About Socket Head Screws
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Stainless Steel Socket Head Screws with Split Lock Washer
Screws are 18-8 stainless steel for good chemical resistance. They may be mildly magnetic. Also known as Sems screws, they have a permanently attached but freely rotating split lock washer that adds tension to resist loosening from vibration. All screws meet ASTM F837 specifications and testing requirements for material quality. Length is measured from under the head.
Coarse threads are the industry standard; choose these screws if you don’t know the threads per inch. Fine threads are closely spaced to prevent loosening from vibration. They are not compatible with coarse threads.
For technical drawings and 3-D models, click on a part number.
Head | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Lg. | Threading | Thread Spacing  | Dia. | Ht. | Washer Thick. | Drive Size | Tensile Strength, psi | Specifications Met | Each | |
18-8 Stainless Steel | ||||||||||
6-32 | ||||||||||
| 1/4" | Fully Threaded | Coarse | 0.226" | 0.138" | 0.04" | 7/64" | 70,000 | ASTM F837 | 000000000 | 00000 |
| 3/8" | Fully Threaded | Coarse | 0.226" | 0.138" | 0.04" | 7/64" | 70,000 | ASTM F837 | 000000000 | 0000 |
| 1/2" | Fully Threaded | Coarse | 0.226" | 0.138" | 0.04" | 7/64" | 70,000 | ASTM F837 | 000000000 | 0000 |
| 3/4" | Fully Threaded | Coarse | 0.226" | 0.138" | 0.04" | 7/64" | 70,000 | ASTM F837 | 000000000 | 0000 |
8-32 | ||||||||||
| 3/8" | Fully Threaded | Coarse | 0.27" | 0.164" | 3/64" | 9/64" | 70,000 | ASTM F837 | 000000000 | 0000 |
| 1/2" | Fully Threaded | Coarse | 0.27" | 0.164" | 3/64" | 9/64" | 70,000 | ASTM F837 | 000000000 | 0000 |
| 5/8" | Fully Threaded | Coarse | 0.27" | 0.164" | 3/64" | 9/64" | 70,000 | ASTM F837 | 000000000 | 0000 |
| 3/4" | Fully Threaded | Coarse | 0.27" | 0.164" | 3/64" | 9/64" | 70,000 | ASTM F837 | 000000000 | 0000 |
| 1" | Fully Threaded | Coarse | 0.27" | 0.164" | 3/64" | 9/64" | 70,000 | ASTM F837 | 000000000 | 0000 |
10-32 | ||||||||||
| 1/2" | Fully Threaded | Fine | 5/16" | 0.19" | 3/64" | 5/32" | 70,000 | ASTM F837 | 000000000 | 0000 |
| 5/8" | Fully Threaded | Fine | 5/16" | 0.19" | 3/64" | 5/32" | 70,000 | ASTM F837 | 000000000 | 0000 |
| 3/4" | Fully Threaded | Fine | 5/16" | 0.19" | 3/64" | 5/32" | 70,000 | ASTM F837 | 000000000 | 0000 |
| 1" | Fully Threaded | Fine | 5/16" | 0.19" | 3/64" | 5/32" | 70,000 | ASTM F837 | 000000000 | 0000 |
1/4"-20 | ||||||||||
| 1/2" | Fully Threaded | Coarse | 3/8" | 1/4" | 1/16" | 3/16" | 70,000 | ASTM F837 | 000000000 | 0000 |
| 5/8" | Fully Threaded | Coarse | 3/8" | 1/4" | 1/16" | 3/16" | 70,000 | ASTM F837 | 000000000 | 0000 |
| 3/4" | Fully Threaded | Coarse | 3/8" | 1/4" | 1/16" | 3/16" | 70,000 | ASTM F837 | 000000000 | 0000 |
| 1" | Fully Threaded | Coarse | 3/8" | 1/4" | 1/16" | 3/16" | 70,000 | ASTM F837 | 000000000 | 0000 |
| 1 1/4" | Fully Threaded | Coarse | 3/8" | 1/4" | 1/16" | 3/16" | 70,000 | ASTM F837 | 000000000 | 0000 |
Alloy Steel Socket Head Screws with Split Lock Washer
Screws are alloy steel with a tensile strength of 180,000 psi, making them stronger than Grade 8 steel screws and more than two and a half times stronger than stainless steel screws with a split lock washer. Their black-oxide finish provides mild corrosion resistance in dry environments. Also known as Sems screws, they have a permanently attached but freely rotating split lock washer that adds tension to resist loosening from vibration. Length is measured from under the head.
