This store requires javascript to be enabled for some features to work correctly.

Free shipping - all domestic orders over $40

Square Head Bolts

Square head bolts, also called machine bolts are threaded to receive a nut. These decorative bolts come in smooth, hammered and pyramid head styles. To shop by head style click on the image below to see all available sizes in that head appearance.

Our square head bolts are available in diameters from #10 - 3/4" and lengths from 3/4" - 12" depending on your chosen diameter. 

All bolts are partial threaded unless custom ordered as full thread. To ask a question or request customizations such as full thread please reach out to us via office@oldwestiron.com.


For Extra Long Lengths or custom Lengths

Custom Bolts

We offer custom extra-long bolts and lags in full or partial thread options — up to 72" in length (and beyond for partial thread).
We also offer custom grades, decorative finishes, and specialty threading upon request.

  1. 1/4" Dia. Smooth Square Head Bolt Nuts & Bolts Bolt
    1/4" Dia. Smooth Square Head Bolt
    from $0.86
  2. 1/4" Dia. Hammered Square Head Bolt
    1/4" Dia. Hammered Square Head Bolt
    from $2.25
  3. 1/4" Dia. Pyramid Square Head Bolt
    1/4" Dia. Pyramid Square Head Bolt
    from $2.90
  4. 5/16" Dia. Smooth Square Head Bolt
    5/16" Dia. Smooth Square Head Bolt
    from $1.06
  5. 5/16" Dia. Hammered Square Head Bolt
    5/16" Dia. Hammered Square Head Bolt
    from $2.57
  6. 5/16" Dia. Pyramid Square Head Bolt
    5/16" Dia. Pyramid Square Head Bolt
    from $3.10
  7. 3/8" Dia. Smooth Square Head Bolt
    3/8" Dia. Smooth Square Head Bolt
    from $1.19
  8. 3/8" Dia. Hammered Square Head Bolt
    3/8" Dia. Hammered Square Head Bolt
    from $2.59
  9. 3/8" Dia. Pyramid Square Head Bolt
    3/8" Dia. Pyramid Square Head Bolt
    from $2.71
  10. 1/2" Dia. Smooth Square Head Bolt
    1/2" Dia. Smooth Square Head Bolt
    from $3.48
  11. 1/2" Dia. Hammered Square Head Bolts
    1/2" Dia. Hammered Square Head Bolts
    from $4.85
  12. 1/2" Dia. Pyramid Square Head Bolt
    1/2" Dia. Pyramid Square Head Bolt
    from $5.51
  13. 5/8" x 7" Smooth Square Head Bolt Bulk Box (50) Nuts & Bolts Bolt
    5/8" Smooth Square Head Bolt
    from $6.62
  14. 5/8" Hammered Square Head Bolt
    5/8" Hammered Square Head Bolt
    from $7.99
  15. 5/8" Pyramid Square Head Bolt
    5/8" Pyramid Square Head Bolt
    from $8.65
  16. 3/4" x 9" Smooth Square Head Bolt- Bulk Lot (50)
    3/4" x 9" Smooth Square Head Bolt- Bulk Lot (50)
    $2,884.05 from $1,360.48
    finish
    Sale
  17. 3/4" Dia. Hammered Square Head Bolt
    3/4" Dia. Hammered Square Head Bolt
    from $12.46
  18. 3/4" Dia. Pyramid Square Head Bolt
    3/4" Dia. Pyramid Square Head Bolt
    from $13.13
  19. 5/8" x 7" Smooth Square Head Bolt Bulk Box (50) Nuts & Bolts Bolt
    5/8" x 7" Smooth Square Head Bolt Bulk Box (50)
    $966.54 $946.60
    Sale
  20. 1" x 5" Square Head Machine Bolts Nuts & Bolts Bolt
    1" x 5" Square Head Machine Bolts
    $13.87
  21. Ornate Tapered Square Head Bolt 1/4" dia. x 1" length
    Ornate Tapered Square Head Bolt 1/4" dia. x 1" length
    $1.13

Tool Talk:

Everything You Need to Know About Lag Bolts

If you are a DIYer, then you have probably heard of lag bolts. But what are these exactly? Here's everything you need to know about this fastener.

LEARN MORE
Image showing a combination of tools and decorative items, blending function and style

Top 12 Uses of Lag Bolts and Decorative Bolts for Your Home Decor

Looking for the best lag bolts and decorative bolts to spruce up your home decor? Then check out some of these examples that might be perfect for you.

LEARN MORE
Decorative hammered square head lag screw, combining unique design and utility in one fastener

Hammered Lag Bolts Vs. Smooth: Which Is Right for You?

Pair large text with an image to give focus to your chosen product, collection, or blog post. Add details on availability, style, or even provide a review.

LEARN MORE