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About Rounded Head Screws
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Vibration-Resistant Sealing Rounded Head Screws


A nylon patch bonded to the threads of these screws adds friction to prevent loosening from vibration while an O-ring prevents leaks and seals out contaminants. Made from 18-8 stainless steel, they have good chemical resistance and may be mildly magnetic. They’re passivated for added protection against oxidation and corrosion. The silicone O-ring withstands salt water and is good for a wide range of temperatures. 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. | For Max. Hole Dia. | Drive Size | Tensile Strength, psi | Thread Locker Temp. Range, °F | O-Ring Temp. Range, °F | Max. Pressure, psi | Specifications Met | Pkg. Qty. | Pkg. | |
18-8 Stainless Steel | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
4-40 | |||||||||||||
1/2" | Fully Threaded | 0.238" | 0.080" | 0.127" | No. 1 | 70,000 | -40° to 225° | -80° to 400° | 1,500 | MIL-DTL-18240, MS3212-5L, NASM3212, NASM82496 | 5 | 000000000 | 00000 |