Coarse threads are the industry standard; choose these screws if you don’t know the threads per inch. Fine threads are closely spaced to prevent loosening from vibration. They are not compatible with coarse threads.
For technical drawings and 3-D models, click on a part number.
Head | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Lg. | Threading | Thread Spacing | Dia. | Ht. | Washer Thick. | Drive Size | Tensile Strength, psi | Each | |
Black-Oxide Alloy Steel | |||||||||
4-40 | |||||||||
| 1/4" | Fully Threaded | Coarse | 0.183" | 0.112" | 0.03" | 3/32" | 180,000 | 000000000 | 00000 |
| 3/8" | Fully Threaded | Coarse | 0.183" | 0.112" | 0.03" | 3/32" | 180,000 | 000000000 | 0000 |
| 1/2" | Fully Threaded | Coarse | 0.183" | 0.112" | 0.03" | 3/32" | 180,000 | 000000000 | 0000 |
6-32 | |||||||||
| 1/4" | Fully Threaded | Coarse | 0.226" | 0.138" | 0.04" | 7/64" | 180,000 | 000000000 | 0000 |
| 3/8" | Fully Threaded | Coarse | 0.226" | 0.138" | 0.04" | 7/64" | 180,000 | 000000000 | 0000 |
| 1/2" | Fully Threaded | Coarse | 0.226" | 0.138" | 0.04" | 7/64" | 180,000 | 000000000 | 0000 |
8-32 | |||||||||
| 3/8" | Fully Threaded | Coarse | 0.27" | 0.164" | 3/64" | 9/64" | 180,000 | 000000000 | 0000 |
| 1/2" | Fully Threaded | Coarse | 0.27" | 0.164" | 3/64" | 9/64" | 180,000 | 000000000 | 0000 |
| 5/8" | Fully Threaded | Coarse | 0.27" | 0.164" | 3/64" | 9/64" | 180,000 | 000000000 | 0000 |
| 3/4" | Fully Threaded | Coarse | 0.27" | 0.164" | 3/64" | 9/64" | 180,000 | 000000000 | 0000 |
| 1" | Fully Threaded | Coarse | 0.27" | 0.164" | 3/64" | 9/64" | 180,000 | 000000000 | 0000 |
10-32 | |||||||||
| 3/8" | Fully Threaded | Fine | 5/16" | 0.19" | 3/64" | 5/32" | 180,000 | 000000000 | 0000 |
| 1/2" | Fully Threaded | Fine | 5/16" | 0.19" | 3/64" | 5/32" | 180,000 | 000000000 | 0000 |
| 3/4" | Fully Threaded | Fine | 5/16" | 0.19" | 3/64" | 5/32" | 180,000 | 000000000 | 0000 |
| 1" | Fully Threaded | Fine | 5/16" | 0.19" | 3/64" | 5/32" | 180,000 | 000000000 | 0000 |
1/4"-20 | |||||||||
| 3/8" | Fully Threaded | Coarse | 3/8" | 1/4" | 1/16" | 3/16" | 180,000 | 000000000 | 0000 |
| 1/2" | Fully Threaded | Coarse | 3/8" | 1/4" | 1/16" | 3/16" | 180,000 | 000000000 | 0000 |
| 3/4" | Fully Threaded | Coarse | 3/8" | 1/4" | 1/16" | 3/16" | 180,000 | 000000000 | 0000 |
| 1" | Fully Threaded | Coarse | 3/8" | 1/4" | 1/16" | 3/16" | 180,000 | 000000000 | 0000 |
| 1 1/4" | Fully Threaded | Coarse | 3/8" | 1/4" | 1/16" | 3/16" | 180,000 | 000000000 | 0000 |
| 1 1/2" | Fully Threaded | Coarse | 3/8" | 1/4" | 1/16" | 3/16" | 180,000 | 000000000 | 0000 |
Socket Head Screws with Flat Washer
A freely rotating washer distributes pressure over a wider area than a flange, preventing damage to your material's surface. With a tensile strength of 170,000 psi, these alloy steel screws are stronger than Grade 8 steel screws. Their black-oxide finish provides mild corrosion resistance in dry environments. Made to dimensional and material quality standards, all meet ASTM A574 and some also meet ASME B18.3. Length is measured from under the head.
