ASTM A325

Prior to its withdrawal in 2016, the ASTM A325 specification covered high strength heavy hex structural bolts from 1/2″ diameter through 1-1/2″ diameter. These bolts are intended for use in structural connections and therefore have shorter thread lengths than standard hex bolts. Refer to the Structural Bolts page of our site for thread lengths and other related dimensions.

This specification is applicable to heavy hex structural bolts only. For bolts of other configurations and thread lengths with similar mechanical properties, see Specification A449.

Bolts for general applications, including anchor bolts, are covered by Specification A449. Also refer to Specification A449 for quenched and tempered steel bolts and studs with diameters greater than 1-1/2″ but with similar mechanical properties.

A325 Types

TYPE 1

Medium carbon, carbon boron, or medium carbon alloy steel.

TYPE 2

Withdrawn November 1991.

TYPE 3

Weathering steel.

T

Fully threaded A325.(Restricted to 4 times the diameter in length)

M

Metric A325.

A325 Connection Types

SC

Slip critical connection.

N

Bearing type connection with threads included in the shear plane.

X

Bearing-type connection with threads excluded from the shear plane.

A325 Mechanical Properties

Size

Tensile, ksi

Yield, ksi

Elong. %, min

RA %, min

12- 1

120 min

92 min

14

35

118- 112

105 min

81 min

14

35

A325 Type 1 Chemical Properties

Heat Analysis

120ksi, %

150ksi, %

Carbon

0.30 – 0.52

0.30 – 0.48*

Manganese

0.60 min

0.60 min

Phosphorus

0.035 max

0.035 max

Sulfur

0.040 max

0.040 max

Silicon

0.15 – 0.30

-

Boron

0.003 max

0.003 max

Copper

-

-

Nickel

-

-

Chromium

-

-

Molybdenum

-

-

*Carbon 0.35-0.53% for 1-1/2” A490/150ksi bolts

A325 Type 3 Chemical Properties

Heat Analysis

120ksi, % Comp A

120ksi, % Comp B

120ksi, % Index

150ksi, % Index

Carbon

0.33 – 0.40

0.38 – 0.48

0.30 – 0.52

0.30 – 0.53

Manganese

0.90 – 1.20

0.70 – 0.90

0.60 min

0.60 min

Phosphorus

0.035 max

0.035 max

0.035 max

0.035 max

Sulfur

0.040 max

0.040 max

0.040 max

0.040 max

Silicon

0.15 – 0.30

0.30 – 0.50

Copper

0.25 – 0.45

0.20 – 0.40

0.20 – 0.60

0.20 – 0.60

Nickel

0.25 – 0.45

0.50 – 0.80

0.20 min*

0.20 min*

Chromium

0.45 – 0.65

0.50 – 0.80

0.20 min

0.20 min

Molybdenum

0.06 max

0.10 min*

0.10 min*

*Either Nickel or Molybdenum must be present in the amount specified *Corrosion Index based on ASTM Guide G101

Note:   In 2016, ASTM A325 was officially withdrawn and replaced by ASTM F3125, in which A325 now becomes a grade under the F3125 specification. The F3125 specification is a consolidation and replacement of six ASTM standards, including; A325, A325M, A490, A490M, F1852, and F2280. We are choosing to keep this technical information about the now obsolete A325 specification on our website for reference and informational purposes only.