Pursuant to Federal and State Nexus tax laws, several states, that we ship products to, have requested we pay their state sales tax. 

On November 1. 2020 Blacksmiths Depot will begin collecting taxes for those states.

5/16-18 x 8.5" machine Bolts

In stock
5/16" Square head machine Bolts
Item #
5/16" Square head machine Bolts
5/16" Square head machine Bolts
5/16" Square head machine Bolts

Great Old-Fashioned Square head Machine Bolts for a much more traditional look.  Some of the machine bolts we sell are old stock and finish can vary from flat to glossy

500 piece discount = 20% off

1000 piece discount = 30% off

  • Black Oxide, followed by an appropriate post-treatment, provides limited added corrosion protection to the surface of the metal, prolonging service and increasing the shelf-life of stored parts. 

Standard Thread Length - If you have a specific thread length you need please call to verify.  The minimum thread length shall be equal to one-half the nominal screw length plus 1/2" or 6”, whichever is less. However some of our stock is truly custom and therefore please call if you need a specific thread length.

More Information
shank diameter 5/16
thread 5/16-18
length below head 8.5"
finish coating Black Oxide
package quantity each
Write Your Own Review
You're reviewing:5/16-18 x 8.5" machine Bolts
Your Rating