Coarse threads are the industry standard; choose these screws if you don’t know the threads per inch. Fine threads are closely spaced to prevent loosening from vibration. They are not compatible with coarse threads.
For technical drawings and 3-D models, click on a part number.
Head | Washer | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Lg. | Threading | Min. Thread Lg. | Thread Spacing | Dia. | Ht. | OD | Thick. | Drive Size | Tensile Strength, psi | Specifications Met | Pkg. Qty. | Pkg. | |
Black-Oxide Alloy Steel | |||||||||||||
4-40 | |||||||||||||
| 1/4" | Fully Threaded | __ | Coarse | 0.183" | 0.112" | 5/16" | 0.032" | 3/32" | 170,000 | ASTM A574 | 1 | 000000000 | 00000 |
| 1/2" | Fully Threaded | __ | Coarse | 0.183" | 0.112" | 5/16" | 0.032" | 3/32" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 3/4" | Fully Threaded | __ | Coarse | 0.183" | 0.112" | 5/16" | 0.032" | 3/32" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 1" | Partially Threaded | 3/4" | Coarse | 0.183" | 0.112" | 5/16" | 0.032" | 3/32" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
6-32 | |||||||||||||
| 1/4" | Fully Threaded | __ | Coarse | 0.226" | 0.138" | 3/8" | 0.049" | 7/64" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 1/2" | Fully Threaded | __ | Coarse | 0.226" | 0.138" | 3/8" | 0.049" | 7/64" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 3/4" | Fully Threaded | __ | Coarse | 0.226" | 0.138" | 3/8" | 0.049" | 7/64" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 1" | Fully Threaded | __ | Coarse | 0.226" | 0.138" | 3/8" | 0.049" | 7/64" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 1 1/4" | Partially Threaded | 3/4" | Coarse | 0.226" | 0.138" | 3/8" | 0.049" | 7/64" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
8-32 | |||||||||||||
| 1/2" | Fully Threaded | __ | Coarse | 0.27" | 0.164" | 3/8" | 0.032" | 9/64" | 170,000 | ASME B18.3, ASTM A574 | 10 | 000000000 | 00000 |
| 3/4" | Fully Threaded | __ | Coarse | 0.27" | 0.164" | 7/16" | 0.049" | 9/64" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 1" | Fully Threaded | __ | Coarse | 0.27" | 0.164" | 7/16" | 0.049" | 9/64" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 1 1/4" | Partially Threaded | 7/8" | Coarse | 0.27" | 0.164" | 7/16" | 0.049" | 9/64" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 1 1/2" | Partially Threaded | 1 1/8" | Coarse | 0.27" | 0.164" | 7/16" | 0.049" | 9/64" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
10-24 | |||||||||||||
| 1/2" | Fully Threaded | __ | Coarse | 5/16" | 0.19" | 1/2" | 0.049" | 5/32" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 3/4" | Fully Threaded | __ | Coarse | 5/16" | 0.19" | 1/2" | 0.049" | 5/32" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 1" | Fully Threaded | __ | Coarse | 5/16" | 0.19" | 1/2" | 0.049" | 5/32" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 1 1/4" | Partially Threaded | 7/8" | Coarse | 5/16" | 0.19" | 1/2" | 0.049" | 5/32" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 1 1/2" | Partially Threaded | 1 1/8" | Coarse | 5/16" | 0.19" | 1/2" | 0.049" | 5/32" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
10-32 | |||||||||||||
| 1/2" | Fully Threaded | __ | Fine | 5/16" | 0.19" | 7/16" | 0.036" | 5/32" | 170,000 | ASME B18.3, ASTM A574 | 5 | 000000000 | 00000 |
| 3/4" | Fully Threaded | __ | Fine | 5/16" | 0.19" | 7/16" | 0.036" | 5/32" | 170,000 | ASME B18.3, ASTM A574 | 5 | 000000000 | 00000 |
| 1" | Fully Threaded | __ | Fine | 5/16" | 0.19" | 7/16" | 0.036" | 5/32" | 170,000 | ASME B18.3, ASTM A574 | 5 | 000000000 | 00000 |
