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.

3D CAD models availableFor 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 90342A111 $2.33

3/8" Fully Threaded Coarse 0.183" 0.112" 0.03" 3/32" 180,000 90342A112 2.35

1/2" Fully Threaded Coarse 0.183" 0.112" 0.03" 3/32" 180,000 90342A113 2.35

6-32

1/4" Fully Threaded Coarse 0.226" 0.138" 0.04" 7/64" 180,000 90342A114 2.24

3/8" Fully Threaded Coarse 0.226" 0.138" 0.04" 7/64" 180,000 90342A115 2.25

1/2" Fully Threaded Coarse 0.226" 0.138" 0.04" 7/64" 180,000 90342A116 2.26

8-32

3/8" Fully Threaded Coarse 0.27" 0.164" 3/64" 9/64" 180,000 90342A117 2.30

1/2" Fully Threaded Coarse 0.27" 0.164" 3/64" 9/64" 180,000 90342A118 2.31

5/8" Fully Threaded Coarse 0.27" 0.164" 3/64" 9/64" 180,000 90342A119 2.33

3/4" Fully Threaded Coarse 0.27" 0.164" 3/64" 9/64" 180,000 90342A120 2.37

1" Fully Threaded Coarse 0.27" 0.164" 3/64" 9/64" 180,000 90342A121 2.38

10-32

3/8" Fully Threaded Fine 5/16" 0.19" 3/64" 5/32" 180,000 90342A122 2.35

1/2" Fully Threaded Fine 5/16" 0.19" 3/64" 5/32" 180,000 90342A123 2.37

3/4" Fully Threaded Fine 5/16" 0.19" 3/64" 5/32" 180,000 90342A124 2.42

1" Fully Threaded Fine 5/16" 0.19" 3/64" 5/32" 180,000 90342A125 2.46

1/4"-20

3/8" Fully Threaded Coarse 3/8" 1/4" 1/16" 3/16" 180,000 90342A126 2.59

1/2" Fully Threaded Coarse 3/8" 1/4" 1/16" 3/16" 180,000 90342A127 2.53

3/4" Fully Threaded Coarse 3/8" 1/4" 1/16" 3/16" 180,000 90342A128 2.60

1" Fully Threaded Coarse 3/8" 1/4" 1/16" 3/16" 180,000 90342A129 2.69

1 1/4" Fully Threaded Coarse 3/8" 1/4" 1/16" 3/16" 180,000 90342A130 2.82

1 1/2" Fully Threaded Coarse 3/8" 1/4" 1/16" 3/16" 180,000 90342A131 2.97