32" | 7/16" | 7/64" | 5 | 000000000 | 00000 |
| 1/2" to 5/8" | 3/8" | 1/4" | 7/16" | 7/64" | 3/8" | 23/64" | 7/16" | 7/64" | 5 | 000000000 | 0000 |
| 5/8" to 3/4" | 3/8" | 1/4" | 7/16" | 7/64" | 5/16" | 15/32" | 7/16" | 7/64" | 5 | 000000000 | 0000 |
| 5/8" to 3/4" | 1/2" | 1/4" | 7/16" | 7/64" | 3/8" | 3/8" | 7/16" | 7/64" | 5 | 000000000 | 0000 |
| 3/4" to 7/8" | 1/2" | 1/4" | 7/16" | 7/64" | 3/8" | 15/32" | 7/16" | 7/64" | 5 | 000000000 | 0000 |
| 3/4" to 1" | 1/2" | 1/4" | 7/16" | 7/64" | 3/8" | 9/16" | 7/16" | 7/64" | 5 | 000000000 | 0000 |
| 7/8" to 1 1/8" | 5/8" | 1/4" | 7/16" | 7/64" | 9/16" | 3/4" | 7/16" | 7/64" | 5 | 000000000 | 0000 |
| 7/8" to 1 1/8" | 3/4" | 1/4" | 7/16" | 7/64" | 9/16" | 1/2" | 7/16" | 7/64" | 5 | 000000000 | 0000 |
| 1 1/8" to 1 3/8" | 3/4" | 1/4" | 7/16" | 7/64" | 17/32" | 3/4" | 7/16" | 7/64" | 5 | 000000000 | 0000 |
| 1 1/8" to 1 3/8" | 1" | 1/4" | 7/16" | 7/64" | 9/16" | 1/2" | 7/16" | 7/64" | 5 | 000000000 | 0000 |
| 1 3/8" to 1 5/8" | 1" | 1/4" | 7/16" | 7/64" | 17/32" | 3/4" | 7/16" | 7/64" | 5 | 000000000 | 0000 |
| 1 7/16" to 1 3/4" | 1" | 1/4" | 7/16" | 7/64" | 9/16" | 15/16" | 7/16" | 7/64" | 5 | 000000000 | 0000 |
| 1 5/8" to 1 7/8" | 1" | 1/4" | 7/16" | 7/64" | 9/16" | 1 3/16" | 7/16" | 7/64" | 5 | 000000000 | 0000 |
| 1 3/4" to 2" | 1" | 1/4" | 7/16" | 7/64" | 9/16" | 1 5/16" | 7/16" | 7/64" | 5 | 000000000 | 0000 |
Black-Oxide 18-8 Stainless Steel | |||||||||||
10-24 | |||||||||||
| 1/2" to 5/8" | 1/4" | 1/4" | 7/16" | 7/64" | 7/32" | 15/32" | 7/16" | 7/64" | 5 | 000000000 | 00000 |
| 5/8" to 3/4" | 1/2" | 1/4" | 7/16" | 7/64" | 3/8" | 3/8" | 7/16" | 7/64" | 5 | 000000000 | 00000 |
| 3/4" to 7/8" | 5/8" | 1/4" | 7/16" | 7/64" | 9/16" | 1/2" | 7/16" | 7/64" | 5 | 000000000 | 0000 |
| 7/8" to 1 1/8" | 3/4" | 1/4" | 7/16" | 7/64" | 9/16" | 1/2" | 7/16" | 7/64" | 5 | 000000000 | 00000 |
| 1" to 1 3/8" | 3/4" | 1/4" | 7/16" | 7/64" | 9/16" | 3/4" | 7/16" | 7/64" | 5 | 000000000 | 00000 |
| 1 1/8" to 1 3/8" | 1" | 1/4" | 7/16" | 7/64" | 9/16" | 1/2" | 7/16" | 7/64" | 5 | 000000000 | 00000 |
| 1 1/4" to 1 5/8" | 1" | 1/4" | 7/16" | 7/64" | 9/16" | 3/4" | 7/16" | 7/64" | 5 | 000000000 | 00000 |
| 1 7/16" to 1 3/4" | 1" | 1/4" | 7/16" | 7/64" | 9/16" | 15/16" | 7/16" | 7/64" | 5 | 000000000 | 00000 |
| 1 3/4" to 2" | 1" | 1/4" | 7/16" | 7/64" | 9/16" | 1 5/16" | 7/16" | 7/64" | 5 | 000000000 | 00000 |
| One-Way Screw Removal Tool | 0000000 | Each | 000000 |