| 1 1/4" | Partially Threaded | 7/8" | Fine | 5/16" | 0.19" | 1/2" | 0.049" | 5/32" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 1 1/2" | Partially Threaded | 1 1/8" | Fine | 5/16" | 0.19" | 1/2" | 0.049" | 5/32" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
1/4"-20 | |||||||||||||
| 1/2" | Fully Threaded | __ | Coarse | 3/8" | 1/4" | 1/2" | 1/16" | 3/16" | 170,000 | ASME B18.3, ASTM A574 | 5 | 000000000 | 00000 |
| 3/4" | Fully Threaded | __ | Coarse | 3/8" | 1/4" | 1/2" | 1/16" | 3/16" | 170,000 | ASME B18.3, ASTM A574 | 5 | 000000000 | 00000 |
| 1" | Fully Threaded | __ | Coarse | 3/8" | 1/4" | 1/2" | 1/16" | 3/16" | 170,000 | ASME B18.3, ASTM A574 | 5 | 000000000 | 00000 |
| 1 1/2" | Fully Threaded | __ | Coarse | 3/8" | 1/4" | 1/2" | 1/16" | 3/16" | 170,000 | ASME B18.3, ASTM A574 | 5 | 000000000 | 00000 |
5/16"-18 | |||||||||||||
| 3/4" | Fully Threaded | __ | Coarse | 15/32" | 5/16" | 5/8" | 1/16" | 1/4" | 170,000 | ASME B18.3, ASTM A574 | 5 | 000000000 | 00000 |
| 1" | Fully Threaded | __ | Coarse | 15/32" | 5/16" | 5/8" | 1/16" | 1/4" | 170,000 | ASME B18.3, ASTM A574 | 5 | 000000000 | 00000 |
| 1 1/2" | Fully Threaded | __ | Coarse | 15/32" | 5/16" | 5/8" | 1/16" | 1/4" | 170,000 | ASME B18.3, ASTM A574 | 5 | 000000000 | 00000 |
3/8"-16 | |||||||||||||
| 1" | Fully Threaded | __ | Coarse | 9/16" | 3/8" | 13/16" | 0.065" | 5/16" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 1 1/4" | Fully Threaded | __ | Coarse | 9/16" | 3/8" | 13/16" | 0.065" | 5/16" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 1 1/2" | Fully Threaded | __ | Coarse | 9/16" | 3/8" | 13/16" | 0.065" | 5/16" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
3/8"-24 | |||||||||||||
| 1" | Fully Threaded | __ | Fine | 9/16" | 3/8" | 13/16" | 0.065" | 5/16" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 1 1/4" | Fully Threaded | __ | Fine | 9/16" | 3/8" | 13/16" | 0.065" | 5/16" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 1 1/2" | Fully Threaded | __ | Fine | 9/16" | 3/8" | 13/16" | 0.065" | 5/16" | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
M3 | |||||||||||||
| 6mm | Fully Threaded | __ | Coarse | 5.68mm | 3mm | 10mm | 1.2mm | 2.5 mm | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 8mm | Fully Threaded | __ | Coarse | 5.68mm | 3mm | 10mm | 1.2mm | 2.5 mm | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 10mm | Fully Threaded | __ | Coarse | 5.68mm | 3mm | 10mm | 1.2mm | 2.5 mm | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 12mm | Fully Threaded | __ | Coarse | 5.68mm | 3mm | 10mm | 1.2mm | 2.5 mm | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
M4 | |||||||||||||
| 6mm | Fully Threaded | __ | Coarse | 7.22mm | 4mm | 12mm | 1.4mm | 3 mm | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 8mm | Fully Threaded | __ | Coarse | 7.22mm | 4mm | 12mm | 1.4mm | 3 mm | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 10mm | Fully Threaded | __ | Coarse | 7.22mm | 4mm | 12mm | 1.4mm | 3 mm | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 12mm | Fully Threaded | __ | Coarse | 7.22mm | 4mm | 12mm | 1.4mm | 3 mm | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
M5 | |||||||||||||
| 6mm | Fully Threaded | __ | Coarse | 8.72mm | 5mm | 15mm | 1.8mm | 4 mm | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 8mm | Fully Threaded | __ | Coarse | 8.72mm | 5mm | 15mm | 1.8mm | 4 mm | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 10mm | Fully Threaded | __ | Coarse | 8.72mm | 5mm | 15mm | 1.8mm | 4 mm | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |
| 12mm | Fully Threaded | __ | Coarse | 8.72mm | 5mm | 15mm | 1.8mm | 4 mm | 170,000 | ASTM A574 | 1 | 000000000 | 0000 |