About Flat Head Screws
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Tamper-Resistant Torx Flat Head Screws
With a tamper-resistant Torx or Torx Plus drive (also known as a pin-in Torx or Torx Plus drive), these screws are difficult to remove without special tools. They’re angled under the head to sit flush within countersunk holes. Length is measured from the top of the head.
Install Torx screws using tamper-resistant Torx drivers and bits.
Torx Plus screws have more points of contact than hex drive screws, so you can tighten them with less slippage and damage to their recess. These tamper-resistant Torx Plus screws have five lobes. Install them with tamper-resistant Torx Plus or tamper-resistant pentalobe drivers and bits.
18-8 stainless steel screws have good chemical resistance and may be mildly magnetic.
Alloy steel screws are roughly twice as strong as stainless steel screws.
Screws with an undercut profile have a shallow head for use in thin materials.
Passivated stainless steel screws provide added protection against oxidation and corrosion.
For technical drawings and 3-D models, click on a part number.
| Lg. | Threading | Flat Head Profile | Head Dia. | Head Ht. | Drive Size | Finish | Tensile Strength, psi  | Specifications Met | Pkg. Qty. | Pkg. | |
18-8 Stainless Steel—Tamper-Resistant Torx | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
8-32 | |||||||||||
| 2" | Fully Threaded | Standard | 0.359" | 0.112" | T20 | Passivated | 70,000 | ASME B18.3 | 10 | 000000000 | 00000 |
1/4"-20 | |||||||||||
| 1 3/4" | Fully Threaded | Standard | 0.531" | 0.161" | T30 | Passivated | 70,000 | ASME B18.3 | 10 | 000000000 | 00000 |
12-24 | |||||||||||
| 1/2" | Fully Threaded | Undercut | 0.412" | 0.092" | T20 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 3/4" | Fully Threaded | Standard | 0.438" | 0.132" | T25 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 1" | Fully Threaded | Standard | 0.438" | 0.132" | T25 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
18-8 Stainless Steel—Tamper-Resistant Torx Plus | |||||||||||
6-32 | |||||||||||
| 1/4" | Fully Threaded | Undercut | 0.279" | 0.059" | IPR10 | Passivated | 70,000 | ASME B18.3 | 50 | 000000000 | 00000 |
| 3/8" | Fully Threaded | Standard | 0.307" | 0.097" | IPR15 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 0000 |
| 1/2" | Fully Threaded | Standard | 0.307" | 0.097" | IPR15 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 0000 |
| 3/4" | Fully Threaded | Standard | 0.307" | 0.097" | IPR15 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 1" | Fully Threaded | Standard | 0.307" | 0.097" | IPR15 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 1 1/2" | Fully Threaded | Standard | 0.307" | 0.097" | IPR15 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
8-32 | |||||||||||
| 1/4" | Fully Threaded | Undercut | 0.332" | 0.070" | IPR15 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 0000 |
| 1/2" | Fully Threaded | Standard | 0.359" | 0.112" | IPR20 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 3/4" | Fully Threaded | Standard | 0.359" | 0.112" | IPR20 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 0000 |
| 1" | Fully Threaded | Standard | 0.359" | 0.112" | IPR20 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 1 1/2" | Fully Threaded | Standard | 0.359" | 0.112" | IPR20 | Passivated | 70,000 | ASME B18.3 | 10 | 000000000 | 0000 |
10-24 | |||||||||||
| 3/8" | Fully Threaded | Standard | 0.411" | 0.127" | IPR25 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 0000 |
| 1/2" | Fully Threaded | Standard | 0.411" | 0.127" | IPR25 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 3/4" | Fully Threaded | Standard | 0.411" | 0.127" | IPR25 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 1" | Fully Threaded | Standard | 0.411" | 0.127" | IPR25 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 1 1/4" | Fully Threaded | Standard | 0.411" | 0.127" | IPR25 | Passivated | 70,000 | ASME B18.3 | 10 | 000000000 | 0000 |
10-32 | |||||||||||
| 3/8" | Fully Threaded | Standard | 0.411" | 0.127" | IPR25 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 1/2" | Fully Threaded | Standard | 0.411" | 0.127" | IPR25 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 3/4" | Fully Threaded | Standard | 0.411" | 0.127" | IPR25 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 1" | Fully Threaded | Standard | 0.411" | 0.127" | IPR25 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
1/4"-20 | |||||||||||
| 3/8" | Fully Threaded | Undercut | 0.507" | 0.107" | IPR27 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 1/2" | Fully Threaded | Undercut | 0.507" | 0.107" | IPR27 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 5/8" | Fully Threaded | Standard | 0.531" | 0.161" | IPR30 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 3/4" | Fully Threaded | Standard | 0.531" | 0.161" | IPR30 | Passivated | 70,000 | ASME B18.3 | 10 | 000000000 | 0000 |
| 1" | Fully Threaded | Standard | 0.531" | 0.161" | IPR30 | Passivated | 70,000 | ASME B18.3 | 10 | 000000000 | 0000 |
| 1 1/4" | Fully Threaded | Standard | 0.531" | 0.161" | IPR30 | Passivated | 70,000 | ASME B18.3 | 10 | 000000000 | 0000 |
| 1 1/2" | Fully Threaded | Standard | 0.531" | 0.161" | IPR30 | Passivated | 70,000 | ASME B18.3 | 10 | 000000000 | 00000 |
12-24 | |||||||||||
| 1/2" | Fully Threaded | Undercut | 0.438" | 0.092" | IPR20 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 3/4" | Fully Threaded | Standard | 0.438" | 0.132" | IPR25 | Passivated | 70,000 | ASME B18.3 | 25 | 000000000 | 00000 |
Alloy Steel—Tamper-Resistant Torx Plus | |||||||||||
1/4"-20 | |||||||||||
| 3/8" | Fully Threaded | Undercut | 0.507" | 0.107" | IPR27 | Black Oxide | 160,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 1/2" | Fully Threaded | Undercut | 0.507" | 0.107" | IPR27 | Black Oxide | 160,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 3/4" | Fully Threaded | Standard | 0.507" | 0.161" | IPR27 | Black Oxide | 160,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 1" | Fully Threaded | Standard | 0.531" | 0.161" | IPR30 | Black Oxide | 160,000 | ASME B18.3 | 25 | 000000000 | 00000 |
| 1 1/4" | Fully Threaded | Standard | 0.531" | 0.161" | IPR30 | Black Oxide | 160,000 | ASME B18.3 | 25 | 000000000 | 00000 |