Hex Bolts

Hex Bolts
Hex Bolts
Hex bolts fall under The American Society of Mechanical Engineers’ (ASME) standard category “Bolts, Studs and Threaded Rod”.  These bolts are fully threaded or partially threaded depending on the length with a six sided, hexagonal head.  
The ASME standard covers hex bolt dimensional specifications designated by ASME B18.2.1.  The chemical and mechanical specifications included in ASME B18.2.1 are governed by The Society of Automotive Engineers (SAE) and American Society for Testing and Materials (ASTM).  

Hex Bolt Specifications

  • ASME B18.2.1 - Bolt, Stud and Threaded Rod Dimensions
Body Diameter (E)
Bolt Length (L)
Head Height (H)
Radius of Fillet (R)
Thread Length (LT)
Transition Thread Length (Y)
Width Across Flats (F)
Width Across Corners (G)
  • SAE J429 - Mechanical and material requirements for externally threaded fasteners
  • ASTM A193 - Alloy steel and stainless steel bolting materials for high temperature or high pressure service and other special purpose applications
  • ASTM A307 - Carbon steel bolts and studs, 60,000 PSI tensile strength
  • ASTM A320 - Alloy steel and stainless steel bolting materials for low temperature service
  • ASTM A354 - Quenched and tempered alloy steel bolts, studs, and other externally threaded fasteners
  • ASTM A449 - Hex cap screws, bolts and studs, steel, heat treated, 120/105/90 ksi minimum tensile strength, general use
  • ASTM F468 - Nonferrous bolts, hex cap screws and studs for general use
  • ASTM F593 - Stainless steel bolts, hex cap screws and studs


How to Designate Bolts

Product Name:  Hex Bolt
Specification Standard:  ASME B18.2.1
Nominal Size (basic diameter):  1/2 or 0.500
Threads per Inch:  13
Length:  1.000
Material (specification and type where applicable):  ASTM A307
Grade:  A
Finish / Plating:  Hot Dip Galvanized (HDG)

          Hex Bolt, ASME B18.2.1, 1/2-13x1.000, ASTM A307, Grade A, HDG

For more information on hex bolts or for assistance in selecting the correct bolt for your application, please contact AALL AMERICAN Fasteners at 877-791-4426.

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