About Hex Head Screws and Bolts
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Medium-Strength Steel Hex Head Screws with Lock Washer
Also known as Sems screws, these screws have a washer that’s permanently attached but rotates freely. The washer has sharp teeth around the outside edge that bite into the screw and the material it’s installed on for vibration resistance. Twice as strong as low-strength steel screws, these Grade 5.1 screws are suitable for fastening most machinery and equipment. These screws and washers are heat treated together to ensure they have a compatible hardness. A zinc plating helps prevent corrosion in wet environments. All meet ASME specifications for dimensions and SAE specifications for material quality. Length is measured from under the head.
Certificates with a traceable lot number are available for these products. Download certificates from ORDER HISTORY after your order ships.
Head | Washer | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Lg. | Threading | Thread Spacing  | Wd. | Ht. | OD | Thick. | Material | Tensile Strength, psi | Specifications Met | Pkg. Qty. | Pkg. | |
Zinc-Plated Grade 5.1 Steel | ||||||||||||
1/4"-20 | ||||||||||||
| 1/2" | Fully Threaded | Coarse | 7/16" | 3/16" | 0.475" | 0.025" | Zinc-Plated Steel | 120,000 | ASME B18.13, SAE J429 | 25 | 000000000 | 000000 |
| 3/4" | Fully Threaded | Coarse | 7/16" | 3/16" | 0.475" | 0.025" | Zinc-Plated Steel | 120,000 | ASME B18.13, SAE J429 | 25 | 000000000 | 00000 |
| 1" | Fully Threaded | Coarse | 7/16" | 3/16" | 0.475" | 0.025" | Zinc-Plated Steel | 120,000 | ASME B18.13, SAE J429 | 25 | 000000000 | 00000 |
3/8"-16 | ||||||||||||
| 1" | Fully Threaded | Coarse | 9/16" | 9/32" | 0.66" | 0.035" | Zinc-Plated Steel | 120,000 | ASME B18.13, SAE J429 | 10 | 000000000 | 00000 |
| 1 1/4" | Fully Threaded | Coarse | 9/16" | 9/32" | 0.66" | 0.035" | Zinc-Plated Steel | 120,000 | ASME B18.13, SAE J429 | 10 | 000000000 | 00000 |
| 1 1/2" | Fully Threaded | Coarse | 9/16" | 9/32" | 0.66" | 0.035" | Zinc-Plated Steel | 120,000 | ASME B18.13, SAE J429 | 10 | 000000000 | 00000 |