**Note pre-packaged quantity before adding to cart**

View the large selection of square-head machine bolts that we have available below. We also carry square-head screws, decorative lag bolts, and more.

sort-descending
  • 1/4-20 x 1-1/8" Machine Bolt
    1/4-20 x 1-1/8" Machine Bolt
    Write your review
    $0.20
  • 1/4-20 x 2" machine bolt (see description)
    1/4-20 x 2" machine bolt (see description)
    Write your review
    $0.15
  • 1/4-20 x 2.5" machine bolt
    1/4-20 x 2.5" machine bolt
    Write your review
    $0.40
  • 1/4-20 x 3" machine bolt
    1/4-20 x 3" machine bolt
    Write your review
    $0.40
  • 1/4-20 x 3.25" machine bolt
    1/4-20 x 3.25" machine bolt
    Write your review
    $0.60
  • 1/4-20 x 3.5" machine bolt (partial thread)
    1/4-20 x 3.5" machine bolt (partial thread)
    Write your review
    $0.85
  • 1/4-20 x 4" machine bolt
    1/4-20 x 4" machine bolt
    Write your review
    $0.85
  • 1/4-20 x 4.5" machine bolt (partial thread)
    1/4-20 x 4.5" machine bolt (partial thread)
    Write your review
    $1.25
  • 1/4-20 x 4.75" machine bolt
    1/4-20 x 4.75" machine bolt
    Write your review
    $1.30
  • 1/4-20 x 5" machine bolt (partial thread)
    1/4-20 x 5" machine bolt (partial thread)
    Write your review
    $1.50
  • 1/4-20 x 6" machine bolt (full thread)
    1/4-20 x 6" machine bolt (full thread)
    Write your review
    $1.70
  • 5/16-18 x 3" machine Bolts
    5/16-18 x 3" machine Bolts
    Write your review
    $1.00
  • 5/16-18 x 3.5" machine Bolts
    5/16-18 x 3.5" machine Bolts
    Write your review
    $1.50
  • 5/16-18 x 4" machine Bolts
    5/16-18 x 4" machine Bolts
    Write your review
    $1.70
  • 5/16-18 x 5" machine Bolts
    5/16-18 x 5" machine Bolts
    Write your review
    $2.25
  • 5/16-18 x 5.5" machine Bolts
    5/16-18 x 5.5" machine Bolts
    Write your review
    $2.50
  • 5/16-18 x 6" machine Bolts
    5/16-18 x 6" machine Bolts
    Write your review
    $2.75
  • 5/16-18 x 8.5" machine Bolts
    5/16-18 x 8.5" machine Bolts
    Write your review
    $5.00