ASTM A490

ASTM A490 and ASTM A490M are ASTM International standards for heavy hex structural bolts made from alloy steel. The imperial standard is officially titled Standard Specification for Structural Bolts, Alloy Steel, Heat Treated, 150 ksi Minimum Tensile Strength, while the metric standard (M) is titled Standard Specification for High-Strength Steel Bolts, Classes 10.9 and 10.9.3, for Structural Steel Joints.[1][2]

Contents

Types

The type refers to the type of material used. The standard currently defines two types, however it previously defined the following three:[1][2]

Note that independent of the material the bolt is quench and tempered.[4]

Connection types

There are also three connection types defined:[5]

Mechanical properties

These bolts are equivalent to ASTM A325 bolts in application and geometry, but are made to a higher strength. The imperial grades are made to the same strength specifications as ASTM A354 grade BD. The metric grades are made to the same strength specifications as ASTM F568M property class 10.9.[3] Also, unlike their weaker counterparts they cannot be coated by hot-dip galvanization, mechanical deposition, or electroplating.[5]

Because these bolts are designed to be used in structural applications the threaded length of the bolts are shorter to keep the threads out of the joint.[5]

Imperial head markings and mechanical properties[6]
Head marking Grade Nominal size range [in] Proof strength [ksi] Yield strength (min) [ksi] Tensile strength (min) [ksi] Core hardness [Rockwell]
Type 1 1⁄2–1-1⁄2 120 130[7] 150 minimum
173 maximum[1]		 C33–38
Type 2 1⁄2–1
[8] Type 3 1⁄2–1-1⁄2
Head markings and strengths for metric hex-head cap screws[2][3][9]
Head marking Grade Nominal size range [mm] Proof strength [MPa] Yield strength (min) [MPa] Tensile strength (min) [MPa] Core hardness [Rockwell]
Type 1 12–36 830 940 1040 C33–39
Type 2[4]
Type 3

References

  1. ^ a b c ASTM A490 - 08b, http://www.astm.org/Standards/A490.htm, retrieved 2009-06-23 .
  2. ^ a b c ASTM A490M - 09, http://www.astm.org/Standards/A490M.htm, retrieved 2009-06-23 .
  3. ^ a b c Metric structural fasteners, http://www.icaen.uiowa.edu/~sdesign1/Text/fasteners_si.html, retrieved 2009-06-06 .
  4. ^ a b Fastener identification marking, http://files.buildsite.com/dbderived-f/industrialthreadedproducts/derived_files/derived331165.pdf, retrieved 2009-06-23 .
  5. ^ a b c ASTM A490, http://www.portlandbolt.com/technicalinformation/astm/ASTM_A490.html, retrieved 2009-06-23 .
  6. ^ Grade Markings: Carbon Steel Bolts, http://www.fastspecinc.com/technical/technical.html, retrieved 2009-05-30 .
  7. ^ ASTM, SAE and ISO grade markings and mechanical properties for steel fasteners, http://www.americanfastener.com/technical/grade_markings_steel.asp, retrieved 2009-06-06 .
  8. ^ Other markings may be used to denote atmospheric corrosion resistant material
  9. ^ Metric Handbook, http://web.archive.org/web/20071031104609/www.blm.gov/nhp/efoia/wo/handbook/h9102.html, retrieved 2009-06-06 .